JP4544265B2 - Shower head structure and film forming apparatus - Google Patents

Description

The present invention relates to a shower head structure used in thin film deposition apparatus and which performs for example a film forming process or heat treatment of the etching process or the like such as a metal oxide film.

  In general, a semiconductor device is manufactured by repeatedly performing a film forming process and a pattern etching process on a semiconductor wafer to manufacture a desired device. Especially, a film forming technique is associated with an increase in density and integration of semiconductor devices. The specifications are becoming stricter year by year. For example, a very thin oxide film such as a capacitor insulating film or a gate insulating film in a device is required to be further thinned. Is required.

As these insulating films, a silicon oxide film, a silicon nitride film, or the like can be used. Recently, metal oxide films such as tantalum oxide (Ta ₂ O ₅₎ have been used as materials having better insulating characteristics. ) Etc. tend to be used (for example, JP-A-2-28302). Even if this metal oxide film is thin as an oxide film equivalent film, it exhibits highly reliable insulation. In order to form a metal oxide film having such good characteristics, it is desired to accurately control the temperature of the semiconductor wafer during film formation.

For example, a case where a tantalum oxide film is formed will be described as an example for forming this metal oxide film. First, a semiconductor wafer is carried into a film forming apparatus and a film forming film is disclosed as disclosed in the above publication. Tantalum metal alkoxide (Ta (OC ₂ H ₅ ) ₅ ) is used as a raw material, and this is supplied while bubbling with nitrogen gas or the like to maintain the semiconductor wafer at a process temperature of about 450 ° C., for example, under a vacuum atmosphere. A tantalum oxide film (Ta ₂ O ₅ ) is laminated by CVD (Chemical Vapor Deposition).
In this case, in order to perform temperature management, in the conventional apparatus, a thermocouple is provided as a temperature detecting means on the mounting table (susceptor) on which the wafer is mounted, and the detected temperature is detected indirectly by detecting the temperature of the wafer. Based on the above, the output of a heating means such as a heating lamp or a heater is controlled to control the wafer temperature.

By the way, this type of thermocouple directly detects the temperature of the mounting table and indirectly determines the temperature of the wafer mounted thereon as described above. It was inevitable that a certain temperature difference occurred between the temperature and the detected temperature.
Therefore, instead of the thermocouple, the wafer temperature is measured by using a radiation thermometer that measures the temperature of the measurement object from the radiance of the specific wavelength band of the measurement object, for example, Japanese Patent Application Laid-Open No. 8-264472 (patent) Reference 1), Japanese Patent Laid-Open No. 11-45859 (Patent Document 2), and the like. This radiation thermometer has the advantage that the wafer temperature can be directly and accurately measured and detected without contact.

JP-A-8-264472 (page 4-5, FIGS. 1 and 2) Japanese Patent Laid-Open No. 11-45859 (page 4, FIG. 1)

  By the way, when this radiation thermometer is used, if an excessive thin film adheres to the incident surface of the photo detector for taking in light from the wafer, the light is absorbed by the thin film and the accurate wafer temperature cannot be measured. An inert gas such as nitrogen gas is applied from the processing space side to the incident surface of the photodetector exposed to the processing space during the film forming process on the wafer, or to a transparent glass substrate that partitions the incident surface and the processing space. The thin film was prevented from adhering to the incident surface and the transparent glass substrate surface by spraying.

However, in this case, as described above, an inert gas is supplied only for the purpose of preventing the adhesion of an excessive thin film to the processing space, so that a metal oxide film is formed for the excessive inert gas. As a result, the partial pressure of the source gas (for example, pentoethoxytantalum) required for the operation is lowered, and as a result, the film thickness of the portion supplied with the inert gas is changed, and the film thickness uniformity in the wafer surface is deteriorated. There was a problem such as.
Also, in a processing apparatus that employs a heating means using a heating lamp, part of the heat rays emitted from the heating lamp are diffusely reflected in the processing vessel, and this heat rays finally enters the radiation thermometer. In this case, there is a problem that the wafer temperature cannot be measured accurately.

The present invention has been devised to pay attention to the above problems and to effectively solve them.
An object of the present invention is to provide a shower head structure and a film forming apparatus capable of improving the in-plane uniformity of film thickness even when a radiation thermometer is used.
The object of the present onset light of the related art, except the influence of irregular reflection of heat rays from the heating lamps, is to provide a thin film deposition apparatus that can measure accurately the temperature of the object to be processed.

According to the first aspect of the present invention, a plurality of first gas injection holes for injecting a raw material gas into a processing space containing the heated object to be processed in order to perform a film forming process on the object to be processed When provided with a plurality of second gas injection hole for injecting an assist gas, at least one of the second gas injection hole, the light introducing rod is provided with kick set by inserting the light introducing rod of the radiation thermometer The opening area of the second gas injection hole is larger than the opening area of the other gas injection hole through which the same type of gas as the gas injected from the other second gas injection hole is injected. a shower head structure, characterized in that it has by Uni configuration is only set larger area corresponding to the area.
As described above, since the light introduction rod of the radiation thermometer is inserted into the gas injection hole of the shower head structure, the light introduction rod is covered with, for example, the processing gas injected during the film forming process. Thus, it is possible to prevent the thin film from adhering to the light introduction surface. Therefore, the temperature of the object to be processed can always be accurately measured and detected.
In addition, since no special gas such as an inert gas is used to prevent thin film adhesion, the partial pressure of the source gas is not partially disturbed, and the in-plane uniformity of processing such as film formation is improved. Can be made.
Further, the gas injection amount from the gas injection hole through which the light introducing rod is inserted is substantially the same as the gas injection amount injected from the other same kind of gas injection hole, so that the gas flow rate may be disturbed. In addition, the in-plane uniformity of the processing such as the film thickness can be further improved than this point.

In this case, for example, as defined in claim 2, the light introduction rod is located at a substantial center of the gas ejection surface.
Alternatively, for example, as defined in claim 3, a plurality of the light introduction rods may be provided along the radial direction including the substantial center portion of the gas injection surface .

Further, for example, as specified in請Motomeko 4, wherein the light introducing rod is vertically movably provided to be connected to the rod lifting mechanism so that it can be retracted when required.
According to this, for example, when the light introduction rod is not used, if the light introduction rod is retracted and separated from the processing space, the light introduction surface of the light introduction rod is damaged, for example, during cleaning, and the surface becomes rough. It is possible to prevent the occurrence.
Further, for example, as prescribed in claim 5, wherein the light introducing rod, the are inserted through the rod through hole formed in the ceiling plate of the shower head structure, the upper end of the rod through hole, An isolation valve is provided for closing the rod through hole when the light introducing rod is retracted.
According to this, when the light introduction rod is not used, if the light introduction rod is retracted and the isolation valve is closed, the light introduction surface of the light introduction rod can be reliably prevented from being damaged, for example, during cleaning. It becomes possible to do.

For example , as defined in claim 6, the assist gas is an oxidizing gas.
Alternatively, for example , as defined in claim 7, the assist gas is a reducing gas.
According to an eighth aspect of the present invention, there is provided a film forming apparatus for performing a film forming process on an object to be processed, a processing container that can be evacuated, a mounting table on which the object to be processed is mounted, heating means for heating the object to be processed, according to claim 1乃optimum 7 Noi shower head structure described in one paragraph or displacement, the heating means based on the detected value of the radiation thermometer provided in the shower head structure And a temperature control unit that controls the film formation processing apparatus.

To claim 9 Ru engagement invention, the thin film deposition apparatus for performing a film forming process with respect to the workpiece, and a vacuum evacuable processing chamber, a mounting table mounting the object to be processed, a temperature measuring means provided in the mounting table, and a heating means for heating the object to be processed, and a shower head structure according to claim 1乃optimum 7 Neu deviation or claim, deposition of the target object Radiation provided in the shower head structure when a film forming process is performed using a temperature control unit that controls the heating unit based on a detection value of the temperature measuring unit during processing and a temperature calibration target object A film forming process comprising: a temperature calibration control unit that calibrates the set temperature value of the mounting table in the temperature control unit based on a detection value of a thermometer and a target temperature value of the object to be processed Device.

