JP4381963B2 - Plasma processing equipment - Google Patents

Description

  The present invention relates to a plasma processing apparatus such as a dry etching apparatus or a plasma CVD apparatus used for manufacturing a thin film circuit such as a semiconductor, an electronic component, or a substrate on which the electronic component is mounted.

  Conventionally, as one of plasma processing apparatuses used for manufacturing a thin film circuit such as a semiconductor, an electronic component, or a substrate, a vacuum is applied by applying high-frequency power to a plasma excitation coil or electrode located outside a vacuum vessel. There is a high-frequency plasma excitation type plasma processing apparatus that excites plasma in a container and performs plasma processing on a substrate (workpiece) or the like disposed in the vacuum container with the excited plasma. This type of plasma processing apparatus generates a high-frequency electromagnetic field outside the vacuum vessel, transmits the high-frequency electromagnetic field to the inside of the vacuum vessel through a dielectric window, and accelerates electrons by this electromagnetic field to excite the plasma. Then, the processing is performed.

  As an example of such a conventional plasma processing apparatus, a schematic cross-sectional view of a plasma processing apparatus 500 is shown in FIG. 10 (see, for example, Patent Document 1, Patent Document 2, or Patent Document 3).

  As shown in FIG. 10, the plasma processing apparatus 500 is a bottomed body having a substantially cylindrical shape, and a vacuum vessel 501 (only a part of the vacuum vessel 501 is shown in FIG. 10), And a bell jar (dielectric window) 502 formed of a substantially hemispherical dielectric material (for example, quartz) provided so as to close the opening in the upper portion of the vacuum vessel 501, and the vacuum vessel 501 and the bell jar A processing chamber 503 is formed which is a sealed space with 502 and in which plasma processing is performed. Further, the plasma processing apparatus 500 is provided at the upper part of the side surface of the vacuum vessel 501, a reaction gas supply unit 504 that introduces a predetermined reaction gas into the vacuum vessel 501, and air in the vacuum vessel 501 (in the processing chamber 503) A vacuum pump (not shown), which is a vacuum exhaust device for exhausting gas, is provided. Further, in the vicinity of the upper side of the bell jar 502, a plasma excitation coil 505 formed in a spiral shape by a linear conductor is disposed, and a coil high frequency power source 506 for applying high frequency power to the coil 505 is provided. Further, a substrate electrode 507 is provided in the vicinity of the approximate center in the vacuum vessel 501, and a substrate electrode high-frequency power source 508 that applies high-frequency power to the substrate electrode 507 is provided. In addition, a substrate 509 on which plasma treatment is performed is held on a substrate electrode 507 in the vacuum vessel 501.

  Further, as shown in FIG. 10, in order to prevent the electromagnetic field generated from the coil 505 to which high frequency power is applied from escaping to the outside of the apparatus, the coil 505 and the bell jar 502 are provided by an earth shield 510 formed of a conductor member. Covered. The earth shield 510 is provided with a ventilation hole 511 at the left end in the figure and a cooling fan 512 at the right end in the figure. The cooling fan 512 exhausts the air in the earth shield 510 to the outside of the apparatus, and the ventilation hole 511. In addition, air outside the apparatus can be introduced into the earth shield 510.

  In the conventional plasma processing apparatus 500 having such a configuration, air is exhausted from the vacuum vessel 501 (that is, the processing chamber 503) by the vacuum pump, and a predetermined reaction gas is supplied from the reaction gas supply unit 504. While being introduced, the inside of the processing chamber 503 is kept at a predetermined pressure. In such a state, a high frequency power is applied to the coil 505 by the coil high frequency power source 506, an electromagnetic field is applied from the coil 505 to the reaction gas in the processing chamber 503 via the bell jar 502, and the plasma is excited. Using this excited plasma, plasma treatment such as etching, deposition, or surface modification can be performed on the substrate 509 held by the substrate electrode 507. At this time, ion energy reaching the substrate 509 can be controlled by applying high-frequency power to the substrate electrode 507 from the high-frequency power source 508 for substrate electrode.

  Further, during such plasma treatment, the temperature of the bell jar 502 and the coil 505 increases with the application time of the high frequency, but the atmosphere in the space inside the earth shield 510 is caused by the cooling fan 512 and the vent hole 511. Because of mechanical ventilation, the temperature rise can be reduced a little.

  Furthermore, the schematic cross section of the plasma processing apparatus 600 concerning another conventional example is shown in FIG. 11 (for example, refer patent document 4 or patent document 5). As shown in FIG. 11, the plasma processing apparatus 600 has a configuration different from that of the above-described plasma processing apparatus 500 in that a flat dielectric window 602 is provided instead of the substantially hemispherical bell jar 502. is doing. Specifically, the plasma processing apparatus 600 includes a bottomed and substantially cylindrical vacuum vessel 601, a flat dielectric window 602, a reactive gas supply unit 604, a planar spiral coil 605, and a coil high frequency. A power source 606, a substrate electrode 607 on which the substrate 609 can be placed and held, a substrate electrode high frequency power source 608, a ground shield 610, and a vacuum pump 613 are provided. The upper opening of the vacuum vessel 601 is closed and sealed by a dielectric window 602, and the sealed internal space is a plasma processing chamber 603. A matching unit 606a is provided between the coil high-frequency power source 606 and the coil 605, and a matching unit 608a is also provided between the substrate electrode high-frequency power source 608 and the substrate electrode 607.

  As shown in FIG. 11, a ventilation hole 611 is formed on the side surface of the earth shield 610, and a cooling fan 612 is provided above the matching unit 606a, and the earth shield 610 is connected to the matching unit 606a. There is a large opening in the center of the. Since the cooling fan 612 and the ventilation hole 611 are provided in this manner, the dielectric window 602 and the coil 605 that are heated during the plasma processing can be cooled by external air, and the temperature increase can be suppressed a little. .

  Further, an internal liquid path 614 capable of circulating the cooling / heating medium liquid is formed inside the substrate electrode 607, and the liquid path 614 communicates with the chiller unit 615 installed outside the apparatus through the cooling / heating medium liquid circulation path 616. Has been. In addition, as such a cold / warm fluid, for example, water, ethylene glycol, fluorine-based oil, or the like is used. The chiller unit 615 is provided with a pump for circulating the cooling / heating medium liquid, a refrigerator, a heater, a water cooling (air cooling) device for the refrigerator, and the like. Such a chiller unit 615 can cool the substrate electrode 607 that is heated during the plasma treatment, thereby suppressing the temperature increase. In addition, the substrate electrode 607 can be heated in advance in preparation for the plasma treatment.

JP 2003-59904 A US Pat. No. 5,540,824 JP-A-9-74089 JP 2000-21858 A JP-A-3-79025

  However, in the conventional plasma processing apparatus 500, the space inside the ground shield 510 that covers the bell jar 502 and the coil 505 is mechanically ventilated by the small-diameter cooling fan 512 and the vent hole 511, thereby cooling the bell jar 502 and the like that are heated. For this reason, the bell jar 502 may rise to, for example, about 200 ° C. as the electromagnetic field discharge time elapses due to insufficient cooling capacity. This tendency becomes prominent when the discharge time exceeds 3 minutes. As described above, when the temperature of the bell jar 502 is increased, the gas component is released from the adhesion film deposited on the inner wall of the bell jar 502, and the atmosphere of the plasma processing region R in the processing chamber 503 is generated. To change.

  In addition, when the plasma processing is stopped or the plasma processing apparatus 500 is on standby, the temperature of the bell jar 502 is also lowered to room temperature. In such a case, since the temperature of the dielectric window is low, film deposition on the dielectric window is promoted during the next plasma processing, and the adhesion film remains in the plasma processing region R. Adsorbs gas components and becomes a degassing source at the next temperature rise. By repeating the execution of the plasma treatment and the stop of the treatment, the atmosphere in the plasma treatment region R is not stable (constant), the number of treatments is increased, and the thickness of the attached film is increased to change the atmosphere. As a result, there is a problem that plasma processing with excellent reproducibility cannot be performed.

  Further, by repeating such plasma treatment and plasma stop, the quartz of the bell jar 502 and the adhesion film repeatedly rise and fall, and the adhesion film peels off due to the difference in coefficient of thermal expansion between them. Is generated, and dust adheres to the substrate 509 placed on the substrate electrode 507, causing a problem in the device on the substrate to be processed.

  Further, in the plasma processing, ozone may be generated by corona discharge around the coil 505 and ultraviolet light during plasma emission, and the generated ozone may diffuse outside the plasma processing apparatus 500 by cooling air. In such a case, there is a problem of health of workers, and there is a problem of accelerating deterioration of device parts.

  Each of these problems may occur in the plasma processing apparatus 600 as well. However, the plasma processing apparatus 600 uses a flat dielectric window 602 instead of a substantially hemispherical shell, and thus the processing chamber. In order to withstand the vacuum of 603 (that is, to withstand atmospheric pressure), the thickness dimension must be increased, and the dielectric window 602 may be formed of quartz, which is a material having a low heat transfer coefficient. In addition, the dielectric window 602 is further difficult to be cooled.

  Accordingly, an object of the present invention is to solve the above problem, and even if the plasma treatment is repeatedly performed, the stable plasma treatment can be performed with high reproducibility, and the amount of dust generated in the treatment chamber is increased. It is an object of the present invention to provide a plasma processing apparatus that can reduce the amount of gas.

  In order to achieve the above object, the present invention is configured as follows.

