Wafer processing apparatus

Abstract

The wafer processing apparatus of the present invention is characterized by comprising: a processing chamber (104) which is disposed inside a vacuum container and inside which a gas for processing is received; a sample stage (201) which is disposed in the processing chamber, supports a wafer to be processed, and has a cylindrical shape; a step section that annularly surrounds a placement surface on which a wafer (204) is placed at the upper part of the sample stage; a gas dispersion plate (208) which is placed on the bottom surface of the stepped part and has a ring shape surrounding the placement surface; a susceptor ring (205) placed on the upper surface of the gas dispersion plate and surrounding the placement surface; and a flow path through which an inert gas flows, the flow path comprising a gap between the bottom surface of the gas dispersion plate and the bottom surface of the stepped part, a gap between the inner peripheral side wall of the gas dispersion plate and the outer peripheral side wall of the stepped part, and a gap between the inner peripheral side wall of the susceptor ring and the outer peripheral side wall of the stepped part. Recesses (401) extending in the vertical direction are provided in a plurality of locations on the inner peripheral side wall of the base ring.

Description

Technical Field

[0001] The present invention relates to a wafer processing device, wherein the wafer processing device supplies gas to the back side of the outer peripheral edge of the wafer along the inner peripheral surface of an annular member arranged along the outer periphery of the upper surface of the sample table, and performs wafer processing on a film layer of a processing object such as a substrate-shaped sample such as a semiconductor wafer carried on the upper surface of the sample table in a processing chamber arranged inside a vacuum container. Background Art

[0002] JP Patent Publication No. 2017-143186 (Patent Document 1) discloses an atomic layer level etching process for a layer on a semiconductor wafer. Specifically, first, the following process is performed: active species (free radicals) of a processing gas formed using plasma are supplied to the upper surface of a sample, i.e., a semiconductor wafer, and attached to the surface to generate a product layer. Thereafter, the etching process is performed by removing the product layer formed with a thickness equal to that of the atomic layer through the following process, wherein in the above process, an electromagnetic wave containing an infrared wavelength is irradiated to the wafer from a lamp arranged in a ring shape in an area surrounding the upper portion of the wafer to cause the product layer to be detached and volatilized.

[0003] In such a technology, the following are performed on a wafer placed on a sample stage (carrier) in a processing chamber disposed inside a vacuum container: (1) a step of forming a layer of a reaction product based on free radicals; and (2) a step of removing the reaction layer based on heating by irradiating electromagnetic waves including infrared rays. With regard to the reaction layer generation step (1), first, a processing gas is supplied to a free radical generation space in the upper part of the processing chamber, and free radicals are formed by activating the gas. The formed free radical particles are supplied to the upper surface of the wafer placed in the processing chamber via a gas introduction pipe connected to the lower processing chamber, thereby forming a reaction layer. With regard to the reaction layer removal step (2), after (1), infrared light is irradiated from a lamp disposed on the upper part of the wafer to vaporize the product on the upper surface of the wafer and remove the reaction layer. These steps are repeated alternately to remove the film of the processing object on the surface of the wafer.

[0004] On the other hand, in the etching process, reaction products are generated in various processes, and part of them adhere to or deposit on the wall surface in the processing chamber. If the deposits are released again from the surface inside the processing chamber and adhere to the surface of the wafer again, pattern defects will occur, which may damage the performance of the semiconductor device manufactured from the wafer. In particular, since the products attached to the side wall surface of the carrier are attached near the wafer, they are likely to fly onto the wafer, which is likely to become a factor in reducing the yield of the process.

[0005] Chemical or physical cleaning methods are used to address these problems. As a means of cleaning, the technology disclosed in JP Patent Publication No. 2022-152246 (Patent Document 2) is used. In this technology, an inert gas is introduced from the bottom of the carrier, and it is circulated upward in the gap between the base ring mounted on the dispersion plate and the side wall of the carrier and diffused into the processing chamber. The gas flow is used to suppress the reaction products from being drawn around the side wall and back of the carrier, and the retained foreign matter is removed by heated gas.