In this case, for example , as defined in claim 10, the temperature measuring means is a thermocouple.
Further, for example , as defined in claim 11, the heating means includes a heating lamp, and the mounting table has a ring shape which is low in thermal conductivity and colored so as to block heat rays from the heating lamp. It is held by a holding member.
According to this, in the heat rays radiated from the heating lamp of the heating means, the heat rays directed to the portion other than the mounting table are finally formed by the colored holding member that holds the peripheral portion of the mounting table even if it is irregularly reflected inside. Therefore, the irregularly reflected heat rays do not leak into the processing space and enter the radiation thermometer, so that the temperature of the object to be processed can be measured with higher accuracy.

The related art of the present invention is a film forming apparatus for performing a film forming process on an object to be processed, a processing container that can be evacuated, a mounting table on which the object to be processed is mounted, A heating unit having a heating lamp that is provided below the mounting table and heats the object to be processed, and is formed of an opaque material that has low thermal conductivity and blocks heat rays from the heating lamp. A ring-shaped holding member that contacts and holds the periphery of the substrate, a first gas injection hole for supplying the source gas, and a second gas injection hole for supplying the assist gas. And a radiation thermometer provided in the shower head structure.
According to this, in the heat rays radiated from the heating lamp of the heating means, the heat rays directed to the portion other than the mounting table are finally formed by the colored holding member that holds the peripheral portion of the mounting table even if it is irregularly reflected inside. Therefore, the irregularly reflected heat rays do not leak into the processing space and enter the radiation thermometer, so that the temperature of the object to be processed can be measured with higher accuracy.
In this case, for example, the holding member is made of quartz containing black metal oxide such as niobium oxide, quartz containing black SiC, quartz containing carbon, black ceramic such as black AlN containing carbon. Consisting of one of the following.
Further, for example, a blocking ring for blocking heat rays is provided on the upper surface of the holding member, and the blocking ring includes quartz containing black metal oxide such as niobium oxide, quartz containing black SiC, and carbon. It is made of any one of black ceramics such as quartz and black AlN containing carbon.

The related art of the present invention includes a processing container that can be evacuated, a mounting table on which the object to be processed is mounted, a heating unit that heats the object to be processed, and a processing container for supplying a processing gas. A shower head structure provided on a ceiling, and a processing device for performing a predetermined process on the object to be processed, a heat ray outlet passage provided so as to penetrate the shower head structure in a vertical direction; A radiation thermometer attached to an upper end opening of the heat ray outlet passage through a measurement window, and an inert gas introduction passage for introducing an inert gas into the heat ray outlet passage, and a lower end of the heat ray outlet passage The position at which the main gas flow of the inert gas flowing out from the opening and diffusing while flowing toward the outside of the mounting table flows down to the same horizontal level as the upper surface of the mounting table is The cover placed on As on the outside than the outer periphery of the physical body is a processing apparatus characterized by being configured the heat ray discharge passage so as to provide by eccentric away from the center of the shower head structure.
According to this, since the main gas flow of the inert gas flowing so that the film does not adhere to the measurement window attached with the radiation thermometer is prevented from coming into contact with the surface of the object to be processed, the object to be processed It is possible to prevent the film deposited on the surface of the film from becoming thin locally.

In this case, the distance between the center of the lower end opening of the center and the heat ray discharge passage prior Symbol shower head structure if example embodiment, the is set to a distance within a range radius of 70% to 100% of the object ing.
The distance between the upper surface of the lower surface and the mounting table of the shower head structure For example is in the range of 20Mm～30mm, the flow rate of the inert gas is in the range of 3Sccm～100sccm.

Further , the related art of the present invention defines the processing method performed by the processing apparatus, that is, the processing gas is injected into the processing space of the processing container that can be evacuated from the gas injection hole of the shower head structure. In the processing method in which a predetermined process is performed on a target object that has been heated to a predetermined temperature by a heating means, a light introduction rod of a radiation thermometer is inserted into the gas injection hole, and the radiation temperature is The processing method is characterized in that the heating means is controlled based on a value detected by a meter.
Further , the related technology of the present invention is a temperature measuring means provided on a mounting table for injecting a processing gas into a processing space of a processing container which can be evacuated from a gas injection hole of a shower head structure and mounting an object to be processed. In the processing method in which the heating unit is controlled based on the detected value to perform the predetermined process while maintaining the object to be processed at the predetermined temperature, the heating unit is controlled based on the detected value of the temperature measuring unit. A continuous processing step for performing a predetermined process on a predetermined number of the objects to be processed by controlling, and a target object for the temperature calibration at this time while performing a predetermined process on the object for temperature calibration The temperature calibration processing step of detecting and monitoring the temperature of the gas by a radiation thermometer having a light introducing rod provided so as to be inserted into the gas injection hole, the detected value detected by the monitor, and the processing target Body goals It is a processing method characterized by having a temperature calibration step to calibrate the set temperature of the mounting table on the basis of the degrees value.

In this case, carried out with the continuous process if example embodiment, and the temperature calibration step, and the temperature calibration step, a cleaning step of cleaning the processing chamber when the repeated predetermined number of times.
Further, after performing the cleaning step if example embodiment performs precoating step wherein by supplying the processing gas in a state of not put the object to be processed into the processing chamber to form a thin film.
In this case, the light introducing rod Invite example embodiment, when the light introducing rod is made vertically movable, the at least during the cleaning process, the light introducing rod is retracted.

According to the shower head structure and the film forming apparatus of the present invention, the following excellent effects can be exhibited.
According to the first to third and sixth to eighth aspects of the present invention, since the light introduction rod of the radiation thermometer is inserted into the gas injection hole of the shower head structure, it is injected, for example, during the film forming process. The light introduction rod is covered with the processing gas, and it is possible to prevent the thin film from adhering to the light introduction surface. Therefore, the temperature of the object to be processed can always be accurately measured and detected.
In addition, since no special gas such as an inert gas is used to prevent thin film adhesion, the partial pressure of the source gas is not partially disturbed, and the in-plane uniformity of processing such as film formation is improved. Can be made.
The gas injection amount of the gas injection holes optical input rod is inserted through, since substantially the same as the gas injection quantity to be injected from the gas injection holes of other similar, may give rise to turbulence in the gas flow rate In addition, the in-plane uniformity of the processing such as the film thickness can be further improved than this point.
According to the inventions according to claims 4 and 5, for example, when the light introduction rod is not used, if the light introduction rod is retracted and separated from the processing space, the light introduction surface of the light introduction rod can be used, for example, during cleaning. It is possible to prevent surface roughness from being damaged.
According to the invention of請Motomeko 9,10, set temperature of the mounting table can be calibrated to always proper value, the processing temperature of the wafer at all times, a predetermined heat treatment while maintaining a substantially desired temperature value It can be carried out.
According to the eleventh aspect of the present invention, the heat rays directed to the portion other than the mounting table among the heat rays radiated from the heating lamp of the heating means are colored to hold the peripheral portion of the mounting table even when irregularly reflected inside. Since it is finally absorbed by the holding member or the shut-off ring, the diffusely reflected heat rays do not leak into the processing space and enter the radiation thermometer, so the temperature of the workpiece is measured with higher accuracy. can do.
According to the related art of the present invention, the main gas flow of the inert gas flowing so that the film does not adhere to the measurement window attached with the radiation thermometer is prevented from coming into contact with the surface of the object to be processed. , it is possible to prevent the film deposited on the surface of the object to be processed is locally thinner, it is the this mounting a radiation thermometer at the optimum position.

It is described in detail with reference to an embodiment of the shower head structure and thin film deposition apparatus according to the present invention in the accompanying drawings.
1 is a cross-sectional configuration diagram showing a processing apparatus having a shower head structure according to the present invention, FIG. 2 is a schematic diagram showing a gas ejection surface of the shower head structure, and FIG. 3 is an enlarged view showing a part of the gas ejection surface, FIG. 4 is an enlarged sectional view showing a part of the shower head structure. Here, a case where a tantalum oxide film, which is a metal oxide film, is formed by CVD as an example will be described.

First, as shown in FIG. 1, the processing apparatus 2 includes a processing container 4 formed into a cylindrical shape with, for example, aluminum. An exhaust port 8 is provided at the bottom 6 of the processing container 4 so that the inside of the processing container 4 can be evacuated. A shower head structure 12 is provided on the ceiling portion of the processing container 4 via a sealing member 10 such as an O-ring, and processing is performed from a number of gas injection holes 20A and 20B provided on the gas injection surface 18 on the lower surface. Various processing gases are jetted toward the space S.
In this processing container 4, a cylindrical reflector 22 erected from the bottom 6 of the processing container 4 is covered with, for example, three L-shaped holding members 24 (only two are shown in FIG. 1). A mounting table 26 for mounting a semiconductor wafer W as a processing body is provided.