According to the first aspect of the present invention, in the plasma processing apparatus for exciting the plasma by applying an electromagnetic field to the reaction gas introduced into the evacuated processing chamber and performing plasma processing on the substrate in the processing chamber,
A vacuum container forming the processing chamber in which the substrate is held and processing is performed on the substrate;
A dielectric window forming part of the vacuum vessel so as to seal the processing chamber;
The dielectric through a window disposed opposite to the processing chamber, a high frequency power is applied, a plasma excitation coil via the dielectric window to impart an electromagnetic field to the interior of the processing chamber,
A gas supply unit for supplying the reaction gas into the processing chamber;
A vacuum exhaust system to keep a constant pressure of the processing chamber is evacuated to the process chamber,
A high frequency power supply for applying a high-frequency power to the plasma excitation coil,
A liquid chamber containing the liquid is contained therein so that the surface of the dielectric window opposite to the surface on the processing chamber side is immersed in an electrically insulating liquid. formed in, and a liquid container for disposing the plasma excitation coil to the liquid chamber,
In the liquid container, the liquid chamber is communicated with the first chamber so that the first chamber to which the electrically insulating liquid is supplied and the liquid supplied to the first chamber can be supplied therein, A liquid chamber partitioning member that divides the surface of the dielectric window on the liquid chamber side and the second chamber in which the plasma excitation coil is disposed;
In the liquid chamber, a support guide member that supports the liquid chamber partition member while guiding the partition position of the first chamber and the second chamber in a variable direction,
Due to the pressure difference between the liquid housed in the first chamber and the liquid housed in the second chamber, the plasma excitation coil is pressed and brought into close contact with the surface of the dielectric window on the liquid chamber side. A plasma processing apparatus is provided.

According to a second aspect of the present invention, in the second chamber of the liquid chamber accommodating container, and gap the liquid chamber partitioned member and the dielectric window of the plasma excitation coil wound around the screw spiral to provide a plasma processing apparatus according to a first aspect of liquid flow path surrounded by threaded spiral is formed.

According to a third aspect of the present invention, in the second chamber of the liquid chamber accommodating container, the upper Kinishi from the center side of the liquid flow path helically toward the outer circumferential side can flow is the electric insulating liquid The plasma processing apparatus according to the second aspect , in which the supply position of the liquid from the first chamber to the second chamber is disposed on the center side of the liquid flow path.

According to the first state like the present invention, is sealed by the dielectric window with the above-described vacuum vessel and the opposed, liquid container to form a liquid accommodating portion for electrically insulating liquid is contained therein cooled by is provided, for example, to adjust the temperature of the electrically insulating liquid contained in the liquid containing portion (cool or heat) that is, the plasma excitation coil via an electrically insulating liquid Alternatively, the temperature of the dielectric window can be adjusted to a desired temperature by heating.

For example, when the plasma processing for the substrate which is the holding is carried out, it becomes possible to the dielectric window is raised, cooling the upper Symbol electrically insulating liquid, in contact with the electrically insulating liquid The amount of heat accompanying the temperature rise can be removed from the surface of the dielectric window, and the temperature rise of the dielectric window can be suppressed. Such suppression of temperature rise suppresses the release of gas components into the processing chamber from the deposited film formed on the inner surface of the dielectric window (that is, the surface on the processing chamber side). it can.

On the other hand, the plasma untreated during (e.g., waiting for the plasma treatment, or plasma after treatment completion) in, with respect to the dielectric window to be cooled, the temperature decrease of the dielectric window by performing pressurized heat It can be suppressed and kept within the predetermined temperature range. Thereby, film deposition on the dielectric window during plasma processing can be suppressed, and the deposited film can be prevented from adsorbing gas components in the processing chamber. Accordingly, it is possible to suppress the release and adsorption of gas components generated by repeating the plasma treatment and non-treatment, and it is possible to stabilize the atmosphere in the treatment chamber and perform highly reproducible plasma treatment. .

  In addition, the plasma excitation coil is disposed in the liquid storage portion in which the electrical insulating liquid is stored. For example, the coil is immersed in the electrical insulating liquid, so that the dielectric The surface temperature of the coil can be adjusted simultaneously with the temperature adjustment of the body window. For example, the temperature rise can be suppressed by cooling the coil that is heated by applying the high-frequency power during the plasma treatment via the electrically insulating liquid. Proactively lowering the surface temperature of the coil by such cooling can suppress an increase in the substrate temperature due to infrared radiation accompanying the excessive temperature rise of the coil, and also causes deterioration due to thermal oxidation of the coil itself. Can be prevented. The temperature adjustment effect of the dielectric window and the plasma excitation coil as described above is sufficient even when the plasma processing time is 3 minutes or more and several hours, and the temperature fluctuation is minimized.

  Further, the temperature adjustment of the dielectric window and the plasma excitation coil is not performed by air ventilation as in the prior art, but the electrically insulating liquid in contact with the dielectric window and the coil. Is performed by heat transfer between the electrically insulating liquid and the dielectric window and the coil, thereby improving the heat transfer and stabilizing the temperature by the heat capacity of the liquid with a large capacity against intermittent plasma heating. Therefore, the efficiency of the temperature control and the controllability can be improved.

Further, like the conventional plasma processing apparatus, the coil and the dielectric can be mechanically ventilated (by taking in fresh air from the outside of the apparatus and releasing the surrounding air to the outside of the apparatus). instead of performing the cooling of the window, in the above-described plasma processing apparatus of the first state-like, by adjusting the temperature of the electrically insulating liquid contained in the liquid storage portion to place the coil therein, It does not generate ozone so order to cooling such as the coil can row a Ukoto, separation binding of oxygen molecules in the air by corona discharge or ultraviolet in the air no. Therefore, it is possible to improve the health problems of workers and to reliably prevent the deterioration of the device components of the device and peripheral devices due to ozone diffusion.

In the liquid container, the liquid chamber communicates with the first chamber to which the electrically insulating liquid is supplied, the surface of the dielectric window on the liquid chamber side, and the plasma excitation The coil is divided into the second chamber in which the coil is arranged by the liquid chamber dividing member, and further, the dividing position of the first chamber and the second chamber can be changed, so that the coil is accommodated in the first chamber. The plasma excitation coil can be pressed and brought into close contact with the surface of the dielectric window on the liquid chamber side due to a pressure difference between the liquid and the liquid stored in the second chamber. Therefore, by applying high-frequency power to the coil in the close contact state, a high voltage can be induced on the surface of the dielectric window on the processing chamber side, and discharge starts in the processing chamber even at low pressure. Or it can make it easy to maintain discharge.

  Embodiments according to the present invention will be described below in detail with reference to the drawings.

(First embodiment)
FIG. 1 shows a schematic cross-sectional view of a plasma processing apparatus 800 which is an example of a plasma processing apparatus according to the first embodiment of the present invention.

  As shown in FIG. 1, a plasma processing apparatus 800 includes a vacuum vessel 801 that is a bottomed body and has a substantially cylindrical shape, and a substantially disc-shaped dielectric provided so as to close an opening in the upper portion of the vacuum vessel 801. A dielectric window (quartz plate) 802 formed of a material (for example, quartz), and a processing chamber 803 that is a space sealed by the vacuum vessel 801 and the dielectric window 802 and in which plasma processing is performed. Is formed.

  Further, as shown in FIG. 1, the vacuum vessel 801 is divided into a lower vacuum vessel 801b which is a lower part of a substantially cylindrical bottomed body and an upper vacuum vessel 801a which is an upper part and has an annular shape. The upper vacuum vessel 801a and the lower vacuum vessel 801b are coupled to each other to form the vacuum vessel 801. Note that a seal member, for example, an O-ring 828, is disposed at a joint portion between the upper vacuum vessel 801a and the lower vacuum vessel 801b, and airtightness at the joint portion is ensured.

  In the plasma processing apparatus 800, a plurality of reaction gases, which are examples of a reaction gas supply unit that is provided on the inner surface of the upper vacuum vessel 801a of the vacuum vessel 801 and introduces a predetermined reaction gas into the vacuum vessel 801, are provided. An exhaust passage 13b is connected to the supply hole 4 and an exhaust port 13a provided on the inner surface of the lower vacuum container 801b of the vacuum container 801, and air or gas exhausted in the vacuum container 801 (that is, the processing chamber 803). The vacuum pump 13 which is an example of the vacuum exhaust apparatus which performs is provided. Near the upper side of the dielectric window 802, a coil 805 (or a plasma excitation coil 805) which is an example of a plasma excitation coil formed in a spiral shape (spiral shape) by a flat conductor having a rectangular cross section. , Disposed along the outer surface of the dielectric window 802 (that is, the surface opposite to the surface on the processing chamber 803 side so as to face the processing chamber 803 via the dielectric window 802), A high frequency power source 806 for the coil that applies high frequency power to the coil 805 via the matching unit 818 is provided outside the vacuum vessel 801. Further, a lower electrode 7 which is an example of a substrate electrode is provided near the center of the vacuum vessel 801, and a lower electrode high frequency power source for applying high frequency power to the lower electrode 7 via a matching unit 19 is provided. 8 is provided outside the vacuum vessel 801. Further, the substrate 9 to be subjected to plasma processing by the plasma processing apparatus 800 is held on the lower electrode 7 in the vacuum vessel 801.