[0006] Prior art literature

[0007] Patent Literature

[0008] Patent Document 1: Japanese Patent Application Publication No. 2017-143186

[0009] Patent Document 2: Japanese Patent Application Publication No. 2022-152246 Summary of the invention

[0010] Problems to be solved by the invention

[0011] In the above-mentioned prior art, inert gas is supplied upward from a circumferentially uniform gap between a base ring or a dispersion plate and a stage to suppress the following situation: particles formed in plasma and products formed accompanying the processing of wafers adhere to the surface of the film covering the outer peripheral side wall surface of the wafer mounting surface of the stage, or interact with the outer peripheral edge of the film covering the surface on which the wafer is mounted, thereby suppressing the generation of foreign matter by local consumption. In addition, since the dispersion plate processed under high pressure requires machining accuracy for the flow path of the inert gas, metal such as SUS is used. In order to reduce the bias of the supply of inert gas, the gap between the stage and the stage is positioned so that the deviation in the circumferential direction is within the allowable range, and the position relative to the stage is fixed with screws or bolts.

[0012] The operator adjusts the position of the dielectric susceptor ring disposed above the metal dispersion plate so that the gap between the inner circumference and the outer peripheral side wall of the stage deviates in the circumferential direction. Therefore, an artificial error occurs. Furthermore, the position of the dielectric susceptor ring is not fixed relative to the dispersion plate disposed below due to the difference in thermal expansion, and the gap between the dielectric susceptor ring and the outer peripheral side wall of the stage deviates in the circumferential direction as multiple wafers are processed.

[0013] If the base ring is eccentric and deviates from the position, the deviation in the circumferential direction of the flow rate of the gas supplied from the gap between the base ring and the carrier becomes larger, which in turn hinders the supply of gas. In addition, when processing under high pressure, the deposition atmosphere tends to remain near the carrier in the lower part of the processing chamber, and particles caused by the processing gas adhere to the surface of the carrier, and the adsorption film (especially the end) reacts with the plasma and is consumed, which is easy to produce foreign matter. In particular, in the case of using polyimide as the material of the dielectric film arranged on the upper surface of the carrier in order to electrostatically adsorb the chip on the upper surface of the carrier, it is easy to react with halogen radicals used as a gas supplied to remove (clean) the attached attachments. In such a case, the amount of attachments and consumption on the surface of the carrier increases, and foreign matter will be generated from the carrier. Regarding such a problem, the prior art has not considered it, so problems arise.

[0014] As described above, in the prior art, the edge gas flow path becomes circumferentially non-uniform due to the eccentricity of the susceptor ring, which causes local consumption of the stage surface material and deterioration of the wafer in-plane uniformity.

[0015] An object of the present invention is to provide a wafer processing device that can improve the long-term stable operation and processing efficiency of the carrier even when the base ring is eccentric.

[0016] Means for solving problems

[0017] A wafer processing device according to an embodiment of the present invention is characterized in that it comprises: a processing chamber, which is arranged inside a vacuum container and is supplied with a processing gas inside; a sample stage, which is arranged in the processing chamber, supports a wafer to be processed, and has a cylindrical shape; a step portion, which annularly surrounds a mounting surface of an upper portion of the sample stage on which the wafer is mounted; a gas dispersion plate, which is placed on the bottom surface of the step portion and has a ring shape surrounding the mounting surface; a base ring, which is placed on the upper surface of the gas dispersion plate and surrounds the mounting surface; and a flow path, which is composed of a gap between the bottom surface of the gas dispersion plate and the bottom surface of the step portion, a gap between the inner peripheral side wall of the gas dispersion plate and the outer peripheral side wall of the step portion, and a gap between the inner peripheral side wall of the base ring and the outer peripheral side wall of the step portion, through which an inactive gas flows, and the inner peripheral side wall of the base ring is provided with recesses extending in the up-down direction at multiple locations.