Below the mounting table 26, a plurality of, for example, three L-shaped lifter pins 28 (only two in the illustrated example) are erected upward, and the base of the lifter pins 28 is A vertically long insertion hole (not shown) formed in the reflector 22 is inserted and connected to the ring member 30 in common. The ring member 30 is moved up and down by a push-up bar 32 provided through the bottom 6 of the processing container 4 so that the lifter pin 28 is inserted into a lifter pin hole 34 provided through the mounting table 26. The wafer W can be lifted.
A bellows 36 that can be expanded and contracted is provided in the penetrating portion of the container bottom 6 of the push-up bar 32 in order to maintain an airtight state inside the processing container 4, and the lower end of the push-up bar 32 is connected to an actuator 38. Yes.

Further, an exhaust passage 40 connected to a vacuum pump (not shown) is connected to the exhaust port 8 provided at the peripheral edge of the bottom of the processing container 4 so that the inside of the processing container 4 can be evacuated to a predetermined degree of vacuum. It has become. A gate valve 42 that is opened and closed when a wafer is carried in and out is provided on the side wall of the processing container 4.
In addition, a large-diameter bottom opening 44 is provided in the container bottom 6 immediately below the mounting table 26, and a transmission window 46 made of a heat ray transmitting material such as quartz is provided in the bottom opening 44 as a sealing member such as an O-ring. A box-shaped heating chamber 50 is provided below the transmission window 46 so as to surround the transmission window 46. In the heating chamber 50, for example, a plurality of heating lamps 52 are attached as a heating means to a rotating table 54 that also serves as a reflecting mirror, and the rotating table 54 is a rotation provided at the bottom of the heating chamber 50 via a rotating shaft. It is rotated by a motor 56. Accordingly, the heat rays emitted from the heating lamp 52 pass through the transmission window 46 and irradiate the lower surface of the thin mounting table 26 to heat it, and further indirectly heat the wafer W on the mounting table 26. To get.

  On the other hand, the shower head structure 12 provided on the ceiling portion of the processing container 4 is formed in the same manner as the structure previously disclosed in Japanese Patent Laid-Open No. 10-79377 by the present applicant. That is, the shower head structure 12 is provided so as to face the entire upper surface of the mounting table 26, and a processing space S is formed between the shower head structure 12 and the mounting table 26. The shower head structure 12 introduces a raw material gas for film formation, oxygen, or the like as a processing gas into the processing container 4 in a shower shape, and the gas injection surface 18 on the lower surface of the shower head structure 12 has a surface as described above. A large number of injection holes 20A and 20B for ejecting gas are formed.

The shower head structure 12 is divided into a source gas head space 60A and an assist gas head space 60B. The source gas head space 60A has an inert gas such as helium as a source gas. A metal oxide film raw material vaporized by a carrier gas, for example, metal alkoxide (Ta (OC ₂ H ₅ ) ₅ : pentethoxytantalum), is introduced so that the flow rate can be controlled. In addition, oxygen, which is an oxidizing gas here, is introduced into the assist gas head space 60B as an assist gas for performing a film forming reaction so that the flow rate can be controlled. The gas injection holes 20A and 20B are divided into two groups of a raw material gas injection hole 20A communicating with the raw material gas head space 60A and an assist gas injection hole 20B communicating with the assist gas head space 60B. At the time of film formation, the raw material gas ejected from the gas injection holes 20A and 20B and the assist gas oxygen are mixed in the processing space S and supplied in a so-called post-mixed state. In FIG. 2 and FIG. 3, in order to distinguish both gas injection holes, for convenience, the raw material gas injection holes 20A are indicated by hatched circles, and the assist gas injection holes 20B are indicated by white circles.

Further, in order to prevent the temperature of this portion from being liquefied and decomposed in the raw material gas, a heater 62 for heating to about 140 to 180 ° C. is provided on the side wall of the shower head structure 12. A heater 64 is also provided on the side wall of the container 4 to heat the wall surface, and the side surface is maintained at a temperature at which the raw material gas is not liquefied and is not thermally decomposed, for example, within a range of 140 to 180 ° C. It has become.
The shower head structure 12 is provided with a radiation thermometer 66 that is a feature of the present invention. Specifically, the radiation thermometer 66 is based on the light introduction rod 68 for actually collecting light from the semiconductor wafer W and the light (luminance) taken in by the light introduction rod 68. And a temperature detector 70 for determining the temperature of The light introducing rod 68 is formed as a thin rod-shaped body made of, for example, quartz or sapphire, and is provided in a straight line downward so as to penetrate the ceiling portion of the shower head structure 12. A sealing member 72 such as an O-ring for maintaining airtightness is interposed in the penetrating portion of the light introducing rod 68 with respect to the ceiling, and the lower portion of the light introducing rod 68 is shown in FIGS. As shown also, the gas is inserted into an assist gas injection hole 20B ′ positioned substantially at the center of the assist gas injection holes 20B formed on the gas injection surface 18 in large numbers. And this rod front-end | tip is set so that it may become substantially the same horizontal level as the opening end of the assist gas injection hole 20B. Accordingly, since O ₂ gas is injected from the assist gas injection hole 20B ′ at the time of film formation, it is possible to prevent an extra thin film from adhering to the light introduction surface 68A which is the tip of the light introduction rod 68. It has become. Here, the range in which light is collected is a range of a spread angle of about 45 ° at the tip of the light introduction rod 68. Accordingly, since there is a range of the spread angle, the installation positions of the temperature detection unit 70 and the light introduction rod 68 can be given a degree of freedom.

  Here, the raw material gas injection hole 20A and the assist gas injection hole 20B (including 20B ′) are suitable for the gas injection surface 18 so that a thin film is deposited on the surface of the wafer W so that the film thickness is uniform in the surface. Are arranged in a distributed manner. The important point of the present invention is that the light introduction rod 68 is inserted into one of the assist gas injection holes 20B '. As a result, it is not necessary to use an inert gas unnecessary for the film forming process in order to prevent the film from adhering to the light introducing rod 68. In this case, when the light introduction rod 68 is provided, if the gas flow rate disturbance or the gas partial pressure disturbance just below the assist gas injection hole 20B ′ inserted therethrough occurs, the assist gas injection hole 20B ′. Affects the film thickness of the wafer surface in the immediate vicinity of it, and causes in-plane uniformity of the film thickness to deteriorate. Therefore, the opening area S of the assist gas injection hole 20B ′ through which the light introduction rod 68 is inserted is It is preferable that the opening area S1 of the other assist gas injection hole 20B is set to be larger by an area S2 corresponding to the cross-sectional area of the light introducing rod 68. In other words, the gas injection area of the assist gas injection hole 20B ′ through which the light introduction rod 68 is inserted is a value obtained by subtracting the cross-sectional area S2 of the light introduction rod 68 from the opening area S, and this value is the other general It is preferable that the opening area S1 of the assist gas injection hole 20B, that is, the gas injection area is set to be approximately the same. Thus, even if the light introduction rod 68 is provided in the assist gas injection hole 20B ′, the assist gas It is possible to suppress as much as possible that the injection amount distribution is not adversely affected.

Specifically, although depending on the gas type and the like, the diameter D1 of the raw material gas injection hole 20A is, for example, about 2.5 mm, the diameter D2 of the general assist gas injection hole 20B is, for example, about 1 mm, Since the diameter D3 of the light introduction rod 68 is about 1.2 mm, for example, the diameter D of the assist gas injection hole 20B ′ inserted through the light introduction rod 68 is about 1.56 mm. That is, when the assist gas injection hole 20B is formed by drilling, the diameter of only the assist gas injection hole 20B ′ through which the light introduction rod 68 is inserted is made to be slightly larger.
Returning to FIG. 1, the output of the temperature detection unit 70 is input to a temperature control unit 74 made of, for example, a microcomputer. The temperature control unit 74 is based on the detection value of the temperature detection unit 70. The output of the heating lamp 52, which is a heating means, is controlled to control the wafer temperature.

Next, the processing method of the present invention performed using the processing apparatus configured as described above will be described.
First, an unprocessed semiconductor wafer W is loaded into the processing container 4 maintained in a vacuum state through a gate valve 42 opened from a transfer chamber or load lock chamber (not shown), and the lifter pins 28 are moved up and down. Thus, the wafer W is mounted on the mounting table 26.
Then, the processing chamber 4 is evacuated to maintain the predetermined process pressure, and the heating lamp 52 is driven to raise and maintain the semiconductor wafer W to a predetermined temperature. _Two gases are supplied to the processing space S, whereby a metal oxide film is formed.

