JP7096080B2 - Plasma processing equipment - Google Patents

Description

The present invention relates to a plasma processing apparatus .

Plasma processing such as plasma etching, plasma CVD (Chemical Vapor Deposition), and plasma ashing is widely used in semiconductor device manufacturing. However, in the semiconductor device manufacturing process, it is important to ensure good processing uniformity while suppressing minute foreign substances and contamination from the viewpoint of ensuring mass productivity. In particular, adhesion of minute foreign matter to the wafer and metal contamination have a serious effect on the device characteristics, so suppression of minute foreign matter and contamination sources is required as a major premise. Further, in order to increase the number of chips obtained per wafer, uniformity of uniform processing on the wafer surface is also required. Further, in order to cope with a semiconductor device having a three-dimensional structure having a more complicated structure, there is also a demand for anisotropic processing in which processing is performed in the direction perpendicular to the wafer surface.

ECR (Electron Cyclotron Resonance), inductively coupled, and capacitive coupling are known as plasma generation methods in a plasma etching apparatus. The ECR method is a plasma generation method that utilizes a resonance phenomenon in which the rotation frequency of electrons rotating around magnetic lines and the microwave frequency match. The ECR method has a feature that the ion flux distribution in the wafer surface can be controlled by changing the ECR plasma generation region by controlling the coil magnetic field used for ECR plasma generation, and the processing uniformity in device manufacturing can be ensured.

Further, in a plasma etching apparatus, in order to realize anisotropic processing during etching while accelerating ions toward a wafer, a high frequency bias power of several hundred kHz to several tens of MHz may be applied to the wafer. be. Generally, an electrode to which a high frequency bias voltage is applied is supplied with power from a high frequency power supply via a blocking capacitor. In order to apply a high voltage bias voltage to the wafer side and allow ions to enter the wafer with high energy, it is necessary to increase the ratio of the ground electrode area to the bias application electrode area.

When the ratio of this area is large, a self-bias voltage of a DC component is applied to the wafer side, ions can be accelerated toward the wafer, and anisotropic processing can be realized. On the other hand, when the ratio of the areas is small, the capacitance in the sheath on the surface of the ground electrode increases, and the capacitive impedance on the surface of the ground electrode increases. In other words, a large voltage drop occurs in the sheath on the surface of the ground electrode, and the voltage drop in the sheath on the surface of the substrate is relatively small. In this case, the ions are accelerated and incident on the surface of the ground electrode rather than the wafer. As a result, the surface of the ground electrode is sputtered by ions, which may cause foreign matter and contamination.

Japanese Unexamined Patent Publication No. 2013-175770 Japanese Unexamined Patent Publication No. 2000-348897

By the way, in order to secure an effective ground electrode area for high frequency bias in the etching apparatus, a ground electrode may be installed above the wafer and on the side surface of the reactor. Generally, high-density plasma is generated above the wafer, so if ground electrodes are installed above the wafer and on the side surface of the reactor, these are sputtered by the high-density plasma, which causes foreign matter and contamination. However, if the ground electrode area above the wafer and on the side surface of the reactor is reduced, the ground electrode area for high frequency bias may be insufficient, and a sufficient bias voltage may not be applied to the substrate.

On the other hand, in order to secure an effective ground electrode area against high frequency bias, there is also a technique of installing a ground electrode made of a non-magnetic material under the stage (see Patent Documents 1 and 2). The effective ground electrode area referred to here refers to the area of the ground electrode surface included in the current path of the high frequency bias.

The techniques described in Patent Documents 1 and 2 are advantageous for expanding the effective ground electrode area for plasma generation methods such as inductively coupled plasma and capacitively coupled plasma in which a magnetic field is not applied from the outside. Is. However, in the case of an etching device to which a static magnetic field is applied, such as a microwave ECR etching device, the effective ground electrode area for high frequency bias does not necessarily expand.

The reason is that in an etching apparatus to which a static magnetic field is applied, the electrons in the plasma are difficult to move in the direction crossing the magnetic field lines and easily move in the direction along the magnetic field lines, so that the electron current due to the high frequency bias is generated. This is because the wafer is directed to the ground electrode along the magnetic field lines through the plasma processing chamber. That is, since the high-frequency bias current path is basically constrained by the direction of the magnetic field lines, if a non-magnetic ground electrode is simply added, the surface area of the ground electrode itself increases, but the direction of the magnetic field lines inside the device changes. Therefore, it is not possible to expect a substantial increase in the ground electrode area for high-frequency bias.