[0018] Effects of the Invention

[0019] According to the present invention, a wafer processing device capable of improving long-term stable operation of a stage and processing efficiency can be provided. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] Figure 1 It is a longitudinal sectional view schematically showing the structure of a wafer processing apparatus according to an embodiment of the present invention.

[0021] Figure 2 It is a longitudinal sectional view schematically showing the structure of a stage gas supply mechanism used in the embodiment.

[0022] Figure 3 It is a cross-sectional view schematically showing the structure of a dispersion plate included in the stage gas introduction mechanism according to the embodiment.

[0023] Figure 4 This is a diagram schematically showing the relationship between the slits of the base ring and the dispersion plate constituting the gas flow path provided in the stage gas introduction mechanism of Example 1.

[0024] Figure 5 This is a schematic diagram showing the relationship between a modified example of the susceptor ring constituting the gas flow path provided in the stage gas introduction mechanism of Example 1 and the slits of the dispersion plate.

[0025] Figure 6 This is a cross-sectional view of a sample stage base material showing a gas flow path constituting the stage gas introduction mechanism of Example 2.

[0026] Figure 7 This is a cross-sectional view showing a modified example of the sample stage base material constituting the gas flow path provided in the stage gas introduction mechanism of Example 2. DETAILED DESCRIPTION

[0027] Hereinafter, embodiments of the present invention will be described using the drawings.

[0028] [Example 1]

[0029] Below, use Figure 1 to Figure 5 Embodiments of the present invention will be described. Figure 1 It is a longitudinal sectional view schematically showing the structure of a wafer processing apparatus according to an embodiment of the present invention.

[0030] Figure 1 The wafer processing apparatus 100 according to the present embodiment shown in the figure comprises: a vacuum container 101; a discharge section 102 constituting the upper part of the vacuum container 101 and forming plasma inside; and a processing chamber 104 constituting the lower part of the vacuum container and comprising a sample stage 103 on which a semiconductor wafer (hereinafter referred to as a wafer) is placed. In other words, the sample stage 103 is a stage on which the semiconductor wafer to be processed is placed on the placing surface of the upper part, and is arranged in the processing chamber 104 inside the vacuum container 101. In addition, the wafer processing apparatus 100 comprises: an IR lamp unit 105 for heating the wafer on the sample stage 103; and a processing chamber internal passage 1030 connecting the discharge section 102 and the processing chamber 104, and comprising a dielectric dispersion plate 106 having a through hole for passing radical particles generated in the plasma.

[0031] In the wafer processing apparatus 100 of the present embodiment, the processing chamber 104 and the discharge section 102 are cylindrical spaces, and the central axes thereof are arranged on the same axis or at a position that can be regarded as being coaxial. The processing chamber 104 and the discharge section 102 arranged above the processing chamber 104 are connected by a processing chamber inner passage 1030, and are separated by a circular dispersion plate 106 arranged inside the processing chamber inner passage 1030, wherein the processing chamber inner passage 1030 is also arranged at a position that is consistent with the central axes of the processing chamber 104 and the discharge section 102 or at a position that can be regarded as being consistent, and has a cylindrical shape. The discharge section 102 and the processing chamber 104 are connected through a plurality of through holes arranged concentrically in the dispersion plate 106, and the gas supplied to the discharge section 102 is excited as described later, flows to the processing chamber 104 below in the processing chamber inner passage 1030, and is supplied to the processing chamber 104 through the through holes of the dispersion plate 106.

[0032] The discharge part 102 flows into the processing gas 1013 to form plasma 1011, and the plasma state is configured to be observed by optical means. In this way, the processing gas supply path is arranged above the sample stage 103, and the processing gas supply path is a supply path including the discharge part 102, and the processing gas 1013 for processing the wafer is supplied into the processing chamber 104.