In this case, Ta (OC ₂ H ₅ ) ₅ that is a liquid raw material is vaporized by a vaporizer using He gas and supplied as a raw material gas, and this supply system is used to prevent re-liquefaction of the raw material gas. As is well known, it is preheated to a predetermined temperature, for example, about 160 ° C.
The source gas flowing into the source gas head space 60 </ b> A of the shower head structure 12 is supplied to the processing space S from the source gas injection hole 20 </ b> A provided on the gas injection surface 18.

On the other hand, the O ₂ gas that has reached the assist gas head space 60B of the shower head structure 12 is supplied to the processing space S from the assist gas injection holes 20B and 20B ′ provided on the gas injection surface 18.
The source gas and O ₂ gas ejected into the processing space S are mixed and reacted in the processing space S, and a tantalum oxide film (Ta ₂ O ₅ ), for example, is deposited on the wafer surface to form a film. It will be.
At this time, the wafer temperature is in the range of 400 to 500 ° C., for example, about 480 ° C., and the surface temperature of the shower head structure 12 is, for example, about 150 ° C.
Here, the light from the surface of the wafer W is collected by the light introducing rod 68 of the radiation thermometer 66 provided in the assist gas injection hole 20B ′ at the substantially central portion of the gas injection surface 18, and the temperature is detected by the temperature detection. Determined by the unit 70. The wafer temperature detected by the radiation thermometer 66 is input to the temperature control unit 74. Based on the input wafer temperature, the temperature control unit 74 controls the output of the heating lamp 52 so that the wafer temperature is predetermined. Control to maintain the value of.

Under such circumstances, when an unnecessary thin film adheres to the light introduction surface 68A at the tip of the light introduction rod 68, a part of the light introduced into the light introduction rod 68 is absorbed by this thin film, and the wafer temperature is detected. Although the value may become inaccurate, in the case of the present embodiment, the O ₂ gas is also injected as the assist gas from the assist gas injection hole 20B ′ inserted through the light introduction rod 68. It is possible to prevent an unnecessary thin film from adhering to the surface 68A. Accordingly, since an unnecessary thin film hardly adheres to the light introduction surface 68A, the wafer temperature can always be detected almost accurately, so that the wafer temperature can be accurately controlled.
The light introducing rod 68 is not a specially provided mounting hole, and does not use an extra inert gas, but is provided in an assist gas injection hole 20B ′ for supplying an assist gas necessary for this film forming reaction. Since the assist gas prevents the excessive thin film from adhering, it does not adversely affect the partial pressure of the raw material gas in the vicinity of the portion where the light introduction rod 68 is provided, and the in-plane processing can be performed. This can be kept high without degrading the uniformity, i.e. the in-plane uniformity of the film thickness here.

Moreover, the gas injection area of the assist gas injection hole 20B ′ through which the light introduction rod 68 is inserted (= opening area S−the cross-sectional area S2 of the light introduction rod 68) is defined as the opening area S1 (= The gas injection area) is set to be substantially the same, so that the distribution of the injection amount of the O ₂ gas that is the assist gas is not adversely affected. From this point, the in-plane uniformity of the film thickness is further increased. It can be kept high.
Here, it is conceivable that the light introduction rod 68 is provided not in the assist gas injection hole 20B ′ but in the raw material gas injection hole 20A. In this case, the component in the raw material gas is the light introduction rod 68. Since the thin film is formed on the surface including the light introduction surface 68A, it is not preferable.

In addition, an evaluation experiment was conducted on whether or not the radiation thermometer 66 attached to the shower head structure 12 can measure and detect the temperature of the wafer W appropriately and accurately. explain.
FIG. 5 is a graph showing the difference between the measured temperature of the thermocouple (mounted on the wafer) before the film forming process and the measured temperature of the radiation thermometer, and FIG. 6 is the thermocouple before and after the film forming process (wafer mounted). It is a graph which shows the change of the difference of the measurement temperature of this, and the measurement temperature of a radiation thermometer.
First, in the case shown in FIG. 5, the process temperature is performed for three types of 440 ° C., 460 ° C., and 480 ° C., and the process pressure is 0.3 Torr (40 Pa) and 1.2 Torr (160 Pa) at each process temperature. And 2.5 Torr (333 Pa). N ₂ gas was supplied as an assist gas at 1000 sccm. The true temperature of the wafer is measured by directly attaching a thermocouple to the wafer.
As shown in the figure, the temperature difference, which is the difference between the measured value of the radiation thermometer and the measured value of the thermocouple, is in the range of −0.4 to + 0.4 ° C. at each temperature of 440 to 480 ° C., and ± 0 It was found that the wafer temperature could be accurately measured with a radiation thermometer because it showed a good result within the range of 5 ° C.

Next, in order to investigate the influence of the film formation process on the radiation thermometer, it is evaluated how the temperature difference before the film formation process actually changes and the temperature difference after the film formation process changes. Went. Here, Ta ₂ O ₅ (tantalum oxide film) having a thickness of 2 μm as a whole was formed. The process temperature is changed in three ways: 440 ° C., 460 ° C., and 480 ° C., and at each temperature, the process pressure is 0.3 Torr (40 Pa), 1.0 Torr (133 Pa), 2.5 Torr (333 Pa) and It was changed in four ways of 5.0 Torr (665 Pa).
As is clear from FIG. 6, in common with each process temperature, when the temperature is 0.3 Torr, the temperature difference reaches about −1.0 ° C., which is slightly inferior, but is within the range that can be used, and the process When the pressure was in the range of 1.0 to 5.0 Torr, all the temperature differences were within the range of ± 0.5 ° C., and it was found that particularly good results were shown.

Further, in the above embodiment, the case where one light introduction rod 68 is provided at the substantially central portion of the gas injection surface 18 of the shower head structure 12 has been described. There is a case where the temperature is controlled independently for each heating zone by dividing into zones, and in the case of such a device example, a light introduction rod 68 of a radiation thermometer may be provided for each heating zone. . FIG. 7 is a view showing the arrangement state of the light introduction rod with respect to the gas injection surface when the mounting table is divided into two heating zones of the inner periphery and the outer periphery, and FIG. 8 shows the mounting table of the inner periphery, the middle periphery, and the outer periphery. It is a figure which shows the arrangement | positioning state of the light introduction rod with respect to the gas injection surface when it divides | segments into three heating zones.
In the case shown in FIG. 7, the gas injection surface 18 of the shower head structure when the heating zone of the mounting table is concentrically separated into the inner peripheral zone and the outer peripheral zone is shown, and the inner periphery of the gas injection surface 18 is shown. The light introduction rod 68 is provided in correspondence with the outer circumference and the outer periphery, and the temperature of the mounting table can be controlled for each zone based on the detection value of each radiation thermometer.

8 shows the gas ejection surface 18 of the shower head structure when the heating zone of the mounting table is concentrically separated into the inner circumferential zone, the middle circumferential zone, and the outer circumferential zone. Light introducing rods 68 are provided corresponding to the inner circumference, the middle circumference, and the outer circumference of the gas injection surface 18, respectively, and the temperature of the mounting table is controlled for each zone based on the detection value of each radiation thermometer. be able to.
Here, the division | segmentation form of a heating zone is not limited to the above concentric division | segmentation form, What kind of division | segmentation form may be taken.

  In the above embodiment, this temperature is constantly measured by the radiation thermometer 66 during the heat treatment of the wafer W, and this measured value is input to the temperature controller 74 to feedback control the heating lamp 52 to control the wafer temperature. However, the present invention is not limited to this, and a thermocouple is provided on the mounting table 26, and the heating lamp is feedback-controlled by the measured value of the thermocouple, and the wafer temperature is measured periodically or irregularly using a radiation thermometer. And the set temperature value may be calibrated (corrected). The light introducing rod 68 can be bent around the shower head structure 12 by using a material that can be bent like an optical fiber, whereby the installation position of the temperature detecting unit 70 can be freely determined.