An object of the present invention is to provide a plasma processing apparatus capable of performing anisotropic processing while suppressing foreign matter and contamination on a substrate by securing an effective ground electrode area against high frequency bias in an environment where a static magnetic field is applied. It is to be realized.

In order to solve the above problems, one of the representative plasma processing devices of the present invention is
A processing chamber that is placed inside the vacuum vessel and plasma is formed inside,
A sample table on which the wafer to be processed, which is arranged below the space where the plasma is formed in the processing chamber, is placed on the upper surface, and
A high-frequency power supply that supplies high-frequency power to the electrodes inside the sample table,
It is arranged outside the vacuum vessel so as to surround at least one of the upper side and the side of the processing chamber, and is formed downwardly and divergently around the sample table in order to form plasma in the space inside the vacuum vessel. The magnetic field forming part that forms the created magnetic field and
A grounding member, which is below the upper surface of the sample table in the processing chamber and includes a ring plate made of a magnetic material arranged around the sample table and is maintained at a ground potential, is provided.
The grounding member is composed of a ring plate made of a magnetic material and a ring plate made of a non-magnetic material that covers the upper surface of the ring plate made of the magnetic material.
This is achieved by the clearance between the non-magnetic ring plate and the sample table being smaller than the clearance between the magnetic ring plate and the sample table .

Further, one of the representative plasma processing devices of the present invention is
A processing chamber that is placed inside the vacuum vessel and plasma is formed inside,
A sample table on which the wafer to be processed, which is arranged below the space where the plasma is formed in the processing chamber, is placed on the upper surface, and
A high-frequency power supply that supplies high-frequency power to the electrodes inside the sample table,
It is arranged outside the vacuum vessel so as to surround at least one of the upper side and the side of the processing chamber, and is formed downwardly and divergently around the sample table in order to form plasma in the space inside the vacuum vessel. The magnetic field forming part that forms the created magnetic field and
A grounding member, which is below the upper surface of the sample table in the processing chamber and includes a ring plate made of a magnetic material arranged around the sample table and is maintained at a ground potential, is provided.
This is achieved by the magnetic ring plate penetrating the inner wall of the processing chamber in the grounding member .

According to the present invention, a plasma processing apparatus capable of performing anisotropic processing while suppressing foreign matter and contamination on the substrate by securing an effective ground electrode area against high frequency bias in an environment where a static magnetic field is applied is provided. Can be provided.
Issues, configurations and effects other than those described above will be clarified by the following description of the embodiments.

It is sectional drawing of the etching apparatus which concerns on 1st Embodiment of this invention. It is explanatory drawing which shows the effect of the 1st Embodiment of this invention. It is a simulation figure which shows the effect of the 1st Embodiment of this invention. It is a figure which shows the effect of the 2nd Embodiment of this invention. It is a figure which shows the effect of the 3rd Embodiment of this invention. It is a figure which shows the effect of the 4th Embodiment of this invention. It is a figure which shows the effect of the 5th Embodiment of this invention.

Hereinafter, embodiments of the present invention will be described with reference to the drawings. In the present specification, "downward" in the plasma processing chamber means the direction in which the microwave is directed toward the sample table, and "upper" means the opposite direction.

[First Embodiment]
FIG. 1 shows a cross-sectional view of an etching apparatus which is a plasma processing apparatus according to the first embodiment of the present invention. The microwave oscillated from the microwave source 1 is transmitted to the circular waveguide 6 via the automatic matching machine 3, the isolator 4, and the circular rectangular converter 5 using the rectangular waveguide 2. In the present embodiment, a magnetron that generates a 2.45 GHz microwave, which is often used as an industrial frequency, is used as the microwave source 1. However, the microwave generated from the microwave source 1 is not limited to this frequency, and an electromagnetic wave of several tens of MHz to several tens of GHz may be used.