[0033] The discharge section 102 includes: a cylindrical quartz chamber (dielectric chamber) 107, which constitutes the upper part of the vacuum container 101, and whose interior is connected to the processing chamber 104 and is decompressed; and an ICP coil 108, which is arranged outside the outer peripheral side wall surface of the quartz chamber 107 and is wound multiple times with a gap between the side wall surface. The ICP coil 108 is connected to a high-frequency power supply for plasma generation via a matching device, and the high-frequency power supplied from the high-frequency power supply generates plasma 1011 in the quartz chamber 107 by ICP (Inductively Coupled Plasma: Inductively Coupled Plasma) discharge. The frequency of the high-frequency power uses a frequency band of several tens of MHz such as 13.56MHz.

[0034] A top plate 1014 is provided at the top of the discharge section 102. A dispersion plate 106 and a shower plate are provided at the bottom of the discharge section 102, and a processing gas 1013 is introduced into the vacuum container 101 via the dispersion plate 106 and the shower plate. According to the above, the processing gas 1013 introduced is adjusted to supply flow rate by a mass flow controller provided by each gas type. As the processing gas 1013, a combustible gas, an oxidizing gas, and a mixed gas of these, or a mixed gas of these diluted by an inert gas is used. In addition, the top plate 1014 is placed on the quartz chamber 107 by sandwiching a sealing member such as an O-ring between the back side of its outer peripheral edge portion and the upper end surface of the quartz chamber 107, thereby being installed on the discharge section 102. Thus, the inside of the discharge section 102 is hermetically sealed from the outside of the vacuum container 101.

[0035] At the bottom of the processing chamber 104, an opening for exhaust is provided to reduce the pressure in the vacuum container 101. The vacuum container 101 is connected to a vacuum pump through an exhaust pipe from the opening. A pressure regulating valve is arranged on the path between the opening and the vacuum pump to adjust the flow rate or speed of the exhaust 1017 by increasing or decreasing the flow path cross-sectional area of ​​the path or the opening.

[0036] In the processing chamber 104 , a sample stage 103 on which a wafer 204 is placed is arranged at a position that coincides with or is approximately coincident with the central axis of the discharge section 102 and the processing chamber 104 .

[0037] The IR lamp unit 105 for heating the wafer 204 is arranged above the processing chamber 104 and above the outer peripheral area of ​​the sample stage 103. In addition, it is arranged at a position surrounding the outer periphery of the passage 1030 in the processing chamber. A flow path that serves as a passage for free radicals is provided in the center of the IR lamp unit 105, and a dielectric dispersion plate 106 is provided in the flow path. The dielectric dispersion plate 106 has a plurality of through holes (passages) in a concentric circle shape, shielding ions and electrons generated in the plasma and allowing neutral particles or free radical particles of the gas to pass through. The IR lamp unit 105 is mainly composed of an IR lamp 1020, a reflection plate 1021 for reflecting IR light, and a light transmission window 1022 for transmitting IR light. It has the following structure: the IR lamp 1020 for heating the wafer is provided in the air atmosphere, and the light transmission window 1022 is provided to extend from the lower surface of the IR lamp unit 105 to the outer peripheral side wall surface of the passage 1030 in the processing chamber to divide the reduced pressure atmosphere in the processing chamber 104 and the air atmosphere.

[0038] The IR lamp 1020 uses a circular (circular) lamp. That is, the IR lamp 1020 that irradiates the wafer 204 with electromagnetic waves to heat the wafer 204 is arranged in a ring shape around the above-mentioned processing gas supply path above the sample stage 103. In addition, regarding the light radiated from the IR lamp 1020, light mainly in the visible light to infrared light region (herein referred to as IR light) is emitted. The IR lamp 1020 is connected to a lamp power supply that supplies power. In this embodiment, the near-infrared region of 500nm to 3000nm is used for wafer temperature adjustment, and the far-infrared region after 3000nm is used for IR absorption of the cleaning gas. According to this structure, not only the wafer 204 is heated by the IR lamp 1020 for wafer heating, but also the dispersion plate 106 can be heated by the IR lamp 1020. As a result, since the slit plate for ion shielding is also heated by the light for wafer heating, the amount of free radicals of the deposited film attached to the slit plate is reduced, and the generation of foreign particles caused by the formation of the deposited film is suppressed.