  In addition, as shown in FIG. 1, an earth shield formed of a conductor (conductive material such as aluminum or alloy) having a ground potential so as to cover the entire coil 805 disposed near the outer surface of the dielectric window 802. A container 810 (or an upper electrode case 810) is provided fixed to the upper part of the upper vacuum container 801a of the vacuum container 801. In addition, the central electrode 814 connected to the coil high-frequency power source 806 via the matching unit 818 is not electrically contacted with the earth shield container 810 near the center of the earth shield container 810. The central electrode 814 is connected to the end of the central portion of the spiral coil 805 via an application terminal 816. The end of the coil 805 on the outer peripheral side is connected to the earth shield container 810 via the earth terminal 817, and the earth shield container 810 is connected to the earth electrode of the high frequency power source 806 for the coil. Thereby, it is possible to apply high frequency power to the coil 805 from the coil high frequency power source 806 through the center electrode 814 and the application terminal 816. The coil 805, the center electrode 814, the application terminal 816, and the ground terminal 817 are each plated with gold, for example. Furthermore, a casing 819 in which the matching unit 818 is disposed is attached to the outer upper portion of the earth shield container 810. In order to remove the heat generated from the matching unit 818, the casing 819 has an air in its inside. A cooling fan 860 for mechanically ventilating the air is installed.

  In addition, as shown in FIG. 1, the above-described arrangement is achieved by fixing the earth shield container 810 to the upper part of the vacuum container 801 in a state where the dielectric window 802 is disposed so as to cover the opening part in the upper part of the vacuum container 801. It is possible to fix the dielectric window 802 in such a state in this arrangement. Further, with the dielectric window 802 fixed in this manner, the inner space of the earth shield container 810 is sealed by the outer surface (surface opposite to the processing chamber) of the dielectric window 802, and the coil A space in which 805 is arranged is formed. In this space, as will be described later, it is possible to store a cooling / heating medium liquid that is an example of an electrically insulating liquid, and the space is a liquid chamber 820 that is an example of a liquid storage part, Further, the earth shield container 810 is an example of a liquid storage container. Further, the lower surface of the dielectric window 802 in the figure is the processing chamber side surface, and the opposite surface is the liquid chamber sealing surface.

  Further, as shown in FIG. 1, in the liquid chamber 820, a groove portion 850a that engages with an upper portion of the spiral coil 805 shown on the outer surface of the dielectric window 802 is formed on the lower surface thereof. The formed disc-shaped coil holding plate 850 is disposed. That is, the coil 805 is disposed on the outer surface of the dielectric window 802 in the liquid chamber 820 in a state where the coil 805 is held on the lower surface of the coil holding plate 850 and its spiral shape is defined. The coil holding plate 850 has a disk-like outer shape that is substantially the same size as the shape of the inner side surface of the earth shield container 810, and slides along the side wall (circumferential surface) of the liquid chamber 820. It is arranged to be movable. Further, the coil holding plate 850 can guide the movement in the vertical direction (that is, the above-described sliding) in the figure by a plurality of guide bolts 851 which are examples of a support guide member fixed to the inner top plate of the earth shield container 810. The coil holding plate 850 is prevented from rotating and coming off inside the earth shield container 810 by the support. Further, an urging spring 852 is attached to each guide bolt 851, and the urging spring 852 moves the coil holding plate 850 along the dielectric window 802 along the guide bolt 851 arranged in the vertical direction in the figure. It has the function of always energizing towards

  In addition, since the coil holding plate 850 and the coil 805 are arranged in the liquid chamber 820 in this way, the liquid chamber 820 is made up of the upper chamber 820a and the second chamber which are examples of the first chamber by the coil holding plate 850. Are divided into two chambers, a lower chamber 820b. That is, in the first embodiment, the coil holding plate 850 is an example of a liquid chamber dividing member that divides the liquid chamber 820 into the two chambers. Further, since the support position of the coil holding plate 850 can be varied, the section position of the two chambers can also be varied by applying an external force, for example.

  The upper chamber 820a and the lower chamber 820b are communicated with each other through a through hole 850a formed in the approximate center of the coil holding plate 850. Further, the lower chamber 820b has a spiral shape because the lower surface of the coil 805 held by the coil holding plate 850 is in contact with the outer surface of the dielectric window 802. A space (gap) between the coils 805 is surrounded by the lower surface of the coil holding plate 850 in the drawing and the outer surface of the dielectric window 802 to form a spiral liquid flow path 854 of the cooling / heating medium liquid. That is, in the liquid chamber 820, the upper chamber 820a communicates with the central portion of the spiral liquid channel 854 formed in the lower chamber 820b through the through hole 850a.

  Further, the earth shield container 810 communicates with the cooling medium liquid supply hole 810b to the upper chamber 820a and the outer peripheral end of the spiral liquid channel 854 in the lower chamber 820b so as to penetrate the side wall. In addition, a discharge hole 810a for the cooling / heating medium liquid from the liquid flow path 854 is formed. Thus, by forming the supply hole 810b and the discharge hole 810a for the cooling / heating medium liquid, the cooling / heating medium liquid supplied from the supply hole 810b into the upper chamber 820a enters the lower chamber 820b through the through hole 850a. The cooling / heating medium liquid flows in and flows from the center of the spiral liquid channel 854 toward the outer peripheral end, and the cooling / warming medium liquid can be discharged through the discharge hole 810a at the outer peripheral end. A continuous liquid flow path of the cooling / warming fluid is formed in the liquid chamber 820. By forming such a continuous liquid flow path, it is possible to adjust the temperature of the dielectric window 802 and the coil 805 by adjusting the temperature of the cold medium liquid to be circulated. .

  Further, as shown in FIG. 1, a liquid flow path 823 through which the cooling / heating medium liquid can pass is formed inside the lower electrode 7, and the cooling / heating medium liquid adjusted to a desired temperature is supplied to the liquid flow path 823. It is possible to keep the lower electrode 7 at a desired temperature by flowing from the supply hole 823b, which is one end, to the discharge hole 823a, which is the other end.

  Further, for example, an annularly formed cooling / heating medium liquid flow path 853 is also formed in the upper vacuum container 801a of the vacuum container 801, and the cooling / heating medium liquid supply hole 853b and the discharge are provided in the liquid flow path 853. A hole 853a is formed. The cooling / heating medium liquid adjusted to a desired temperature is supplied into the liquid flow path 853 through the supply hole 853b and is discharged through the discharge hole 853a, thereby passing through the inner side surface of the upper vacuum vessel 801a and the processing chamber. The wall surface temperature in 803 can be adjusted to a desired temperature.

  In addition, a liquid channel 822 that is an example of a liquid channel that connects the supply holes 810b, 853b, and 823b, the discharge holes 853a, 823a, and the liquid channel 822 is connected to the chiller unit 821. It has been. The chiller unit 821 contains a refrigerator (an example of a cooling device) that cools the cold / warm fluid, a heater (an example of a heating device) that heats the cold / warm fluid, and the cold / warm fluid. A cooling / heating medium liquid tank, a pump which is an example of a liquid circulation apparatus for supplying (circulating) the cooling / heating medium liquid, a water cooling or air cooling apparatus for removing heat generated by the cooling operation of the refrigerator, The temperature control device 821a that controls the temperature of the cooling / heating medium liquid to a desired temperature by controlling the operation of the constituent parts, and the temperature detected by the temperature control device 821a while detecting the temperature of the cooling / heating medium liquid. And a temperature sensor 821b. The chiller unit 821 configured in this manner has a function of adjusting (controlling) the temperature of the cooling / heating medium liquid to a desired temperature by cooling or heating the cooling / heating medium liquid, and the temperature-controlled cooling / heating medium liquid. Is supplied to the inside of the liquid chamber 820 through the liquid flow path 822 and has a function of circulating and collecting the cold / warm medium liquid stored in the liquid chamber 820 through the liquid flow path 822.

  Specifically, as shown in FIG. 1, the cold / warm fluid sent out from the chiller unit 821 through the liquid flow path 822 is supplied to the liquid flow path 823 in the lower electrode 7 and discharged from the liquid flow path 823. The cooled / warm fluid is supplied into the liquid channel 853 in the upper vacuum vessel 801a through the liquid channel 822, and the cold / warm fluid discharged from the liquid channel 853 is supplied into the liquid chamber 820 through the liquid channel 822. A continuous circulation flow path is formed by the liquid flow path 822 so that the cold / warm fluid discharged from the liquid chamber 820 is returned to the chiller unit 821 through the liquid flow path 822 again.

  In FIG. 1, the case where the temperature sensor 821b is installed in the vicinity of the outlet of the cold / warm fluid in the chiller unit 821 has been described. However, the arrangement of the temperature sensor 821b is not limited to such a case. Absent. For example, it may be installed in a tank or the like inside the cold / warm medium liquid in the chiller unit 821, or the temperature of the cold / warm medium liquid in the liquid chamber 820 can be detected, It may be the case where it is installed in.

In addition, as such a cooling / heating medium liquid, for example, fluorine-based inert oil typified by Florinart and Galden (both trade names or trademarks), silicon-based oil, pure water, other organic oils and fats, etc. Insulating oil can be used. Since these liquids have electrical insulating properties, even if they contact a coil 805 formed of a conductive material and to which high frequency power is applied, they are characterized in that no short circuit or leakage occurs. Since it is also a dielectric, the electrostatic field generated inside the processing chamber 803 through the dielectric window 802 can be increased. In addition, as said pure water, in order to ensure the electrical insulation, what has a resistivity of 1 * 10 < ⁵ > ohm * cm or more is used.