The automatic matching machine 3 has a role of adjusting the load impedance, suppressing reflected waves, and efficiently supplying electromagnetic waves. Further, an isolator 4 is used to protect the microwave source 1 from the reflected wave. For the circular waveguide 6, a tube having a diameter that propagates microwaves corresponding only to the circular TE11 mode, which is the basic mode, is selected. The reason is that when a higher-order mode is included, the stability and uniformity of plasma generation may be adversely affected. The circular waveguide 6 is connected to the cavity 7, and the cavity 7 has a function of adjusting the electromagnetic field distribution to a distribution suitable for plasma processing.

A microwave introduction window 8, a shower plate 9, and an inner cylinder 10 are provided in the lower portion of the cavity 7. The material of the microwave introduction window 8 and the shower plate 9 is preferably quartz, which efficiently transmits microwaves and has plasma resistance. Alternatively, as these materials, for example, yttrium, alumina, yttrium fluoride, aluminum fluoride, aluminum nitride, etc., which have high plasma resistance and transmit microwaves, may be used.

The inner cylinder 10 does not necessarily have to transmit microwaves, but must have plasma resistance from the viewpoint of suppressing foreign matter and contamination on the wafer due to sputtering of the inner cylinder and the like. For example, the material of the inner cylinder 10 is quartz, but yttrium, alumina, yttrium fluoride, aluminum fluoride, aluminum nitride and the like may be used.

Gas is supplied into the inner cylinder 10 from the external gas supply means 11 by passing between the microwave introduction window 8 and the shower plate 9. The gas supply means 11 includes a function of supplying a desired flow rate by, for example, a mass flow controller (not shown). The shower plate 9 is provided with a plurality of fine gas supply holes, and the processing gas supplied from the gas supply means 11 can be uniformly supplied to the plasma processing chamber 100 in a shower shape.

An insulating plate 14 is provided below the substrate stage and high frequency electrode (sample table) 13 on which the substrate 12 to be processed, which is a wafer, is placed, and the processing gas supplied from the gas supply means 11 is a conductance adjusting valve 15. It is configured to be evacuated by the turbo molecular pump 16 via the above. Further, in order to supply bias power to the substrate 12 to be processed, a bias power supply (high frequency power supply) 18 is connected to the substrate stage and high frequency electrode 13 via an automatic bias matching machine 17.

In this embodiment, the frequency of the bias power supply 18 is 400 kHz, but a bias power supply having a frequency other than that may be used according to the purpose required for plasma processing, for example, the industrial frequency of 13.56 MHz. good. Further, the substrate stage and high frequency electrode 13 is provided with a temperature controlling means (not shown), and the temperature of the substrate 12 to be processed is adjusted as necessary so that desired etching can be performed.

A susceptor 19 made of a dielectric and a covering 20 are installed on the outer peripheral portion and the side surface of the upper surface of the substrate stage / high frequency electrode 13 to protect the substrate stage / high frequency electrode 13. For example, as the material of the susceptor 19 and the covering 20, quartz can be used as a material having high plasma resistance, but other materials having high plasma resistance such as itria, alumina, yttrium fluoride, and aluminum fluoride. , Aluminum nitride or the like may be used.

Below the plasma processing chamber 100, a chamber inner wall 21 made of a non-magnetic material is provided on the ground so as to be connected to the lower end of the inner cylinder 10, and surrounds a substrate stage and a high frequency electrode 13 and the like. Further, below the upper surface of the substrate stage and high frequency electrode 13, the magnetic grounding electrode (grounding member) 22 is installed so as to extend horizontally from the inner circumference of the chamber inner wall 21. The magnetic ground electrode 22 is maintained at the ground potential via the chamber inner wall 21.

Pure iron can be used as the material of the magnetic ground electrode 22, but permalloy, silicon iron, Fe-Si-Al alloy, ferrite, Co-based amorphous, and Fe-based amorphous, which are soft magnetic materials, are used. Is also good. Further, the magnetic ground electrode 22 is provided with a plurality of holes having a diameter of about 10 mm so that gas does not stay there.

It is desirable to use a soft magnetic material as the material of the magnetic ground electrode 22 which has the property as a magnet in the presence of an external magnetic field and loses the property as a magnet when the external magnetic field is removed. The reason is that hard magnetic materials such as permanent magnets are difficult to use because they are demagnetized due to aging and temperature changes and their magnetic properties change. In particular, since the magnetic ground electrode 22 is exposed to heat input from plasma, the temperature changes frequently, and there is a high possibility that the magnetic properties of the hard magnetic material will change over time. In other words, if a hard magnetic material is used for the magnetic ground electrode 22 at the time of mass production of the device, the processing dimensions after etching may fluctuate with time, and the yield may deteriorate.