[0039] Although not shown in the figure, the power supplied to the arc-shaped portions of the IR lamps 1020 (three in the figure) arranged on the concentric circles and located at different radii can be independently adjusted, so that the radial distribution of the heating amount of the wafer 204 can be adjusted.

[0040] In the wafer processing apparatus 100 of the present embodiment, the following steps are performed on the wafer 204. Specifically, first, the following steps are performed: (1) forming a reaction product layer based on free radicals on the surface of the wafer 204; and (2) irradiating the surface of the wafer 204 with electromagnetic waves including infrared rays to heat the surface of the wafer 204 and remove the reaction product layer.

[0041] Regarding the step (1) of generating the reaction product layer, first, the processing gas 1013 is supplied into the discharge section 102 and activated to generate the plasma 1011. The generated plasma 1011 is shielded from ions and electrons by the dispersion plate 106, and only radical particles or neutral particles are connected to the lower processing chamber 104, and supplied to the upper surface of the wafer 204 placed in the lower processing chamber 104, thereby forming a reaction product layer. That is, the radical particles or neutral particles of the processing gas 1013 are introduced onto the wafer 204 placed on the mounting surface of the sample stage 103, and the reaction product layer is formed on the surface of the film layer of the processing object formed in advance on the upper surface of the wafer 204. Regarding the step (2) of removing the reaction product layer, it is carried out after the step (1), and infrared light (electromagnetic wave) is irradiated from the IR lamp unit 105 disposed on the upper part of the wafer 204 to vaporize the product on the upper surface of the wafer 204, thereby removing the reaction product layer. These steps are repeated alternately to remove the film to be processed on the surface of the wafer 204 .

[0042] Figure 2 It indicates Figure 11 is a schematic longitudinal cross-sectional view of the structure of the stage gas supply mechanism of the present embodiment. The sample stage 103 shown in this figure has a cylindrical structure coaxial with the central axis of the processing chamber 104, and has an internal sample stage substrate 201 and a sample adsorption film 202 on the upper surface. In addition, the sample stage substrate 201 has an annular step portion surrounding the outer peripheral portion of the upper sample adsorption film 202 surface. A gas distribution plate 208 is placed on the bottom surface of the annular step portion, and a base ring 205 is placed on the upper surface of the gas distribution plate 208.

[0043] In the sample stage base material 201, a coolant flow path 216 for cooling the sample stage 103 is formed inside, and the coolant is circulated and supplied by the refrigerator 215. In addition, in order to fix the chip 204 by electrostatic adsorption, a plate-shaped electrode plate (electrode for electrostatic adsorption) 203 is embedded in the carrier, and each is connected to a DC power supply (power supply for electrostatic adsorption). In addition, in order to efficiently cool the chip 204, He gas can be supplied between the back side of the chip 204 and the sample stage 103. That is, it has the function of fixing and adsorbing the chip 204 and cooling it.

[0044] As the sample adsorption film 202, a resin sheet such as polyimide is attached so that the back of the wafer will not be damaged even if the wafer 204 is kept adsorbed and heated / cooled. In addition, in order to fix the wafer 204 by electrostatic adsorption, a plate-shaped electrode plate 203 is embedded in the sample adsorption film 202, and the electrode plate 203 is connected to a DC power supply. In addition, a groove is provided in the sample adsorption film 202, which serves as a path for supplying He gas between the wafer 204 and the sample adsorption film 202. As a result, the sample stage 103 and the wafer 204, whose temperature is regulated in the coolant path, can be in thermal contact through the He gas, and the wafer 204 heated by the IR lamp assembly 105 can be efficiently cooled.

[0045] A quartz base ring 205 is disposed on the outer periphery of the sample stage 103 to protect the sample stage 103 from corrosion by etching gas. The base ring 205 is cylindrical in shape with the same central axis as the sample stage, and its inner diameter is designed in accordance with the diameter of the side walls of the sample stage substrate 201 and the sample adsorption film 202, and covers the sample stage 103 except for the portion where the wafer 204 is mounted. The base ring 205 contains a light-transmitting material (e.g., quartz). That is, the dielectric base ring 205 surrounds the mounting surface of the sample stage 103 and is disposed on the sample stage 103.