<First Modification>
FIG. 9 is a block diagram showing such a processing apparatus according to the first modification of the present invention. In addition, the same code | symbol is attached | subjected about the component same as the part shown in FIG. 1, and description is abbreviate | omitted.
As shown in the drawing, here, for example, a thermocouple 80 is provided as a temperature measuring means on the mounting table 26, and the detected value measured here is input to the temperature control unit 82, and based on this detected value, to the heating lamp 52. The power is controlled so that the mounting table 26 maintains a predetermined set temperature value.
On the other hand, the detected value measured by the radiation thermometer 66 provided in the shower head structure 12 is input to the temperature calibration control unit 84, and this detected value and the thermocouple 80 are used as necessary. Based on the above, the set temperature value in the temperature control unit 82 can be calibrated.

Next, the operation of this apparatus example will be described.
First, the reason for calibrating the set temperature value as described above is as follows.
In general, the contact surface between the mounting table 26 and the wafer W is not microscopically uniform, and since there is a slight non-uniform gap, this becomes a thermal resistance and the true temperature of the wafer W is It is inevitable that a temperature difference will occur at a temperature several degrees lower than the true temperature of 26, for example, about 5 ° C. Therefore, when the temperature of the mounting table 26 is controlled during the heat treatment, the set temperature value of the mounting table is determined in consideration of the temperature difference. For example, when it is desired to perform the heat treatment at a wafer temperature of 460 ° C., the set temperature value of the mounting table 26 is set to 465 ° C. in consideration of the temperature difference, for example, 5 ° C.

If a certain number of wafers are formed as the film formation process proceeds, a thin film adheres to the inner wall of the processing container and the like, and this changes, for example, decreases the internal heat reflectivity. For this reason, although the temperature of the mounting table 26 is maintained at 465 ° C., the wafer W is not sufficiently heated to the target temperature of 460 ° C., for example, maintained at 457 ° C., which is 3 ° C. lower. It will end up. In such a case, the set temperature value of the mounting table 26 is calibrated by the amount of 3 ° C. when the temperature is lowered, and here, it is reset to 468 ° C. (= 465 ° C. + 3 ° C.). It becomes possible to maintain the temperature at 460 ° C. again.
At the time of actual heat treatment, first, a predetermined number of wafers W, for example, only 25 wafers in one lot are continuously heat-treated (film formation) (this is referred to as a continuous treatment process). During this continuous processing step, the detected value from the radiation thermometer 66 is not used, and the temperature controller 82 always uses the detected value measured by the thermocouple 80 provided on the mounting table 26 for feedback control of the heating lamp 52. To do. Here, the set temperature value of the mounting table 26 assumes that the temperature difference between the initial mounting table 26 and the wafer W is 5 ° C. in order to set the temperature of the wafer W to 460 ° C. as described above. 465 ° C.

  When a predetermined number of wafers have been processed in this way, the process proceeds to the next temperature calibration process. Here, not a product wafer W but a temperature calibration dummy wafer, which is an object to be temperature-calibrated, is carried into the processing container 4 so that the process pressure and the process temperature are the same as those of the product wafer described above. Process. At this time, the process gas for film formation may not be supplied. When heat-treating the temperature calibration dummy wafer, the radiation thermometer 66 provided in the shower head structure 12 is also operated to detect and monitor the temperature of the dummy wafer, and the detected value is the temperature calibration control unit. 84. At the same time, the detected value measured by the thermocouple 80 is also input to the temperature calibration control unit 84.

  When the temperature calibration processing step is thus completed, the process proceeds to the temperature calibration step. That is, the set temperature value for the mounting table 26 of the temperature control unit 82 is calibrated based on the detected value of the monitored radiation thermometer 66 and the target temperature value of the wafer W. The target temperature value may be stored in advance, or may be obtained as information from the temperature control unit 82 side. For example, as described above, when the wafer temperature is 457 ° C. (detection value of the radiation thermometer) which is 3 ° C. lower than the target temperature value of 460 ° C., the mounting table 26 is instructed to the temperature control unit 82. Is calibrated to 468 ° C. as a new set temperature value. In this way, the set temperature value is set to 468 ° C., and from the next wafer processing, the temperature of the mounting table 26 is controlled to be 468 ° C. which is the reset set temperature value. The target temperature value is maintained at 460 ° C.

The continuous processing step, the temperature calibration processing step, and the temperature calibration step are repeated a predetermined number of times in this order.
In this way, the set temperature value of the mounting table can always be calibrated to an appropriate value, and the predetermined heat treatment can be performed while the processing temperature of the wafer W is constantly maintained at a substantially target temperature value.
Further, as described above, if each of the above steps is repeated a predetermined number of times, a large amount of unnecessary films that cause particles adhere to the processing container 4. For example, ClF ₃ , NF ₃ , A cleaning process is performed by flowing a cleaning gas such as C ₂ F ₆ or CF ₄ into the processing container 4 to remove the unnecessary film.
If such a cleaning process is performed, the wafer W is not put into the processing container 4 under the same process conditions as the film forming process in order to adjust the thermal condition in the processing container 4. A pre-coating process is performed in which a thin film is attached to the inner wall of the processing container 4 and the surface of the structure in the processing container 4 by flowing a processing gas or the like.

If such a pre-coating process is performed, the reflectance of the wall surface and the like in the processing container 4 also changes, so that the above-described temperature calibration process and temperature calibration process are performed before the product wafer is flowed. It is good to do. Thereby, even after cleaning, the set temperature value of the mounting table can be calibrated to an appropriate value.
The number of wafers W to be processed in the continuous processing step is not limited to 25, and can be arbitrarily set based on the film formation amount per wafer.

<Second Modification>
In each of the above embodiments, the case where the light introduction rod 68 of the radiation thermometer 66 is fixedly described has been described as an example. However, the present invention is not limited to this, and the light introduction rod 68 can be moved up and down. It is good also as a structure which can retract | save the light introduction rod 68 from the processing space S when needed.
10 is a block diagram showing a second modification of the processing apparatus when the processing apparatus shown in FIG. 1 is provided with the light introduction rod so that it can be moved up and down, and FIG. 11 shows the operation of the light introduction rod of the processing apparatus shown in FIG. FIG.

As shown in FIGS. 10 and 11, in the case of this embodiment, a rod through hole 90 is provided through the head ceiling plate 12A of the shower head structure 12 so that it can be moved up and down freely. The light introduction rod 68 is inserted in the state. A bellows 92 made of, for example, a metal bellows is interposed between the upper end of the light introducing rod 68 and the head ceiling portion 12A to maintain the airtightness in the assist gas head space 60B. However, the light introduction rod 68 can be allowed to move up and down.
The upper end of the light introduction rod 68 or the upper end of the bellows 92 is connected to an arm 94A of a rod elevating mechanism 94 made of an actuator, for example, and the light introduction rod 68 is raised and lowered as necessary. ing.

In this embodiment, for example, when performing the temperature calibration processing step, the light introducing rod 68 is lowered to the lowest end as shown in FIG. 11A, and the light introducing surface 68A is exposed to the processing space S. Keep it. During normal processing (for example, during film formation) or continuous processing (for example, during continuous film formation processing), and further during the cleaning process, the light introduction rod 68 is raised as shown in FIG. It is held at a position where the film does not adhere to the light introduction surface 68A at the tip, or at a position where it is not scraped by the cleaning gas (in the example shown, it is raised to the assist gas head space 60B).
Accordingly, an unnecessary film is not attached to the light introduction surface 68A, or this portion is not scraped by the cleaning gas and the surface is not roughened. Therefore, the incident light of the light incident from this light introduction surface 68A The rate does not fluctuate and the reproducibility of the temperature calibration can be kept high.
When the light introducing rod 68 is used during film formation, the light introducing rod 68 is naturally lowered as shown in FIG.

  In the above embodiment, there is a risk that a certain amount of assist gas may enter the bellows 92 from the assist gas head space 60B. However, as shown in FIG. A small isolation valve 96 such as a gate valve that can be opened and closed to close the door may be provided. The isolation valve 96 can also insert the light introducing rod 68. When the isolation valve 96 is completely pulled upward as shown in FIG. 12B, the isolation valve 96 is closed to completely close the inside of the bellows 92. Be able to.