Further, in order to prevent corrosion of pure iron used for the magnetic ground electrode 22, for example, it is preferable to coat an alloy such as Ni-Al or Ni-Cr as a corrosion-resistant alloy by about 100 μm. Further, if metal atoms such as iron used in the magnetic ground electrode 22 are emitted to the plasma processing chamber 100 by sputtering or the like and enter the substrate 12 to be processed, there is a possibility that the electrical characteristics of the semiconductor device will be seriously affected. be. Therefore, it is preferable to cover the surface of the magnetic ground electrode 22 with a plasma-resistant film so as not to be a source of metal contamination. For example, in order to improve the plasma resistance of the magnetic ground electrode 22, itria can be coated with 100 μm, but materials with high plasma resistance such as alumina, yttrium fluoride, aluminum fluoride, and aluminum nitride are coated. May be.

The high frequency bias current flows to the magnetic ground electrode 22 via the plasma 101, the sheath on the surface of the magnetic ground electrode 22, and the coating film on the surface of the magnetic ground electrode 22. In order to ensure that the magnetic ground electrode 22 coated with such a plasma resistant film functions as a ground electrode against high frequency bias, the impedance Z _sh of the sheath on the surface of the magnetic ground electrode 22 is compared with that of the magnetic ground electrode 22. Therefore, it is desirable to make the impedance Z _c of the coating film sufficiently small. In this embodiment, Z _c / Z _sh ≦ 5% is set as an index that the impedance Z _c of the coating film is sufficiently small. At this time, the conditions required for the coating film are described below. First, the impedance Z _c of the coating film is expressed by the following equation (Equation 1 equation).

In the equation 1, R _c represents the resistance of the coating film, C _c represents the capacitance of the coating film, and ω represents the angular frequency of the high frequency bias. At this time, since the plasma-resistant coating film is assumed to be an insulator, | R _c | is sufficiently larger than | jωC _c |. Therefore, the resistance component can be ignored. The capacitance C _c of the coating film can be expressed by the following equation (equation 2 equation).

In Equation 2, the substantial ground electrode area for high-frequency bias was S, the relative permittivity of the coating film was ε _c , the permittivity of vacuum was ε ₀ , and the coating film thickness was _dc . Next, the impedance of the sheath on the magnetic ground electrode 22 is calculated. Since the impedance of the sheath is capacitive, it is expressed by the following equation (Equation 3 equation).

In the equation (3), the capacitance _Csh of the sheath on the surface of the magnetic ground electrode 22 is expressed by the following equation (the equation (4)).

Here, it is assumed that the sheath is a layer of vacuum with a thickness of d _sh . The thickness of the sheath is typically 1 × 10 ^-3 m. Based on the above, the thickness of the coating film may be set so as to satisfy the following equation (equation 5 equations) from the constraint condition of Zc / Zsh ≦ 5%.

For example, in an itria having a relative permittivity ε _c of 11.4, the coating film thickness may be 570 μm or less based on the equation 5.

An electromagnetic coil (magnetic field forming portion) 23 is provided around (and at least one of the upper portions) of the plasma processing chamber 100 (inner cylinder 10), and a yoke 24 is provided on the outer periphery thereof. By supplying a current to the electromagnetic coil 23, the static magnetic field distribution is adjusted in the plasma processing chamber 100 so as to satisfy the magnetic flux density required for ECR. The yoke 24 has a role of a magnetic shield that prevents the leakage of the magnetic field to the outside of the device.

The magnetic field lines formed by the electromagnetic coil 23 and the yoke 24 become a diffusion magnetic field that spreads in the outer peripheral direction from above to below in the plasma processing chamber 100 (spreads toward the periphery of the substrate stage and high frequency electrode 13). When projecting 2.45 GHz microwaves, the magnetic flux density required for ECR is 875 G. By adjusting the static magnetic field distribution and adjusting the isomagnetic field surface of 875G to an arbitrary place in the plasma processing chamber 100, the position of the plasma generation region can be adjusted. Further, by adjusting the static magnetic field, it is possible to control the diffusion of plasma to the substrate 12 to be processed. Therefore, it is desirable to use a plurality of electromagnetic coils 23 in order to facilitate control of the plasma generation region and plasma diffusion. Etching is performed by converting the gas introduced into the plasma processing chamber 100 into plasma by the microwave supplied from the microwave source 1 to generate plasma 101, and irradiating the substrate 12 to be processed with the ions and radicals generated there.