[0046] The gas dispersion plate 208 is located on the upper surface of the annular stepped portion surrounding the outer circumference of the surface of the sample adsorption film 202 on the upper part of the sample stage substrate 201, and the base ring 205 is placed on the upper surface. The base ring 205 is cylindrical with the central axis of the sample stage, and the inner diameter is designed according to the diameter of the convex stage outer peripheral side wall 209 and the side wall of the sample adsorption film 202 generated by the annular stepped portion of the sample stage substrate 201, and covers from the upper surface of the gas dispersion plate 208 to the outer peripheral side wall surface of the sample stage substrate 201. The upper surface of the base ring 205 is designed to be lower than the mounting surface of the sample stage 103 (the upper surface of the sample adsorption film 202), and is designed so that the lower surface of the wafer 204 and the upper surface of the base ring 205 do not contact each other. The base ring 205 contains a light-transmitting material (for example, quartz). That is, the dielectric susceptor ring 205 is arranged on the sample stage 103 so as to surround the mounting surface of the sample stage 103 .

[0047] A carrier gas introduction mechanism 206 is provided below the base ring 205, wherein the carrier gas introduction mechanism 206 is used to remove foreign matter deposited on the side of the sample stage 103 and to suppress the intrusion of foreign matter. The carrier gas introduction mechanism 206 is a mechanism having a carrier internal piping 207 and a gas dispersion plate 208. In addition, the gas supplied from the carrier internal piping 207 introduces a non-volatile gas such as Ar (argon), or a molecular gas containing a bond of CH, OH, NH, C=O, C=C or CO (here referred to as IR absorbing gas). Ar gas is used for the purpose of suppressing the intrusion of reaction products in the process into the side of the carrier. IR absorbing gas can absorb energy efficiently because the stretching vibration and angular vibration of the molecules resonate with the wavelength of IR light, so it can be used in the heating removal of foreign matter.

[0048] The IR light irradiated from the IR lamp assembly 105 has a wavelength in the band absorbed by the gas. For example, when the gas is carbon dioxide, it is desirable that the IR light is in the far infrared region. Specifically, the wavelength of the IR light is desirable to be 10.1 to 14.9 μm or 3.2 to 3.7 μm when the bond of the gas is CH, 2.7 to 3.1 μm in the case of OH, and 2.9 μm in the case of NH. In addition, the wavelength of the IR light is desirable to be 5.5 to 6.5 μm when the bond of the gas is C=O, 6.1 to 6.3 μm in the case of C=C, and 7.7 to 9.6 μm in the case of CO. An IR lamp for irradiating IR light of such a wavelength may be further provided in the IR lamp assembly 105. That is, Figure 1The IR lamp 1020 shown is configured as a lamp for adjusting the chip temperature by irradiating IR light in the near-infrared region (wavelength 0.4 to 3 μm), and an IR lamp for irradiating IR light of the above-mentioned wavelength (above 4 μm) is further configured so as to be arranged outside the three-layer IR lamp 1020 .

[0049] There are eight stages internal piping 207 located inside the sample stage base material 201 at equal intervals in the circumferential direction, and they are arranged directly below the annular downstream gas reservoir 212 formed on the back side of the gas dispersion plate 208. In addition, the stage gas introduction mechanism 206 diffuses the gas supplied from the eight stages internal piping 207 of the mechanism in the annular downstream gas reservoir 212 toward the circumferential direction of the sample stage 103, and diffuses it again in the annular upstream gas reservoir 214 of the subsequent stage through 16 slits (introduction ports) 213 evenly arranged at intervals of 22.5 degrees, and passes through a fine gap 210 (~0.2 mm) between the inner peripheral wall of the base ring 205 placed on the upper surface of the gas dispersion plate 208 and the stage outer peripheral side wall 209, and flows into the processing chamber 104 from the vicinity of the back side of the wafer 204, thereby suppressing the attachment of particles caused by the processing gas to the stage surface, and the adsorption film (especially the end) and plasma reaction and consumption.