  Further, in the plasma processing apparatus 800, the joint portion between the dielectric window 802 and the vacuum vessel 801, the joint portion between the vacuum vessel 801 and the earth shield vessel 810, and the joint portion between the upper vacuum vessel 801a and the lower vacuum vessel 801b described above. Are provided with O-rings 826, 827, and 828, respectively, and the airtightness of the processing chamber 803 and the liquid chamber 820 is secured.

  Furthermore, in the plasma processing apparatus 800, the operation control of the high frequency power application operation by the coil high frequency power source 806, the high frequency power application operation by the lower electrode high frequency power source 8, and the vacuum exhaust operation by the vacuum pump 13 are associated with each other. A control device 90 that performs overall control is provided. Such a control device 90 performs the above overall control, so that the plasma processing can be performed on the substrate 9 placed on the lower electrode 7. In addition, the temperature adjustment operation of the cooling / heating medium liquid by the chiller unit 821 (that is, the temperature control operation by the temperature control device 821a) is normally performed autonomously in the chiller unit.

  A method of performing plasma processing on the substrate 9 by the plasma processing apparatus 800 having such a configuration will be described. Note that the following operations are performed as overall control by the control device 90 while being associated with each other.

  First, in FIG. 1, a substrate 9 that is an object to be processed to be subjected to plasma processing is placed on the lower electrode 7 in the vacuum vessel 801. Next, the processing chamber 803 is hermetically sealed, and the air or gas in the processing chamber 803 is exhausted through the exhaust port 13a and the exhaust passage 13b by the vacuum pump 13, and subsequently, a reaction gas supply hole is formed from a reaction gas supply device (not shown). 4, a predetermined reaction gas is supplied, and the inside of the processing chamber 803 is kept at a predetermined pressure by adjusting an exhaust flow rate with an exhaust flow rate adjustment valve (not shown) provided in the middle of the exhaust passage 13 b, for example. .

  At the same time, the cooling / heating medium liquid controlled to a predetermined temperature by the chiller unit 821 is passed through the liquid flow path 822, the liquid flow path 823 in the lower electrode 7, the liquid flow path 853 in the upper vacuum vessel 801 a, and the liquid chamber 820. The cooling / heating medium liquid is circulated so that the supplied cooling / heating medium liquid is recovered by the chiller unit 821 through the liquid flow path 822. Due to the circulation of the cooling / heating medium liquid, in the liquid chamber 820, the cooling / heating medium liquid is supplied from the liquid flow path 822 through the supply hole 810b into the upper chamber 820a, and the supplied cooling / heating medium liquid passes through the through hole 850a. The cooling / heating medium liquid flows through the spiral liquid flow path 854 from the center side toward the outer peripheral end, and is discharged to the liquid flow path 822 through the discharge hole 810a. In this way, the cooling / heating medium liquid is circulated in the liquid chamber 820, so that the coil holding plate 851 is directed toward the dielectric window 802 due to the pressure difference between the cooling / heating medium liquid supplied into the upper chamber 820a and the lower chamber 820b. Is energized.

  In a state where the coil holding plate 851 is supported by a plurality of guide bolts 851, the support position thereof is constantly urged by a plurality of urging springs 852 toward the dielectric window 802, whereby the coil 805 is urged. The coil 805 is completely abutted against the surface of the dielectric window 802 due to the manufacturing accuracy of the dielectric window 802, the coil 805, and the coil holding plate 851. In some cases, it may not be possible. However, even in such a case, the coil holding plate 851 is urged by the liquid pressure of the cold / warm medium liquid having a force larger than the urging force by the plurality of urging springs 852, and the supporting position is set to the dielectric. By slightly moving to the window 802 side, the coil 805 held on the lower surface of the coil holding plate 851 is pressed against the outer surface of the dielectric window 802 and can be brought into close contact. . Further, the coil 805 is pressed through the coil holding plate 850 by the pressure difference between the cooling / heating medium liquid in the upper chamber 820a and the lower chamber 820b, so that the pressing force of the coil 805 to the dielectric window 802 is pressed. Can be made substantially uniform over the entire spiral contact surface. From such a viewpoint, it is desirable to determine the size and shape of the through hole 850a, the circulation flow rate of the cooling / warming fluid, and the like so that a pressure difference capable of generating a necessary and sufficient urging force is generated.

  While maintaining this state, a predetermined high frequency power is applied from the coil high frequency power source 806 to the coil 805 via the matching unit 818, the center electrode 814, and the application terminal 816. As a result, an electromagnetic field is applied from the coil 805 to the reaction gas in the processing chamber 803 through the dielectric window 802, electrons in the reaction gas molecules are accelerated, and plasma is excited in the processing chamber 803. At this time, the ion energy reaching the substrate 9 can be controlled by simultaneously applying the high frequency power to the lower electrode 7 from the lower electrode high frequency power supply 8 via the matching unit 19. Plasma treatment such as etching, deposition, or surface modification can be performed on the substrate 9 placed on the lower electrode 7 by the plasma thus excited.

  In addition, the cooling / heating medium liquid adjusted to a predetermined temperature by the chiller unit 821 is circulated through the liquid flow path 822, thereby cooling the dielectric window 802 and the coil 805 heated by the plasma treatment, The plasma treatment can be performed while keeping each temperature within a predetermined temperature range.

  Here, the “predetermined temperature range” refers to deposition that is a deposit by reducing the deposition amount of a thin film formed by deposition of reaction products on the inner surface of the dielectric window 802 during plasma processing. The temperature range is such that the formation of the film can be suppressed and the dielectric film 802 can be kept at a high temperature to prevent the deposition film from peeling (the volume film does not peel).

  Similarly, the plasma treatment is performed while keeping the temperature of the lower electrode 7 within a predetermined temperature range so that the substrate 9 to be treated heated by the plasma treatment is kept at an appropriate temperature by circulation of the cold / warm fluid. Can be performed. Furthermore, by circulating the cold medium liquid to the liquid flow path 853 in the upper vacuum vessel 801a, the temperature of the inner wall surface of the processing chamber 803 can be kept within a predetermined temperature range, and the volume Plasma treatment can be performed while suppressing film formation.

  Further, even when the plasma is not processed, the temperature of the dielectric window 802 can be kept within the predetermined temperature range by circulating the cooling / heating medium liquid controlled to a desired temperature by the chiller unit 821 to the liquid chamber 820. it can. In such a case, even when plasma is not processed, the temperature of the dielectric window 802 can be kept within the predetermined temperature range, and the temperature changes by repeating the plasma processing and the plasma non-processing. That is, it is possible to prevent the heat cycle from being applied to the deposited film formed on the dielectric window 802, and it is possible to prevent the deposited film from peeling off due to the heat cycle.

  According to the first embodiment, the following various effects can be obtained.

  First, in the liquid chamber 820 formed by being surrounded by the outer surface of the dielectric window 802 and the inner surface of the earth shield container 810, the cooling / heating medium liquid controlled to a desired temperature can be circulated. The outer surface of the dielectric window 802 that is in contact with the cooling / heating medium liquid can be cooled or heated through the cooling / heating medium liquid. Specifically, the temperature of the dielectric window 802 can be suppressed by cooling the dielectric window 802 that is heated during the plasma treatment. Such suppression of the temperature rise can suppress the release of the gas component into the processing chamber 803 from the formed deposited film. Further, when the plasma is not processed, the dielectric window 802 to be cooled can be heated to suppress the temperature drop of the dielectric window 802 and can be kept within the predetermined temperature range. Thereby, it is possible to prevent the deposited film from adsorbing the gas component in the processing chamber 803 and film deposition on the inner surface of the dielectric window 802 at the start of the next plasma processing.

  Therefore, it is possible to suppress the release and adsorption of gas components generated by repeating the plasma treatment and the non-treatment, and to stabilize the atmosphere in the plasma generation region R1 and perform a highly reproducible plasma treatment. Become. In addition, it is possible to prevent the deposited film attached to the inner surface of the dielectric window 802 from being peeled off by a heat cycle and causing a defect due to dust on the substrate to be processed.

  Further, the coil 805 is disposed in the lower chamber 820b of the liquid chamber 820 in which the cold / warm fluid is circulated and is immersed in the cold / warm fluid, thereby simultaneously with the dielectric window 802. The surface temperature of the coil 805 can also be controlled. Specifically, the temperature rise can be suppressed by cooling the coil 805, which is heated by application of high-frequency power during the plasma treatment, through the cooling medium liquid. By actively lowering the surface temperature of the coil 805 by such cooling, infrared rays radiated by the surface temperature of the coil 805 can be prevented from heating the substrate to be processed. The effect of the temperature adjustment on the dielectric window 802 and the coil 805 as described above is not impaired even when the plasma processing time is 3 minutes or more and several hours, and the temperature change can be minimized. .

  The liquid chamber 820 is divided into an upper chamber 820a and a lower chamber 820b by a coil holding plate 850 that holds the coil 805, and the cooling / heating medium liquid supplied to the upper chamber 820a is poured into the lower chamber 820b. By configuring the flow path of the cooling / heating medium liquid, the coil holding plate 850 is urged toward the lower chamber 820b side by the pressure difference between the cooling / heating medium liquid in the upper chamber 820a and the lower chamber 820b, thereby forming a spiral shape. The coil 805 can be pressed against the surface of the dielectric window 802 with a uniform force so as to adhere to the surface. In this manner, the coil 805 is brought into close contact with the surface of the dielectric window 802, so that a high-frequency high voltage applied to the coil 805 can be dielectrically formed on the surface of the dielectric window 802 on the processing chamber 803 side. However, it is possible to easily start or maintain the discharge. Accordingly, there is provided a plasma processing apparatus which can provide a strong electromagnetic field induction effect by the coil 805 in the processing chamber 803, can be discharged at a low pressure, has a high plasma density, and can improve an etching rate. be able to.