Next, the effect caused by the magnetic material grounding electrode 22 being a magnetic material will be described. FIG. 2 is an enlarged cross-sectional view showing the structure around the magnetic ground electrode 22. First, FIG. 2A shows a schematic diagram of magnetic field lines when the magnetic ground electrode 22 is a non-magnetic material. The magnetic field line 102 formed by the electromagnetic coil 23 and the yoke 24 is a diffusion magnetic field that spreads in the outer peripheral direction toward the lower part of the process processing chamber. When the magnetic grounding electrode 22 is a non-magnetic material, as shown in FIG. 2A, the direction of the magnetic field line 102 does not change even if the magnetic grounding electrode 22 is installed, as compared with the case where there is no grounding electrode.

On the other hand, FIG. 2B shows a schematic diagram of the magnetic field lines 102 when the magnetic ground electrode 22 is a soft magnetic material. The soft magnetic material has a high magnetic permeability and has the property of easily passing magnetic lines of force. Therefore, the magnetic field in the plasma processing chamber 100 is basically a diffused magnetic field, but as shown in FIG. 2A, the magnetic field lines 102 are directed toward the magnetic material grounding electrode 22 in the vicinity of the magnetic material grounding electrode 22. Can be bent like.

The bias current flows from the substrate stage / high frequency electrode 13 to the chamber inner wall 21 and the magnetic ground electrode 22. FIG. 3 shows the results of simulating the bias current path (streamline) CF when high-frequency power is supplied to the substrate stage and high-frequency electrode 13 when plasma is generated by the ECR method.

First, FIG. 3A shows a simulation result when the magnetic ground electrode 22 is a non-magnetic material. Since the lines of magnetic force spread in the outer peripheral direction below the device, the bias current path at this time also spreads in the outer peripheral direction below the device depending on the direction of the lines of magnetic force. At this time, it can be seen that the bias current is localized above the inner wall 21 of the chamber. That is, the effective ground electrode area is the area of the region where the bias current flows above the inner wall 21 of the chamber.

Next, FIG. 3B shows a simulation result of the magnetic field line density when the magnetic ground electrode 22 is a soft magnetic material. Since the magnetic field lines are bent in the vicinity of the magnetic material grounding electrode 22 toward the magnetic material grounding electrode 22, it can be seen that the bias current flows not only above the chamber inner wall 21 but also through the magnetic material grounding electrode 22. That is, since the magnetic ground electrode 22 is a magnetic material, the area where the bias current flows is expanded, in other words, the area of the ground electrode effective for high frequency bias is expanded. This is an effect that appears when the ground electrode is made of a magnetic material in a plasma etching apparatus that applies a magnetic field from the outside.

As shown in FIG. 1, it is desirable that a clearance Δ is provided between the magnetic grounding electrode 22 and the substrate stage / high frequency electrode 13. The inner peripheral end and the outer peripheral end of the magnetic grounding electrode 22 are magnetic poles, and the magnetic field lines are particularly concentrated around the magnetic poles, so that the bias current easily flows. However, when there is no gap Δ between the magnetic material grounding electrode 22 and the substrate stage / high frequency electrode 13, the substrate stage / substrate stage / high frequency electrode 13 becomes a physical obstacle in the vicinity of the magnetic pole at the inner peripheral end of the magnetic material grounding electrode 22 which becomes the magnetic pole. Since the high frequency electrode 13 and the covering 20 are present, the bias current cannot be effectively passed through the magnetic ground electrode 22. Therefore, it is desirable to provide a clearance Δ between the magnetic grounding electrode 22 and the substrate stage / high frequency electrode 13 to eliminate physical obstacles in the vicinity of the magnetic poles in the inner peripheral portion of the magnetic grounding electrode 22.