In this case, when the light introduction rod 68 is not used, the light introduction rod 68 is raised and completely accommodated in the bellows 92 and the isolation valve 96 is closed as shown in FIG. Not only can an unnecessary film adhere to the introduction surface 68A or the surface roughness due to the cleaning gas can be reliably prevented, but also the assist gas can be prevented from flowing into the elongated bellows 92.
In each of the above-described embodiments, the case where the heating lamp 52 is employed as the heating means has been described. However, the present invention is not limited to this, and the present invention can be applied to the case where a resistance heater embedded in the mounting table is used as the heating means. Can be applied.
Further, the present invention is not limited to the film forming process, and the present invention can be applied to an etching processing apparatus that performs a process that may cause a thin film to adhere to the light introducing rod, for example, a plasma etching process. In this case, in the shower head structure, the light introduction rod may be provided in the injection hole for injecting the etching gas.

<Third Modification>
In each of the above embodiments, the mounting table 26 is supported by three rod-shaped holding members 24 made of, for example, quartz L-shape, so that the heat rays radiated from the heating lamp 52 are applied to the mounting table 26. After diffusely reflecting below 26, the light passes through a gap between the upper end of the reflector 22 and the outer periphery of the mounting table 26 and enters the processing space S side. Further, this heat ray is diffusely reflected in the processing space S to introduce light. Since the rod 68 may enter, the wafer temperature measured by the radiation thermometer 66 becomes a detection value considerably higher than the actual wafer temperature, and the detection accuracy may be lowered.
In addition to the holding member 24, there is also known a conventional apparatus in which the mounting table 26 is made of ring-shaped transparent quartz. In this case, the irregularly reflected heat rays pass through the transparent quartz. Similarly, since it enters the processing space S side, there is a problem similar to that described above. This third modification is intended to suppress the above-described adverse effects due to the irregular reflection of heat rays.

FIG. 13 is a block diagram showing a third modification of the processing apparatus of the present invention. Here, the same components as those shown in FIG. 9 are denoted by the same reference numerals, and the description thereof is omitted.
Here, the support structure of the mounting table 26 is greatly changed from each of the embodiments described above. That is, a cylindrical reflector 22 whose inner surface is, for example, a mirror surface is provided upright below the mounting table 26, and heat rays radiated from the lower heating lamp 52 are placed on the upper mounting table 26 side. Can be reflected. On the outer peripheral side of the reflector 22, for example, an aluminum support cylinder 100 that is also formed in a cylindrical shape is provided concentrically with the reflector 22.

For example, a circular ring-shaped attachment member 102 made of aluminum is attached and fixed to the upper end portion of the support cylinder 100. Further, on the inner peripheral side of the circular ring-shaped attachment member 102, a holding member 104, which is a feature of the present invention and has a smaller radius than that of the circular ring-shaped attachment member 102, is also provided. The holding member 104 is formed of a material having low thermal conductivity and colored so as to effectively block the heat rays radiated from the heating lamp 52. Then, at the inner peripheral edge of the holding member 104, the mounting table 26 is supported by being brought into direct contact with the peripheral edge of the mounting table 26 made of, for example, SiC.
As the material of the holding member 104, a material having low thermal conductivity is preferable in order not to lower the temperature of the mounting table 26 as described above, and a material that does not transmit heat rays is preferable. Specifically, the material of the holding member 104 includes quartz containing a black metal oxide such as niobium oxide, quartz containing black SiC, quartz containing carbon, black AlN containing carbon, and the like. Any of black ceramics or the like can be used.

  In the example of the apparatus configured as described above, among the heat rays radiated from the heating lamp 52, the heat rays irradiated to other than the back surface of the mounting table 26 are diffusely reflected in the space below the mounting table 26. However, the irregularly reflected light is finally absorbed by the back surface of the mounting table 26 or the holding member 104 colored in black, for example. Therefore, this irregularly reflected light can be prevented from leaking out to the processing space S side above the mounting table 26 and being taken into the light introducing rod 68 of the radiation thermometer 66. Therefore, the wafer temperature can be measured more accurately by the radiation thermometer 66.

<Fourth Modification>
Next, a fourth modification of the present invention will be described.
FIG. 14 is a block diagram showing a fourth modification of the processing apparatus of the present invention. In addition, the same code | symbol is attached | subjected about the same component as the part shown in FIG.1, FIG9 and FIG.13, and the description is abbreviate | omitted. Here, a case where a PZT film (Pb, Zr, Ti oxide film) is deposited as a composite metal material thin film instead of a tantalum oxide film will be described as an example.
In the fourth modified example, the support structure of the mounting table 26 is provided with a ring-shaped attachment member 102 on the support tube 100 as described in FIG. For example, a black circular ring-shaped holding member 104 that does not transmit heat rays is provided, and the mounting table 26 is supported by the inner peripheral edge of the holding member 104.

  As the radiation thermometer attached to the shower head structure 12, a radiation thermometer 110 of a type not provided with the light introducing rod 68 (see FIGS. 9 and 13) is used here. That is, a heat ray outlet passage 112 having a diameter of, for example, about 13 mm is formed in the vicinity of the substantially central portion of the shower head structure 12 so as to penetrate the shower head structure 12 in the vertical direction. As a matter of course, the heat ray outlet passage 112 is separated from the source gas head space 60A and the assist gas head space 60B. A measurement window 116 made of, for example, quartz glass is airtightly attached and fixed to the upper end opening of the heat ray outlet passage 112 via a seal member 114 such as an O-ring. The radiation thermometer 110 is attached to the outside of the measurement window 116, and the temperature measurement can be returned by sensing the heat rays radiated from the surface of the wafer W through the heat ray derivation passage 112. ing. The heat ray is detected within a range of a spread angle of about 45 ° from the tip of the heat ray outlet passage 112.

Further, the heat ray outlet passage 112 in the vicinity immediately below the measurement window 116 is branched from this to form an inert gas introduction passage 118, and a small amount of inert gas such as, for example, an inert gas introduction passage 118 is formed. By constantly flowing Ar gas, it is possible to prevent an unnecessary film that obstructs temperature measurement from adhering to the inner surface of the measurement window 116. Here, since the PZT gas is introduced into the upper space in the shower head structure 12 and the oxidizing gas NO ₂ gas is introduced into the lower space, the upper space is the source gas, contrary to the above-described embodiment. The head space 60A is used, and the lower space is the assist gas space 60B. Accordingly, the signing of the gas injection holes 20A and 20B in FIG. 14 is changed.
In the apparatus example configured as described above, PZT gas generated by vaporizing the raw material liquid in the vaporizer is introduced into the raw material gas head space 60A of the shower head structure 12. At this time, for example, Ar gas is used as an inert gas for the carrier gas in the vaporizer. Further, for example, NO ₂ gas is supplied as an oxidizing gas to the assist gas space 60B. Then, both the gases are mixed in the processing space S, and a PZT film is deposited on the wafer W.

The temperature of the wafer W at this time is measured when the radiation thermometer 110 detects a heat ray traveling through the heat ray derivation passage 112 provided in the shower head structure 12. In this case, since a small amount of Ar gas is constantly supplied and purged through the inert gas introduction passage 118 in the heat ray outlet passage 112, an unnecessary film adheres to the inner surface of the measurement window 116. Can be prevented. At this time, the flow rate of the purge Ar gas is, for example, about 2 to 3 sccm, which is far less than this when the carrier gas of PZT gas is about 300 sccm, for example.
Here, as described with reference to FIG. 13, among the heat rays emitted from the heating lamp 52, the heat rays irradiated to the part other than the back surface of the mounting table 26 are diffusely reflected in the space below the mounting table 26. However, the irregularly reflected light is finally absorbed by the back surface of the mounting table 26 or the holding member 104 colored in black, for example. Therefore, this irregularly reflected light can be prevented from leaking out to the processing space S side above the mounting table 26 and being taken into the radiation thermometer 110. Therefore, the wafer temperature can be measured more accurately by the radiation thermometer 110.
As the inert gas for the purge gas and the carrier gas, other inert gas such as He gas, Ne gas, N ₂ gas or the like can be used instead of Ar gas.
Further, the present invention can also be applied when forming another composite metal material film such as a BST film (Ba, Sr, Ti oxide film) instead of the PZT film.

Here, since the evaluation of the measured value of the radiation thermometer 110 by the apparatus of the present invention described above was actually performed, the evaluation result will be described.
In this evaluation, a thermocouple was actually attached to the wafer surface and its temperature was measured. When the holding member 104 for holding the mounting table 26 is formed of transparent quartz glass as in the conventional structure, the measured value of the wafer temperature by the thermocouple is about 433 ° C., whereas the measured value by the radiation thermometer 110 is used. The measured value was about 40 ° C. higher than that and was not stable.