  Further, in the lower chamber 820b of the liquid chamber 820, a spiral liquid channel 854 is formed between the spiral coils 805, and the cooling / heating medium liquid is directed from the center side of the liquid channel 854 toward the outer peripheral end. Since the liquid flow path 854 is configured so as to circulate, the dielectric window 802 and the coil 805 can be cooled or heated substantially uniformly, and temperature adjustment is performed with high temperature controllability. be able to.

  Further, as such a cooling / heating medium liquid, for example, in the case of using a fluorine-based inert oil, the coil 805 is included in the fluorine-inactive oil because it has high insulation. Even if it is directly immersed in the battery, no leakage or the like occurs, and its safety is ensured. Furthermore, since such a fluorine-based inert oil has a feature that its usable temperature range is wide, it is suitable for temperature control of the dielectric window 802 and the like to a desired temperature from below freezing to 200 ° C. It can be said that it is a thing. Further, since the fluorinated oil is also a dielectric, a strong electrostatic field is generated in the processing chamber 803 through the fluorinated inert oil and the dielectric window 802 when high frequency power of the immersed coil 805 is applied. And the ignitability of plasma can be improved.

  In addition, the surface of each of the spiral coil 805, the application terminal 816, the ground terminal 817, and the center electrode 814 is gold-plated instead of silver-plated as conventionally applied, Corrosion and electrolytic corrosion can be prevented from occurring on the surface of the coil 805 and the like due to the application of the high frequency voltage and the moisture of the cooling / heating medium liquid.

  Further, mechanical ventilation of the air around the coils 505 and 605 is performed as in the conventional plasma processing apparatuses 500 and 600 (incorporating new air from the outside of the apparatus and releasing the surrounding air to the outside of the apparatus). Instead of cooling, the plasma processing apparatus 800 of the first embodiment is formed by being surrounded by the outer surface of the dielectric window 802 and the earth shield container 810, and the coil 805 is disposed therein. In order to cool the coil 805 and the like using the above-mentioned cooling / circulating fluid circulation system constituted by the liquid chamber 820, the liquid flow path 822, and the chiller unit 821, The ozone does not diffuse outside the device. Therefore, it is possible to improve the health problems of workers, and it is possible to reliably prevent deterioration of device components of the plasma processing apparatus and peripheral devices due to ozone diffusion.

(Second Embodiment)
In addition, this invention is not limited to the said embodiment, It can implement with another various aspect. For example, FIG. 2 shows a schematic cross-sectional view of a plasma processing apparatus 100 which is an example of a plasma processing apparatus according to the second embodiment of the present invention. As shown in FIG. 2, the plasma processing apparatus 100 includes the dielectric window 2 having a substantially hemispherical shape instead of the disk-shaped dielectric window 802, and the plasma processing apparatus 800 of the first embodiment. However, other configurations not related to the form of the dielectric window 2 are substantially the same as those of the plasma processing apparatus 800. Hereinafter, this different configuration will be mainly described. In order to facilitate understanding of the description, in the plasma processing apparatus 100, the same reference numerals are given to the same components as those in the plasma processing apparatus 800 of the first embodiment, and the description thereof is omitted. It shall be.

  As shown in FIG. 2, the plasma processing apparatus 100 includes a vacuum vessel 1 and a substantially hemispherical (or dome-like) dielectric material (for example, quartz) provided so as to close an opening in the upper portion of the vacuum vessel 1. ) (Formed as an example of a dielectric window) 2, and a space sealed by the vacuum vessel 1 and the bell jar 2 and a processing chamber 3 in which plasma processing is performed is formed. .

  In addition, the plasma processing apparatus 100 is connected to a plurality of reaction gas supply holes 4 provided in the upper part of the side surface of the vacuum vessel 1 and an exhaust port 13a of the vacuum vessel 1 through an exhaust passage 13b. And a vacuum pump 13 for exhausting air or gas in the processing chamber 3). Further, in the vicinity of the upper side of the bell jar 2, a coil 5, which is an example of a coil for plasma excitation formed in a spiral shape by a linear conductor, is disposed along the outer surface of the pel jar 2. A high frequency power source 6 for the coil that applies high frequency power via 18 is provided outside the vacuum vessel 1. Further, a lower electrode 7 is provided in the vicinity of the approximate center in the vacuum vessel 1, and a lower electrode high-frequency power source 8 that applies high-frequency power to the lower electrode 7 via a matching unit 19 is provided in the vacuum vessel 1. It is provided outside. In addition, the substrate 9 to be subjected to plasma processing by the plasma processing apparatus 100 is held on the lower electrode 7 in the vacuum vessel 1.

  In addition, as shown in FIG. 2, an earth shield container 10 (one liquid storage container) formed of a conductor (conductive material) having a ground potential so as to cover the entire coil 5 arranged near the outer surface of the bell jar 2. Is fixed to the top of the vacuum vessel 1. Further, near the center of the earth shield container 10, the center electrode 14 connected to the coil high frequency power supply 6 via the matching unit 18 is not in electrical contact with the earth shield container 10. The central electrode 14 is connected to the end of the central portion of the spiral coil 5 via the application terminal 16. Further, the end of the coil 5 on the outer peripheral side is connected to the earth shield container 10 via the earth terminal 17, and the earth shield container 10 is connected to the earth electrode of the coil high-frequency power source 6. Thereby, it is possible to apply high frequency power to the coil 5 from the coil high frequency power source 6 through the center electrode 14 and the application terminal 16.

  In addition, as shown in FIG. 2, a space surrounded by the inside of the earth shield container 10, the outer surface that is a part of the bell jar 2, and the upper part of the vacuum container 1, and the coil 5 is disposed therein. As a liquid chamber 20, it is possible to accommodate a cooling / heating medium liquid. Further, a discharge hole 10a for the cooling / heating medium liquid from the liquid chamber 20 is formed in the vicinity of the upper part of the earth shield container 10, and a supply hole for the cooling / heating medium liquid into the liquid chamber 20 is formed in the vicinity of the lower part. 10b is formed.

  Further, the supply hole 10b and the discharge hole 10a are connected to the upper chiller unit 21 through a flow path 22 which is an example of a liquid flow path so that the cooling / heating medium liquid can circulate. The upper chiller unit 21 detects the temperature of the cooling / heating medium liquid therein, and a cooling device, a heating device, a pump, a temperature control device 21a for controlling the temperature of the cooling / heating medium liquid to a desired temperature, and the like. In addition, a temperature sensor 21b that outputs the detected temperature is provided in the temperature control device 21a. The upper chiller unit 21 configured as described above can cool or warm the coil 5 and the bell jar 2 via the cooling / heating medium liquid, and can maintain the desired temperature. 21 is an example of a liquid temperature adjusting device for the cold / warm fluid.

  Further, as shown in FIG. 2, a liquid flow path 23 through which the cold / warm fluid can pass is formed inside the lower electrode 7, and the liquid flow path 23 is connected to the lower side via a flow path 24. A chiller unit 25 is connected. The lower chiller unit 25 has the same configuration as the upper chiller unit 21 and includes a temperature control device 25a, a temperature sensor 25b, and the like, and the cold temperature controlled to a desired temperature through the cold / warm fluid channel 24. By circulating the liquid medium in the liquid flow path 23, the lower electrode 7 can be maintained at a desired temperature.

  Further, in the plasma processing apparatus 100, O-rings 26 and 27 are provided at a joint portion between the bell jar 2 and the vacuum vessel 1 and a joint portion between the vacuum vessel 1 and the earth shield vessel 10, respectively. And the airtightness of the liquid chamber 20 is ensured.

  Further, the plasma processing apparatus 100 includes a control device 90 that controls the plasma processing operation by performing overall control while associating the operations of the respective components.

  Here, an embodiment showing various conditions in such plasma processing will be described. For example, when a via hole is etched to a depth of 100 μm in an InP (indium phosphide) substrate as a substrate, HI gas and Ar gas are supplied as reaction gases at a supply rate of 100 sccm (standard state: 100 cc / min). While the vacuum pressure is maintained at 1 Pa, a high frequency power having a frequency of 13.56 MHz and an output of 1000 w is applied to the coil 5 by the coil high frequency power source 6 while the vacuum pressure is maintained at 1 Pa. By applying high frequency power with a frequency of 13.56 MHz and an output of 100 w to 7, the etching process is performed on the substrate 9 held by the lower electrode 7. At this time, Galden is used as the cooling medium liquid, and the Galden is circulated in the liquid chamber 20 at a rate of 2 l / min, the temperature of the bell jar 2 is maintained at about 100 ° C. Hold. Under such conditions, the etching process can be performed on the substrate 9 in about 100 minutes.

  In the plasma processing apparatus 100 having such a configuration, the coil 5 is disposed in the liquid chamber 20 formed by the bell jar 2 and the earth shield container 10, and a predetermined temperature is introduced into the liquid chamber 20 during the plasma processing. The temperature of the bell jar 2 and the coil 5 can be kept within a predetermined temperature range by circulating the adjusted temperature / temperature medium liquid, and the same effect as the temperature adjustment of the temperature / temperature medium liquid in the first embodiment. Can be obtained.