[Second embodiment]
A second embodiment of the present invention is shown in FIG. The magnetic grounding electrode 22 made of a magnetic material has a tapered structure in which the grounding electrode 22 of the magnetic material is inclined downward from the inner circumference of the inner wall 21 of the chamber toward the center. As described above, since the magnetic field is concentrated around the magnetic pole at the inner peripheral end of the magnetic ground electrode 22, the bias current flowing through the magnetic ground electrode 22 may be localized around the magnetic pole in some cases. Sputtering of the magnetic ground electrode 22 may occur in the region where the bias current is localized. Therefore, as in the present embodiment, the risk of foreign matter generation due to sputtering can be reduced by installing the ground electrode so that the inner peripheral end of the ground electrode where the magnetic field is concentrated is located below. Since the other configurations are the same as those of the above-described embodiment, duplicate description will be omitted.

[Third embodiment]
A third embodiment of the present invention is shown in FIG. In the present embodiment, the magnetic ground electrode 22 penetrates the inner wall of the chamber inner wall 21 and extends in the outer peripheral direction. This effect will be described below. When a magnetic field is applied by the electromagnetic coil 23, magnetic poles are generated near the outer peripheral end and the inner peripheral end of the magnetic ground electrode 22. The magnetic flux lines tend to concentrate on the surface around the magnetic poles, but the magnetic flux density becomes almost zero near the middle of the magnetic poles at the outer peripheral end and the inner peripheral end. Since the bias current tends to flow along the magnetic field lines, it becomes difficult for the bias current to flow in the region between the magnetic poles having a small magnetic flux density. That is, in order to efficiently pass the bias current through the magnetic grounding electrode 22, the magnetic grounding electrode 22 may be installed so that only the peripheral portion of the magnetic pole enters the plasma processing chamber 100 as in the present embodiment. .. Since the other configurations are the same as those of the above-described embodiment, duplicate description will be omitted.

[Fourth Embodiment]
A fourth embodiment of the present invention is shown in FIG. FIG. 6 shows a ring above the magnetic ground electrode 22, preferably below the substrate stage / high frequency electrode 13, around the substrate stage / high frequency electrode 13, and not in contact with the outer periphery of the substrate stage / high frequency electrode 13. This is a configuration in which a plate-shaped non-magnetic ground electrode 25 is installed. In the present embodiment, the magnetic grounding electrode 22 and the non-magnetic grounding electrode 25 constitute a grounding member. As described above, the magnetic field lines tend to concentrate around the magnetic poles at the inner peripheral end of the magnetic ground electrode 22. Therefore, if there is no non-magnetic ground electrode 25, the bias current may be localized around the magnetic pole.

On the other hand, by installing the non-magnetic ground electrode 25 so as to obstruct the bias current path toward the magnetic ground electrode 22 as in the configuration of FIG. 6, the bias current is suppressed from flowing locally. Therefore, the area where the bias current flows can be efficiently expanded. Further, in order to more effectively expand the area where the bias current flows, it is desirable that the inner diameter of the non-magnetic ground electrode 25 is smaller than the inner diameter of the magnetic ground electrode 22. That is, the clearance between the substrate stage / high frequency electrode 13 and the non-magnetic ground electrode 25 may be smaller than the clearance between the substrate stage / high frequency electrode 13 and the magnetic ground electrode 22. Further, the non-magnetic ground electrode 25 and the magnetic ground electrode 22 may be configured separately or integrally. For example, the magnetic material grounding electrode 22 may be embedded inside the non-magnetic material grounding electrode 25. Since the other configurations are the same as those of the above-described embodiment, duplicate description will be omitted.

[Fifth Embodiment]
A fifth embodiment according to the present invention is shown in FIG. In order to increase the surface area of the magnetic ground electrode 22, the magnetic ground electrode 22 is not flat but has a wave shape having periodic irregularities in the radial direction. Further, in order to increase the surface area of the magnetic ground electrode 22, a plurality of protrusions may be provided on a flat plate or a corrugated plate. Further, the shape is not limited to the above-mentioned shape, and the shape may be appropriately changed in order to increase the surface area of the magnetic ground electrode. Since the other configurations are the same as those of the above-described embodiment, duplicate description will be omitted.

The present invention is not limited to the above-described embodiment, and includes various modifications. For example, the above-described embodiments have been described in detail in order to explain the present invention in an easy-to-understand manner, and are not necessarily limited to those having all the described configurations. Further, it is possible to replace a part of the configuration in one embodiment with the configuration of another embodiment, and it is also possible to add the configuration of another embodiment to the configuration of one embodiment. .. Further, it is also possible to add / delete / replace a part of the configuration in each embodiment with another configuration.