  On the other hand, in the case of the present invention in which the holding member 104 is black quartz glass, as a result of measuring eight times as shown in FIG. 15, the wafer temperature by the thermocouple is about 433 ° C., The measured value by the radiation thermometer 110 is only about + 2 ° C. higher than that, and it has been found that the measurement accuracy of the wafer temperature can be greatly improved.

<Fifth Modification>
Next, a fifth modification of the present invention will be described.
FIG. 16 is a schematic view showing a fifth modification of the processing apparatus of the present invention, and FIG. 17 is a partially enlarged sectional view showing the periphery of the mounting table of the processing apparatus shown in FIG. Note that the same components as those shown in FIG. 14 are denoted by the same reference numerals and description thereof is omitted.
In the fifth modification, the attachment member 102 is stretched between the upper portion of the cylindrical reflector 22 and the upper portion of the support tube 100, and the holding member 104 is formed by a protrusion 22 </ b> A formed on the upper portion of the reflector 22. The mounting table 26 is held via the above. And on the upper surface of this holding member 104, the interruption | blocking ring 120 which interrupts | blocks the heat ray which is the characteristics of this invention is provided. Specifically, as shown in FIG. 17, an annular protrusion 122 is formed on the upper surface of the peripheral portion of the mounting table 26 so as to surround the periphery of the wafer W in order to suppress heat dissipation from the peripheral portion of the wafer W. Is formed. Further, a flange portion 124 for holding by the holding member 104 is formed at the peripheral portion of the mounting table 26. The holding member 104 includes a lower holding member 104A and an upper holding member 104B joined to the lower holding member 104A. The flange portion 124 is held between the upper and lower holding members 104A and 104B from above and below. It has become.

The lower holding member (also referred to as a base ring) 104A has a function as a base for positioning the mounting table 26 in the height direction. The upper holding member (also referred to as an isolation ring) 104B has a function of positioning the mounting table 26 in the horizontal direction and the mounting table 26 is skipped during initial roughing when the processing container 4 is depressurized. And has a function of pressing from above to prevent movement.
These upper and lower holding members 104B and 104A are preferably formed of a material having heat resistance, non-contamination with respect to the wafer W, and low thermal conductivity, such as alumina (Al ₂ O ₃ ). The material of the upper and lower holding members 104B and 104A may be, for example, silicon carbide, silicon oxide (SiO ₂ ), quartz or the like other than alumina.

  The upper and lower holding members 104B and 104A are made of a material that does not transmit heat rays, for example, quartz containing a black metal oxide such as niobium oxide, quartz containing black SiC, as in the case of the fourth modification. Alternatively, it may be formed of any one of black ceramics such as quartz containing carbon and black AlN containing carbon.

  The blocking ring 120 is installed so as to cover the entire upper surface of the upper holding member 104B and the upper surface of the protrusion 122 of the mounting table 26 over substantially the entire area. The heat rays passing through the mounting table 26 from the lower side to the upper side are blocked as much as possible. In this case, the thickness of the shut-off ring 120 is, for example, about 1.5 mm, and a protrusion that fits into a step formed on the upper surface of the upper holding member 104B and performs positioning on a part of the lower surface thereof. 126 is formed in a ring shape. Further, providing the inner peripheral end of the blocking ring 120 as close as possible to the outer peripheral end of the wafer W is excellent in terms of blocking heat rays, but at least the blocking ring 120 is provided on the upper surface of the upper holding member 104B. Provide to cover the entire surface. The material of the blocking ring 120 is, for example, quartz containing black metal oxide such as niobium oxide, quartz containing black SiC, quartz containing carbon, black AlN containing carbon, etc. It consists of one of ceramics. Specifically, when AlN is used as the material of the blocking ring 120, carbon of about 1060 ppm or more may be contained.

Also in this case, it is possible to prevent irregularly reflected light (including heat rays) generated below the mounting table 26 from leaking out to the processing space S side above the mounting table 26 and being taken into the radiation thermometer 110. Therefore, the wafer temperature can be measured more accurately by the radiation thermometer 110. In particular, when at least one of the lower holding member 104A and the upper holding member 104B is formed of a material that does not transmit heat rays as described above, the above-described heat ray blocking effect can be further improved.
In the third modification, the fourth modification, and the fifth modification, the holding member 104 or the blocking ring 120 made of a material that blocks heat rays naturally blocks visible light.

<6th and 7th modification>
Next, sixth and seventh modifications of the present invention will be described.
18 is a schematic configuration diagram showing a sixth modification of the processing apparatus of the present invention, FIG. 19 is a diagram schematically showing the surface of a semiconductor wafer when a film is formed using the sixth modification, and FIG. FIG. 21 is a schematic configuration diagram showing a seventh modification, and FIG. 21 is a diagram schematically showing the surface of a semiconductor wafer when a film is formed using the seventh modification.
18 and 20 are both based on the configuration shown in FIG. 16, but the detailed description thereof is omitted, and the same components are denoted by the same reference numerals and the description thereof is omitted.

  In each of the apparatus examples shown in FIGS. 13, 14 and 16, a heat ray outlet passage 112 formed so as to penetrate the shower head structure 12 in the vertical direction and a radiation thermometer 110 are provided. The temperature at the substantially central portion of the wafer W is measured. However, depending on the heating method of the wafer W, the central portion of the wafer W generally becomes a thermal singular point, and a temperature difference occurs between the central portion of the wafer W and other portions of the wafer W. In some cases, it is not preferable to measure the temperature of the central portion of the wafer W and use it as a temperature reference for the wafer W.

Therefore, in the sixth modification, the heat ray deriving passage 112 and the center of the shower head structure 12 are decentered from the center line C1 indicating the center of the shower head structure 12 (which also coincides with the center line of the wafer W) by a predetermined distance L1. A radiation thermometer 110 is provided so that temperature detection of a singular point of the wafer W can be avoided.
By the way, an inert gas, such as Ar gas, introduced from the inert gas introduction passage 118 for the purpose of preventing the film from adhering to the inner surface of the measurement window 116, is obtained from the lower end opening 112A of the heat ray extraction passage 112. The Ar gas flows out or is released downward, and the Ar gas is uniformly evacuated in the outer peripheral portion of the mounting table 26, and thus diffuses while flowing down toward the outside of the mounting table 26. Thus, when the eccentric distance L1 is simply set to about several centimeters, the Ar gas main gas flow 130 directly hits a partial area 132 on the surface of the wafer W as shown in FIG. There is a phenomenon that the thickness of the deposited film in the circular area 132 having a diameter of about several centimeters on the surface of the wafer becomes thinner than other portions. In FIG. 19, the projection position of the lower end opening 112A of the heat ray derivation passage 112 is also shown for reference.

  In this case, depending on the flow rate of Ar gas and the size of the gap between the lower surface of the shower head structure 12 and the upper surface of the mounting table 26, the eccentric distance L1 is about 4.2 cm for an 8-inch wafer. The distance M1 from the center of the wafer to the center of the area 132 is about 6.0 cm. At this time, the diameter of the heat ray outlet passage 112 is about 1.3 cm, and the diameter of the area 132 is about 3.0 cm. Therefore, in order to eliminate the occurrence of thinning in the area 132, in the seventh modified example, as shown in FIGS. 20 and 21, the center line C1 of the shower head structure 12 and the lower end opening of the heat ray outlet passage 112 are used. The eccentric distance L2 between the center of 112A and the Ar gas (inert gas) that diffuses while flowing out from the lower end opening 112A of the heat ray outlet passage 112 and flowing down to the outside of the mounting table 26. The center of the position where the main gas flow 130 flows down to the same horizontal level as the upper surface of the mounting table 26 is set to be outside the outer peripheral edge of the semiconductor wafer W mounted on the mounting table 26. Yes. In other words, the eccentric distance L2 is set large so that the main gas flow 130 does not contact the surface of the wafer W on the mounting table 26 as directly as possible.