  The method of the second embodiment shown in FIG. 2 can also be applied to the method using the flat dielectric window and the planar spiral coil shown in the first embodiment of FIG. However, the method using the hemispherical bell jar 2 can reduce the thickness of the bell jar as much as possible even with a dielectric material (for example, quartz) having a low thermal conductivity. Is advantageous. Therefore, from such a viewpoint, it can be said that there is an advantage of the method of controlling the temperature of the bell jar 2 by forming the liquid chamber 20 using the external surface of the bell jar 2.

  In the above description, the coil 5 is disposed in the liquid chamber 20 surrounded by the substantially hemispherical bell jar 2 and the earth shield container 10, and the cooling / heating medium liquid is circulated in the liquid chamber 20. Although the case has been described, the configuration of the plasma processing apparatus 100 of the second embodiment is not limited to such a case. For example, in the plasma processing apparatus configured such that the substantially hemispherical bell jar 2 is used, a configuration in which the coil is closely attached to the surface of the dielectric window as in the plasma processing apparatus of the first embodiment. It can also be applied. FIG. 3 shows a schematic configuration diagram showing a configuration of a plasma processing apparatus 900 according to a modification of the second embodiment to which such a configuration is applied. 4 is a cross-sectional view taken along line AA in the plasma processing apparatus 900 shown in FIG. In the plasma processing apparatus 900 shown in FIGS. 3 and 4, parts having the same configuration as that of the plasma processing apparatus 100 shown in FIG. 2 are denoted by the same reference numerals, and description thereof is omitted. To do.

  As shown in FIG. 3, in the plasma processing apparatus 900, a substantially conical spiral coil 905 having a rectangular cross section is disposed above the bell jar 2 in the liquid chamber 20. Further, as shown in FIGS. 3 and 4, the coil 905 is held on the lower surface of a coil holding member 950 having a substantially X shape in plan view. Such holding is performed, for example, by partially engaging the upper portion of the coil 905 with a plurality of groove portions 950 a formed on the lower surface of the coil holding member 950.

  In addition, the coil holding member 950 is supported inside the earth shield container 10 via a plurality of guide bolts 951 at each end of the X shape. Each guide bolt 951 is arranged in the vertical direction in the figure, and the coil holding member 950 is supported so as to be movable along each guide bolt 951. Further, urging springs 952 are attached to the respective guide bolts 951, and these urging springs 952 urge the coil holding member 950 along the respective guide bolts 951 to the upper side of the bell jar 2 in the figure. It has a function. With such a configuration, the coil 905 held on the lower surface of the coil holding member 950 is always pressed against the upper surface of the bell jar 2 shown in the drawing, and the coil 905 is in close contact with the surface of the bell jar 2. Is maintained.

  In the plasma processing apparatus 900, the spiral coil 905 disposed in the liquid chamber 20 is always in close contact with the upper surface of the bell jar 2 shown in the drawing, so that a high frequency is applied to the coil 905 during plasma processing. As a result, a strong electromagnetic field induction effect can be generated on the surface of the bell jar 2 on the processing chamber 3 side, and the same effect as the effect of the first embodiment in that discharge can be easily started or maintained even at a low pressure. Obtainable.

  In FIG. 3, the shape and arrangement of the ground terminal 17 and the application terminal 16 are different from the plasma processing apparatus 100 of FIG. 2, but such shape and arrangement are determined by the arrangement and shape of the coil 905. There is no substantial difference in functions. Further, as shown in FIG. 4, a through hole 950 b is formed in the central portion of the coil holding member 950 by utilizing the fact that no coil member is disposed in the central portion of the spiral coil 905, and an earth shield container 10 is provided with a through hole 10a and an observation window portion 10b (for example, formed of a quartz glass material) at a position corresponding to the through hole 950b, the through holes 10a and 950b and the bell jar are provided from the observation window portion 10b. 2, the space in the processing chamber 3 can be visually observed.

(Third embodiment)
Next, a schematic cross-sectional view of a plasma processing apparatus 200 according to the third embodiment of the present invention is shown in FIG. As shown in FIG. 5, the plasma processing apparatus 200 has a substantially flat dielectric window 202 instead of the substantially hemispherical dielectric window 2, and therefore the plasma processing apparatus of the second embodiment. Although the configuration is different from that of the plasma window 100, other configurations not related to the form of the dielectric window 202 are the same as those of the plasma processing apparatus 100. Further, it can be said that the plasma processing apparatus 200 of FIG. 5 has a configuration similar to the plasma processing apparatus 800 of the first embodiment of FIG. 1 in that it has a substantially flat dielectric window 202. However, they have different configurations in that the liquid flow path 220 (liquid container) and the plasma excitation coil 205 are provided inside the dielectric window 202. Hereinafter, this different configuration will be mainly described. In order to facilitate understanding of the description, parts of the plasma processing apparatus 200 having the same configurations as those of the plasma processing apparatus 100 of the second embodiment are denoted by the same reference numerals and description thereof is omitted. It shall be. Further, the plasma processing apparatus 200 includes a control device (corresponding to the control device 90) that performs overall control, as in the plasma processing apparatus 100 of the second embodiment, but has the same configuration. Therefore, the display is omitted in FIG.

  As shown in FIG. 5, the plasma processing apparatus 200 includes a substantially disk-shaped dielectric window 202 that is disposed so as to close the upper opening of the vacuum chamber 1 and is formed of a dielectric material. A space in the vacuum vessel 1 sealed by 202 and in which plasma processing is performed is formed as a processing chamber 203.

  The dielectric window 202 is formed by joining together an upper dielectric plate 202a and a lower dielectric plate 202b, which are two substantially disc-shaped dielectric plates made of the dielectric material. . Further, a continuous groove portion having a substantially concave cross section is formed on the bonding surface of the upper dielectric plate 202a and the lower dielectric plate 202b so that the formation arrangement of the upper dielectric plate 202a and the lower dielectric plate 202b is matched. By joining the plate 202a and the lower dielectric plate 202b, a continuous liquid flow path 220 for the liquid surrounded by the respective concave inner walls through which the cooling / heating medium liquid can flow is formed. Yes. Such a liquid flow path 220 is formed, for example, in a spiral shape around the center from the approximate center of the dielectric window 202. In addition, a supply hole 220a for the cooling / heating medium liquid is formed at the end of the liquid flow path 220 on the center side so as to penetrate the upper dielectric plate 202a, and the spiral flow path of the liquid flow path 220 is formed. The cooling / warming fluid discharge hole 220b is formed at the outer peripheral end so as to penetrate the upper-side dielectric plate 202a. The liquid flow path 220 is also an example of a liquid chamber that can store the cooling / heating medium liquid formed with the inner wall of the groove formed inside the dielectric window 202 as the chamber wall. In the plasma processing apparatus 200 according to the third embodiment, the lower dielectric plate 202b is an example of a dielectric window, and the upper dielectric plate 202a is an example of a liquid container. Since the liquid container is formed of a dielectric material, one dielectric window 202 in which the dielectric window and the liquid container are combined is formed.

  The supply hole 220a and the discharge hole 220b of the liquid flow path 220 are communicated with the upper chiller unit 21 through the flow path 222 which is an example of the liquid flow path. The controlled cooling / heating medium liquid is supplied into the liquid flow path 220 through the flow path 222 and the supply hole 220a, and the cooling / heating medium liquid in the liquid flow path 220 is supplied to the upper side through the discharge hole 220b and the flow path 222. The cold / warm fluid can be circulated so as to be collected in the chiller unit 21.

  In addition, a coil that is an example of a plasma excitation coil that is continuously formed with a conductor wire so as to substantially match the substantially spiral shape inside the substantially spirally formed liquid flow path 220. 205 is arranged. The substantially spiral central end of the coil 205 is connected to a coil high-frequency power source 206 disposed outside the apparatus via a matching unit 218, and the substantially spiral outer peripheral end of the coil 205 is connected to the coil 205. Is connected to a ground terminal outside the apparatus.

  Further, an O-ring 226 is provided at a joint portion between the dielectric window 202 and the vacuum vessel 1 in order to ensure the hermeticity inside the processing chamber 203. Further, in order to securely fix (releasably fix) the dielectric window 202 to the vacuum vessel 1, the dielectric window 202 is fixed to the upper portion of the vacuum vessel 1 by using a holding fitting 228 which is a fixing member at the end thereof. It is fixed to. An earth shield 210 made of a conductive material is attached to the upper portion of the vacuum vessel 1 so as to cover the outer surface of the dielectric window 202 and the space near the surface.

  In the plasma processing apparatus 200 having such a configuration, the operation of performing the plasma processing on the substrate 9 placed on the lower electrode 7 is the same as that of the plasma processing apparatus 800 of the first embodiment and the second embodiment. This is the same as in the case of the plasma processing apparatus 100. Specifically, a cooling medium liquid controlled to a desired temperature is supplied from the supply hole 220a to the liquid flow path 220 formed inside the dielectric window 202 through the passage 222, and the passage from the discharge hole 220b. The dielectric window 202 and the coil 205 can be controlled to a desired temperature by circulating the cooling / heating medium liquid so that the supplied cooling / heating medium liquid is discharged to the liquid flow path 220.