The present invention is applicable to a plasma processing apparatus that processes a sample on a substrate such as a semiconductor wafer by etching or the like.

1 Microwave source 2 Square waveguide 3 Automatic matching machine 4 Isolator 5 Circular rectangular converter 6 Circular waveguide 7 Cavity 8 Microwave introduction window 9 Shower plate 10 Inner cylinder 11 Gas supply means 12 Processed substrate 13 Substrate stage and High frequency electrode 14 Insulation plate 15 Conductance adjustment valve 16 Turbo molecular pump 17 Bias automatic matching machine 18 Bias power supply 19 Suceptor 20 Covering 21 Chamber inner wall 22 Magnetic ground electrode 23 Electromagnetic coil 24 York 25 Non-magnetic ground electrode 100 Plasma processing chamber 101 Plasma 102 Magnetic lines

Claims (9)

A processing chamber that is placed inside the vacuum vessel and plasma is formed inside,
A sample table on which the wafer to be processed, which is arranged below the space where the plasma is formed in the processing chamber, is placed on the upper surface, and
A high-frequency power supply that supplies high-frequency power to the electrodes inside the sample table,
It is arranged outside the vacuum vessel so as to surround at least one of the upper side and the side of the processing chamber, and is formed downwardly and divergently around the sample table in order to form plasma in the space inside the vacuum vessel. The magnetic field forming part that forms the created magnetic field and
A grounding member, which is below the upper surface of the sample table in the processing chamber and includes a ring plate made of a magnetic material arranged around the sample table and is maintained at a ground potential, is provided.
The grounding member is composed of a ring plate made of a magnetic material and a ring plate made of a non-magnetic material that covers the upper surface of the ring plate made of the magnetic material.
The clearance between the non-magnetic ring plate and the sample table is smaller than the clearance between the magnetic ring plate and the sample table.
A plasma processing device characterized by this. A processing chamber that is placed inside the vacuum vessel and plasma is formed inside,
A sample table on which the wafer to be processed, which is arranged below the space where the plasma is formed in the processing chamber, is placed on the upper surface, and
A high-frequency power supply that supplies high-frequency power to the electrodes inside the sample table,
It is arranged outside the vacuum vessel so as to surround at least one of the upper side and the side of the processing chamber, and is formed downwardly and divergently around the sample table in order to form plasma in the space inside the vacuum vessel. The magnetic field forming part that forms the created magnetic field and
A grounding member, which is below the upper surface of the sample table in the processing chamber and includes a ring plate made of a magnetic material arranged around the sample table and is maintained at a ground potential, is provided.
In the grounding member, the magnetic ring plate penetrates the inner side wall of the processing chamber.
A plasma processing device characterized by this. The plasma processing apparatus according to claim 1 or 2 .
The grounding member was arranged with a gap from the sample table.
A plasma processing device characterized by this. The plasma processing apparatus according to any one of claims 1 to 3 .
The plasma is formed by the electric field of microwaves supplied to the processing chamber and the magnetic field.
A plasma processing device characterized by this. The plasma processing apparatus according to any one of claims 1 to 4 .
In the grounding member, the outer peripheral end of the magnetic ring plate is located on the inner circumference of the inner side wall of the processing chamber.
A plasma processing device characterized by this. The plasma processing apparatus according to any one of claims 1 to 5 .
In the grounding member, the magnetic ring plate has a tapered shape inclined toward the lower center of the processing chamber.
A plasma processing device characterized by this. The plasma processing apparatus according to any one of claims 1 to 6 .
In the grounding member, the ring plate made of the magnetic material has a corrugated shape.
A plasma processing device characterized by this. The plasma processing apparatus according to any one of claims 1 to 7 .
The main component of the material of the ring plate made of a magnetic material is any of permalloy, pure iron, silicon iron, Fe-Si-Al alloy, ferrite, Co-based amorphous, and Fe-based amorphous.
A plasma processing device characterized by this. The plasma processing apparatus according to any one of claims 1 to 8 .
The surface of the magnetic ring plate is coated.
A plasma processing device characterized by this.

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