FIG. 21 shows a state in which the main gas flow 130 is in contact with the area 134 indicated by the broken line in the outer peripheral portion of the wafer W as described above. Here, as an example, since the area 134 does not have to cover the semiconductor device (element formation area) on the wafer W, the case where the approximate center of the area 134 is located at the outer peripheral edge of the wafer W is shown. At this time, the distance M2 from the center of the wafer W to the center of the area 134 is the radius of the wafer, that is, 10.0 cm here. Here, the maximum value of the eccentric distance L2 is the size of the wafer radius because the temperature cannot be measured unless the radiation thermometer 110 faces the wafer surface.
Thereby, it is possible to prevent the main gas flow 130 of the inert gas (Ar gas) from coming into direct contact with the surface of the wafer W, and to prevent a thin film portion from being locally generated on the wafer surface. . Incidentally, if the eccentric distance L2 is set to about 8.0 cm, a good result can be obtained without showing traces of the area 132 where the film thickness is locally thin. Since the radius of the wafer W is 10 cm (in the case of an 8-inch size), the eccentric distance L2 is preferably set within a range of 70% to 100% of the radius of the wafer W. When this point is represented by a relational expression, M1 / L1 = M2 / L2, and therefore 6.0 / 4.2 = 10 / L2, and L2 = 7.0 cm. That is, the length of L2 is preferably in the range of 7.0 to 10.0 cm.

  The process conditions at this time are such that the flow rate of the purge inert gas (Ar gas) is, for example, 9 sccm within a range of 3 sccm to 100 sccm, and the distance between the lower surface of the shower head structure 12 and the upper surface of the mounting table 26 is 20 mm to For example, 25 mm within the range of 30 mm, the pressure in the processing container 4 is about 133 Pa, and the total flow rate of the source gas is about 500 sccm. Further, this embodiment can be applied not only to an 8-inch wafer but also to a 12-inch wafer (diameter 300 mm). Further, in the case of the sixth and seventh modified examples, the heating means is not limited to the one using a heating lamp, but can be applied to a processing apparatus of a type in which a resistance heater is built in the mounting table 26. it can.

In each of the above-described embodiments, the case where a tantalum oxide film or a PZT film is formed as an example has been described. However, the present invention can be applied to the case where other film types are deposited. For example, as another film type, when a tungsten film is formed by thermal CVD using WF ₆ gas and H ₂ gas, a TiN film is formed by thermal CVD using TiCl ₄ gas and NH ₃ gas. In this case, the present invention can be applied to a case where a Ti film is formed by plasma CVD using TiCl ₄ gas and H ₂ gas. In this case, a light introducing rod of a radiation thermometer is provided in a gas injection hole of a reducing gas, that is, an assist gas, that is, H ₂ gas or NH ₃ gas.
Further, as the inert gas, for example, N ₂ gas, He gas or the like can be used in addition to Ar gas.
In the present invention, a semiconductor wafer has been described as an example of the object to be processed. However, the present invention is not limited to this and can be applied to an LCD substrate, a glass substrate, or the like.

It is a section lineblock diagram showing the processing device provided with the shower head structure concerning the present invention. It is a schematic diagram which shows the gas injection surface of a shower head structure. It is an enlarged view which shows a part of gas injection surface. It is an expanded sectional view showing a part of shower head structure. It is a graph which shows the difference of the measured temperature of the thermocouple (attached to a wafer) before performing a film-forming process, and the measured temperature of a radiation thermometer. It is a graph which shows the change of the difference of the measured temperature of the thermocouple (wafer mounting) before and behind performing film-forming processing, and the measured temperature of a radiation thermometer. It is a figure which shows the arrangement | positioning state of the light introduction rod with respect to the gas injection surface when a mounting base is divided | segmented into two heating zones of an inner periphery and an outer periphery. It is a figure which shows the arrangement | positioning state of the light introduction rod with respect to the gas injection surface when a mounting base is divided | segmented into three heating zones of an inner periphery, a middle periphery, and an outer periphery. It is a block diagram which shows the processing apparatus of the 1st modification of this invention. It is a block diagram which shows the 2nd modification of a processing apparatus when the light introduction rod is provided in the processing apparatus shown in FIG. 1 so that raising / lowering is possible. It is the elements on larger scale which show operation | movement of the light introduction rod of the processing apparatus shown in FIG. It is the elements on larger scale which show the other modification when the light introduction rod is provided so that raising / lowering is possible. FIG. 13 is a block diagram showing a third modification of the processing apparatus of the present invention. It is a block diagram which shows the 4th modification of the processing apparatus of this invention. It is a table | surface which compares the detection value of the radiation thermometer by the 4th modification of the processing apparatus of this invention with the detection value of a thermocouple. It is a schematic diagram which shows the 5th modification of the processing apparatus of this invention. It is a partial expanded sectional view which shows the peripheral part of the mounting base of the processing apparatus shown in FIG. It is a schematic block diagram which shows the 6th modification of the processing apparatus of this invention. It is a figure which shows typically the surface of a semiconductor wafer when forming into a film using a 6th modification. It is a schematic block diagram which shows the 7th modification. It is a figure which shows typically the surface of the semiconductor wafer when it forms into a film using a 7th modification.

Explanation of symbols

DESCRIPTION OF SYMBOLS 2 Processing apparatus 4 Processing container 12 Shower head part 18 Gas injection surface 20A Raw material gas injection hole 20B Assist gas injection hole 26 Mounting stand 46 Transmission window 52 Heating lamp (heating means)
60A Raw material gas head space 60B Assist gas head space 66 Radiation thermometer 68 Light introduction rod 68A Light introduction surface 70 Temperature detection unit 74 Temperature control unit 80 Thermocouple (temperature measurement means)
82 Temperature control unit 84 Temperature calibration control unit 90 Rod through hole 94 Rod lifting mechanism 96 Isolation valve 102 Attachment member 104 Holding member 110 Radiation thermometer 116 Measurement window 120 Shut-off ring 130 Main gas flow S Processing space W Semiconductor wafer (object to be processed) )

Claims (11)

In order to perform a film forming process on the object to be processed, a plurality of first gas injection holes for discharging the source gas and a plurality of holes for discharging the assist gas to the processing space containing the heated object to be processed of a second gas injection hole, the at least one of the second gas injection hole, the second gas injection hole is passed through the light introducing rod the light introducing rod with kick set provided in the radiation thermometer The opening area is set to be larger by the area corresponding to the cross-sectional area of the light introduction rod than the opening area of the other gas injection hole through which the same type of gas as the gas injected from the other second gas injection hole is injected. shower head structure, characterized in that I was sea urchin configuration is. The showerhead structure according to claim 1, wherein the light introducing rod is positioned at a central portion of the gas injection surface . The light introducing rod, shower head structure according to claim 1, wherein the provided plurality along the radial direction including the center of the gas injection reflecting surface. The light introducing rod, shower head structure according to any one of claims 1 to 3, whichever is one wherein, characterized in that it is provided connected to the rod lifting mechanism so that it can be retracted as needed to vertically movable. The light introducing rod is inserted through a rod through hole provided in a ceiling plate of the shower head structure, and the rod through hole is inserted into an upper end portion of the rod through hole when the light introducing rod is retracted. shower head structure of請Motomeko 4 Symbol mounting, characterized in that it is provided with isolation valves for closing. Shower head structure according to claim 1乃optimum 5 gall deviation or claim, characterized in that the assist gas is an oxidation gas. Shower head structure according to any one of claims 1乃optimum 5, characterized in that the assist gas is a reducing gas. In a film forming apparatus for performing a film forming process on an object to be processed,
A processing vessel that can be evacuated;
A mounting table for mounting the object to be processed;
Heating means for heating the object to be processed;
A shower head structure as claimed in any one of claims 1乃Itaru 7,
A temperature control unit for controlling the heating means based on a detection value of a radiation thermometer provided in the shower head structure;
The film-forming processing apparatus characterized by the above-mentioned. In a film forming apparatus for performing a film forming process on an object to be processed,
A processing vessel that can be evacuated;
A mounting table for mounting the object to be processed;
Temperature measuring means provided on the mounting table,
Heating means for heating the object to be processed;
A shower head structure according to claim 1乃Optimum 7 Neu deviation or claim,
A temperature control unit for controlling the heating unit based on a detection value of the temperature measuring unit during a film forming process of the object to be processed;
In the temperature control unit based on the detection value of the radiation thermometer provided in the shower head structure and the target temperature value of the object to be processed when the film forming process is performed using the object for temperature calibration. A temperature calibration control unit for calibrating the set temperature value of the mounting table, and
The film-forming processing apparatus characterized by the above-mentioned. It said temperature measuring means, the film forming apparatus according to claim 9 Symbol mounting, characterized in that a thermocouple. The heating means includes a heating lamp, and the mounting table is held by a ring-shaped holding member having a low thermal conductivity and colored so as to block heat rays from the heating lamp. Item 11. The film forming apparatus according to any one of Items 8 to 10 .

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