  In addition, the dielectric window 202 having such a liquid flow path 220 in the upper portion of the upper dielectric plate 202a and the lower dielectric plate 202b in which the concave groove portion is formed is aligned with the groove portion. Can be bonded together by bonding them with an adhesive or the like. As such an adhesive, a rubber adhesive that can maintain elasticity even after curing, for example, a thermosetting silicone rubber adhesive can be preferably used. Further, instead of the case where the bonding is performed using the adhesive as described above, each of the bonding is performed after making the flat surface with high accuracy with respect to the bonding surfaces of the upper dielectric plate 202a and the lower dielectric plate 202b. The upper side dielectric plate 202a and the lower side dielectric plate are heated by high-temperature heating in a state where the inside of the liquid flow path 220 is evacuated or pressed from the outside while matching the surfaces and the respective joint surfaces are firmly adhered. 202b can also be bonded at high temperature atoms.

  According to the third embodiment, when the dielectric window 202 has a substantially flat plate shape, the liquid flow path 220 is formed in the dielectric window 202, and the coil 205 is formed in the liquid flow path 220. By disposing the refrigeration medium liquid controlled to a desired temperature in the liquid flow path 220, the surfaces of the dielectric window 202 and the coil 205 can be controlled to a desired temperature. The same effect as the embodiment can be obtained.

  By disposing the coil 205 in the liquid flow path 220 formed inside the dielectric window 202 in this way, the distance between the coil 205 and the lower surface of the dielectric window 202 (the upper surface inner wall of the processing chamber 203) can be reduced. The temperature can be shortened, and reliable temperature control of the dielectric window 202 and the coil 205 can be achieved while obtaining a higher plasma excitation force.

  Further, even when the dielectric window 202 has a substantially flat plate shape and is formed thick in order to obtain a strength capable of withstanding atmospheric pressure, the liquid flow path (liquid chamber) 220 is used. Can be disposed at a position close to the processing chamber side surface of the dielectric window 202 and the coil 205, and the dielectric window surface can be reliably cooled.

  Further, in the plasma processing apparatus 200 of the third embodiment, since the liquid flow path 220 is formed in a substantially spiral shape inside the dielectric window 202, the surface area for heat conduction can be made relatively large. There is an advantage that the temperature controllability can be improved. Furthermore, there is an advantage that the amount of the cooling / heating medium liquid can be reduced, and the cost of the apparatus can be reduced, the size can be reduced, and the temperature control power can be saved.

(Fourth embodiment)
Next, the schematic cross section of the plasma processing apparatus 300 concerning the 4th Embodiment of this invention is shown in FIG. In the following description, the same reference numerals are given to the same components as those of the plasma processing apparatus 100 of the second embodiment, and the description thereof will be omitted.

  As shown in FIG. 6, the plasma processing apparatus 300 is a liquid formed above the substantially hemispherical or dome-shaped bell jar 2 and surrounded by the outer surface of the bell jar 2 and the inner surface of the earth shield container 310. Although it has a configuration similar to that of the plasma processing apparatus 100 of the second embodiment in that the chamber 320 is provided, the cold / warm fluid contained in the liquid chamber 320 is not circulated through the chiller unit 325. However, the configuration is different from that of the second embodiment. Hereinafter, this different configuration will be mainly described.

  As shown in FIG. 6, the liquid chamber 320 is configured to communicate with the outside of the apparatus (that is, in the atmosphere) via a reserve tank 330 formed in the upper portion thereof. Contains liquid. The reserve tank 330 has a role for absorbing and adjusting the volume change (or slight evaporation) accompanying the temperature change of the cooling / heating medium liquid accommodated in the liquid chamber 320.

  Further, an outer peripheral side cooling / heating medium liquid flow path 331 is formed around the liquid chamber 320, that is, on the outer peripheral portion of the earth shield container 310 so as to surround the liquid chamber 320. In addition, in this outer peripheral side cold / warm fluid channel 331, the temperature-controlled secondary cold / warm fluid (which is an example of a fluid that is separable from the cold / warm fluid) is circulated therein. It is possible to cool or heat the cooling medium liquid stored in the adjacent liquid chamber 320, which is an example of a heat exchanger unit. In addition, a supply hole 331a and a discharge hole 331b for discharging the secondary cooling / heating medium liquid are formed in the outer peripheral side cooling / heating medium liquid flow path 331, and the supply hole 331a is provided with the cooling / heating medium liquid flow path. The liquid channel 23 communicates with the liquid channel 23 of the lower electrode 7 through the channel 322, and the liquid channel 23 communicates with the chiller unit 325 through the cold medium liquid channel 24. On the other hand, the discharge hole 331 b communicates with the chiller unit 325 through the cold / warm fluid channel 332.

  By being configured in this way, the secondary cooling / heating medium liquid controlled to a desired temperature by the chiller unit 325 is circulated through the liquid flow path 23 of the lower electrode 7 through the cooling / heating medium liquid passage 24, The temperature of the electrode 7 can be controlled. Further, the secondary cooling / heating medium liquid is supplied from the liquid flow path 23 of the lower electrode 7 into the outer peripheral side cooling / heating medium liquid flow path 331 through the cooling / heating medium liquid passage 322 and the supply hole 331a, and the supplied secondary is supplied. By circulating the cooling / heating medium liquid so as to return to the chiller unit 325 through the discharge hole 331b and the cooling / heating medium liquid flow path 332, the cooling / heating medium liquid stored in the liquid chamber 320 can be controlled to a desired temperature. It has become.

  Furthermore, the earth shield container 310 is provided with a stirrer 333 that stirs the cold / warm medium liquid accommodated in the liquid chamber 320, and the temperature of the cold / warm medium liquid accommodated in the liquid chamber 320 is uniform. Can be achieved. Therefore, it is possible to control the surface temperature of the bell jar 2 and the coil 5 using the cooling / heating medium liquid that is made uniform and whose temperature is controlled.

  In addition, as the cooling / heating medium liquid stored in the liquid chamber 320, considering that it is in direct contact with the coil 5, a fluorine-based oil or silicon having electrical insulation properties as in the first embodiment. On the other hand, since the secondary cooling / heating medium liquid circulated in the outer circumferential side cooling / heating medium liquid flow path 331 does not come into contact with the coil 5, it has electrical insulation. A liquid that is generally used as a cooling / heating medium, such as tap water or ethylene glycol, can be used.

  In the fourth embodiment, a chiller unit 325 including a refrigerator (cooling device) and a heater (heating device) is an example of a liquid temperature adjusting device. It is possible to indirectly adjust the temperature of the cooling / heating medium liquid accommodated in the chamber 320.

  According to the fourth embodiment, in addition to the effects of the second embodiment, the secondary cooling / heating medium liquid whose temperature is directly controlled by the chiller unit 325 is further contained in the liquid chamber 320. Since the temperature control of the above-described cooling / heating medium liquid can be indirectly performed and the temperature control of the bell jar 2 and the coil 5 can be performed, a relatively expensive fluorine-based or silicon-based oil and a chiller unit for the oil are used. In addition, the relatively inexpensive water or ethylene glycol generally used and the chiller unit 325 for these fluids can be used, and the cost of the plasma processing apparatus 300 can be suppressed.

  Further, since the liquid chamber 320 is provided with the stirrer 333, heat exchange with the secondary cooling / heating medium liquid in the flow path 331 is promoted and the temperature of the cooling / heating medium liquid in the liquid chamber 333 is made uniform. Therefore, the controllability of the temperature of the bell jar 2 and the coil 5 can be improved.

(Fifth embodiment)
Next, the schematic cross section of the plasma processing apparatus 400 concerning the 5th Embodiment of this invention is shown in FIG. As shown in FIG. 7, the plasma processing apparatus 400 is different in the configuration for heating or cooling the cooling / heating medium liquid stored in the liquid chamber 420 formed by being surrounded by the bell jar 2 and the earth shield container 410. Except for this point, the configuration is the same as that of the plasma processing apparatus 300 of the fourth embodiment. Only this different configuration will be described below.

  As shown in FIG. 7, a large number of cooling fins 410 a are formed on the substantially cylindrical outer peripheral side wall of the earth shield container 410 in the plasma processing apparatus 400, and this cooling fin is provided outside the earth shield container 410. A cooling fan 440 that sends air to the fins 410a is provided. In the fourth embodiment, the cooling fins 410a and the cooling fan 440 are an example of an air cooling device.

  Further, the inside of the earth shield container 410, that is, the liquid chamber 420 is provided with a heater 441 and a stirrer 333 for heating the cold / warm medium liquid stored in the liquid chamber 420.

  Thus, with respect to the cooling medium liquid stored in the liquid chamber 420, the cooling fins 410a and the cooling fans 440 are provided as cooling devices, the heater 441 is provided as the heating device, and the temperature of the internal liquid is uniform. By providing the stirrer 333 for conversion, the temperature of the cooling / heating medium liquid can be controlled to a desired temperature while controlling the cooling device and the heating device. That is, in the fourth embodiment, the cooling fin 410a, the cooling fan 440, the heater 441, and the stirrer 333 are an example of a liquid temperature adjusting device.

  According to the fifth embodiment, the cooling fin 410a, the cooling fan 440, the heater 441, and the stirrer 333 are configured without using a chiller unit in controlling the temperature of the cooling medium liquid stored in the liquid chamber 420. Therefore, it is possible to contribute to the miniaturization of the apparatus and the simplification of the configuration, the manufacturing cost can be reduced, and the apparatus can be miniaturized.

(Sixth embodiment)
Next, a schematic cross-sectional view showing a schematic configuration of a plasma processing apparatus 700 according to the sixth embodiment of the present invention is shown in FIG. As shown in FIG. 8, the plasma processing apparatus 700 has no external cooling mechanism for the cooling / heating medium liquid housed in the liquid chamber 720 formed surrounded by the bell jar 2 and the earth shield container 710. Except for this point and the configuration of the liquid supply / discharge port, the configuration is similar to that of the plasma processing apparatus 400 of the fifth embodiment. Only this different configuration will be described below.

  As shown in FIG. 8, the plasma processing apparatus 700 includes a liquid chamber 720 formed by being surrounded by the bell jar 2 and the earth shield container 710, and the cooling medium liquid is accommodated in the liquid chamber 720. Yes. Further, a vapor exhaust hole 710a (which is an example of a liquid vapor discharge unit) for discharging the vapor of the cold / warm medium liquid evaporated in the liquid chamber 720 is formed in the upper portion of the earth shield container 710. 710a is connected to an open air or exhaust device (not shown) through a steam exhaust hole 710a. The earth shield container 710 is provided with a cooling / heating medium liquid supply pipe 740 (an example of a supply unit) that supplies the cooling / heating medium liquid into the liquid chamber 720, and is accommodated in the liquid chamber 720. The cold / warm medium liquid can be supplied from the cold / warm medium liquid supply pipe 740 so that the cold / warm medium liquid can maintain a predetermined liquid level. A heater 441 and a stirrer 333 are provided in the liquid chamber 720 in the same manner as the plasma processing apparatus 400.

  As the cooling / heating medium liquid in the liquid chamber 720, an electrically insulating and safe liquid having a boiling point in the vicinity of a desired temperature (adjusted temperature) where the bell jar 2 and the coil 5 are desired to be maintained (adjusted) is selected. For example, when it is desired to keep the desired temperature near 100 ° C., pure water may be used. If the desired temperature is extremely low, liquid nitrogen or liquefied carbon dioxide gas can be used, and if it is near room temperature, a fluorocarbon-based material can be used.

  Since the plasma processing apparatus 700 has such a configuration, the amount of heat from the bell jar 2 and the coil 5 is applied to (or taken away from) the cold medium liquid in contact, and the amount of heat is evaporated. The surface of the bell jar 2 and the coil 5 can be cooled by evaporating the cold medium liquid as the vapor bubble 750 as latent heat. In addition, the vapor | steam of the said cooling / heating medium liquid is discharge | released out of the liquid chamber 720 from the vapor | steam exhaust hole 710a. Further, the storage capacity of the cold / warm fluid reduced by the release of the vapor is compensated by being supplied from the cold / warm fluid supply pipe 740. In addition, in order to supply the cooling / heating medium liquid, the liquid chamber 720 is provided with a sensor (not shown) for detecting the liquid level of the cooling / heating medium liquid.

  In addition, it replaces with the case where the heater 441 is used as a heating apparatus of the said cooling / heating medium liquid in this way, the said cooling / heating temperature accommodated in the liquid chamber 720 by applying a slightly high frequency electric power to the coil 5. The medium liquid can be heated to a desired temperature, and the bell jar 2 can be heated via the cold / temperature medium liquid. On the other hand, when the bell jar 2 is heated to a desired temperature in advance, a heater 441 and a stirrer 333 can be used as in the fifth embodiment.

  According to the sixth embodiment, it is possible to provide a low-cost apparatus that has a sufficient cooling function and can simplify the configuration of the plasma processing apparatus 700.

Incidentally, in the plasma processing apparatus of the above respective embodiments, the coil disposed in the liquid chamber, but all its cold medium liquid supplied to the liquid chamber case has been described as immersed, the The invention is not limited only to such cases. Instead of such a case, it may be a case where only part of the coil is as immersed in cold medium liquid.

The plasma processing apparatus 700 of the sixth embodiment will be described as an example. For example, as shown in FIG. 9, in the liquid chamber 720, the amount of the cold / warm medium liquid is smaller than the state shown in FIG. the liquid level of the cold medium liquid are, even when the part of the coil 5 is exposed, the entire illustrated upper side surface of the bell jar 2 is, if it is immersed in the cold medium liquid, The temperature control for the bell jar 2 having a higher necessity for the temperature control can be reliably performed, and the effect of the sixth embodiment can be obtained. However, from the viewpoint of reliably performed even the temperature control of the coil 5 in addition to the bell jar 2, it is desirable that all of the coil 5 is immersed in the cold medium liquid.

  In each of the above embodiments, the case where the dielectric window and the coil are cooled and heated by the cooling / heating medium liquid has been described. However, the present invention is not limited to such a case, and the plasma is not limited thereto. Even when the dielectric window is cooled only by the cold / warm liquid during the treatment, the present invention can be applied to obtain the effect.

  Furthermore, as the plasma excitation coil or electrode in the various embodiments described above, in the description in the above embodiment, a so-called ICP (inductively coupled plasma) excitation coil (or antenna) has been illustrated and described. Instead, the same effect can be obtained even if an electrode (or antenna) for CCP (capacitive coupling plasma) excitation is installed in the liquid chamber.

  It is to be noted that, by appropriately combining arbitrary embodiments of the various embodiments described above, the effects possessed by them can be produced.

  Although the present invention has been fully described in connection with preferred embodiments with reference to the accompanying drawings, various variations and modifications will be apparent to those skilled in the art. Such changes and modifications are to be understood as being included therein, so long as they do not depart from the scope of the present invention according to the appended claims.

1 is a schematic cross-sectional view of a plasma processing apparatus according to a first embodiment of the present invention. It is a schematic cross section of the plasma processing apparatus concerning 2nd Embodiment of this invention. It is a schematic cross section of the plasma processing apparatus concerning the modification of the said 2nd Embodiment. It is the sectional view on the AA line in the plasma processing apparatus of FIG. It is a schematic cross section of the plasma processing apparatus concerning 3rd Embodiment of this invention. It is a schematic cross section of the plasma processing apparatus concerning 4th Embodiment of this invention. It is a schematic cross section of the plasma processing apparatus concerning 5th Embodiment of this invention. It is a schematic cross section of the plasma processing apparatus concerning 6th Embodiment of this invention. In the plasma processing apparatus of the said 6th Embodiment, it is a schematic cross section of the plasma processing apparatus which shows the state in which a part of coil is exposed from the liquid level of the cooling / heating medium liquid accommodated in the liquid chamber. It is a schematic cross section (partial figure) of the conventional plasma processing apparatus. It is a schematic cross section of the plasma processing apparatus concerning another conventional example.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1,801 Vacuum container 2 Bell jar 3,803 Processing chamber 4 Reaction gas supply hole 5,805 Coil 6,806 High frequency power source for coil 7 Lower electrode 8 High frequency power source for lower electrode 9 Substrate 10,810 Ground shield container 10a, 810a Exhaust hole 10b, 810b Supply hole 13 Vacuum pump 13a Exhaust port 14, 814 Center electrode 15, 815 Insulating bush 16, 816 Application terminal 17, 817 Earth terminal 18, 818 Matching device 19 Matching device 20, 820 Liquid chamber 21, 821 Upper side chiller Unit 21a, 821a Temperature controller 21b, 821b Temperature sensor 22, 822 Passage 23, 823 Liquid passage 24 Passage 25 Lower side chiller units 26, 27, 826, 827 O-ring 90 Controller 100, 800 Plasma processing device R1 Plasma generation region

Claims (3)

In a plasma processing apparatus for applying an electromagnetic field to a reaction gas introduced into a evacuated processing chamber to excite plasma and performing plasma processing on a substrate in the processing chamber,
A vacuum container forming the processing chamber in which the substrate is held and processing is performed on the substrate;
A dielectric window forming part of the vacuum vessel so as to seal the processing chamber;
The dielectric through a window disposed opposite to the processing chamber, a high frequency power is applied, a plasma excitation coil via the dielectric window to impart an electromagnetic field to the interior of the processing chamber,
A gas supply unit for supplying the reaction gas into the processing chamber;
A vacuum exhaust system to keep a constant pressure of the processing chamber is evacuated to the process chamber,
A high frequency power supply for applying a high-frequency power to the plasma excitation coil,
A liquid chamber containing the liquid is contained therein so that the surface of the dielectric window opposite to the surface on the processing chamber side is immersed in an electrically insulating liquid. formed in, and a liquid container for disposing the plasma excitation coil to the liquid chamber,
In the liquid container, the liquid chamber is communicated with the first chamber so that the first chamber to which the electrically insulating liquid is supplied and the liquid supplied to the first chamber can be supplied therein, A liquid chamber partitioning member that divides the surface of the dielectric window on the liquid chamber side and the second chamber in which the plasma excitation coil is disposed;
In the liquid chamber, a support guide member that supports the liquid chamber partition member while guiding the partition position of the first chamber and the second chamber in a variable direction,
Due to the pressure difference between the liquid housed in the first chamber and the liquid housed in the second chamber, the plasma excitation coil is pressed and brought into close contact with the surface of the dielectric window on the liquid chamber side. Plasma processing equipment. In the second chamber of the liquid chamber accommodating container, the gap of the plasma excitation coil wound around the screw spiral is the liquid chamber partitioned member and the liquid flow of the worm spiral surrounded by the above dielectric window The plasma processing apparatus according to claim 1 , wherein a path is formed. In the second chamber of the liquid chamber accommodating container, the upper Kinishi from the center side of the liquid flow path helically toward the outer circumferential side can flow is the electrically insulating liquid, said second chamber from said first chamber The plasma processing apparatus according to claim 2 , wherein a supply position of the liquid to the center is disposed on a center side of the liquid flow path.

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