[0050] Figure 3 It indicates Figure 2 The cross-sectional view of the relationship between the structure of the gas dispersion plate 208 provided in the stage gas introduction mechanism 206 of the present embodiment and the D-cut portion 404 provided in the sample stage base material 201 is shown. Figure 2 The structure of the annular gas dispersion plate 208 shown is 1 / 4 of the circumference (90 degrees around the center of the ring).

[0051] The gas supplied from the eight stage internal pipes 207 of the stage gas introduction mechanism 206 diffuses in the circumferential direction of the sample stage 103 at the downstream gas reservoir 212 which is an annular space, and diffuses again in the upstream gas reservoir 214 which is an annular space of the subsequent stage through 16 slits (inlet ports) 213 which are evenly arranged at intervals of 22.5 degrees. In this way, a gas flow path (path) is formed in the stage gas introduction mechanism 206 so that the non-volatile gas or the IR absorbing gas is sprayed from the outer peripheral side of the sample stage 103 to the side of the convex portion in the center of the sample stage 103.

[0052] In addition, the gas dispersion plate 208 for processing under high pressure requires machining accuracy for the flow path of the inert gas, so metal such as SUS is used. In addition, in order to reduce the bias in the supply of the inert gas, the fine gap 210 between the gas dispersion plate 208 and the stage outer peripheral side wall 209 is positioned by the D-cut portion 301 on the gas dispersion plate 208 side and the D-cut portion 404 on the sample stage substrate 201 side of the same shape so that the deviation in the circumferential direction is within the allowable range, and on this basis, the position is fixed with screws and bolts relative to the sample stage substrate 201, thereby managing the fine gap 210 between the stage outer peripheral side wall 209 of the sample stage substrate 201 and the gas dispersion plate 208.

[0053] Figure 4 It is a schematic representation of the composition Figure 2 FIG. 2 is a diagram showing a relationship between a recessed portion 401 of a susceptor ring 205 and a slit (introduction port) 213 of a gas dispersion plate 208 in a gas flow path provided in a stage gas introduction mechanism 206 according to the present embodiment.

[0054] The susceptor ring 205 is placed on the upper surface of the gas distribution plate 208 fixed to the stage bolts forming the flow path of the stage gas introduction mechanism 206. In addition, the susceptor ring 205 and the sample stage base 201 have a D-cut portion 403 on the susceptor ring 205 side and a D-cut portion 404 on the sample stage base 201 side, which are provided for alignment in the same shape. By using these, the D-cut portion 403 provided on the inner peripheral wall of the susceptor ring 205 and the D-cut portion 404 located around the wafer mounting surface of the sample stage base 201 are aligned, and the susceptor ring 205 is placed. In addition, the operator uses a skimmy gauge to perform centering after placement, so as to ensure a uniform fine gap 210 in the circumferential direction between the susceptor ring 205 and the sample stage base 201.

[0055] In addition, on the upper surface of the susceptor ring 205, four D-shaped projections 402 having D-cut portions are provided at equal intervals in the circumferential direction on the inner circumference for the purpose of supporting the peripheral edge of the wafer 204 when the wafer 204 is deviated. Furthermore, three or more concave portions 401 are arranged at equal intervals on the inner circumference of the susceptor ring 205 at a position just above the middle position of the slits (inlet ports) 213 of the stage gas introduction mechanism 206, which are evenly arranged at 16 intervals of 22.5° on the gas dispersion plate 208 at the bottom.

[0056] The dielectric base ring 205 disposed above the metal gas dispersion plate 208 is only adjusted by the operator so that the minute gap 210 between the inner peripheral wall and the stage outer peripheral side wall 209 has a smaller deviation in the circumferential direction, and is not fixed in position relative to the gas dispersion plate 208, which is fixed in position relative to the sample stage base material 201 by screws or bolts. Therefore, human error may occur.

[0057] Furthermore, it is assumed that during the heat treatment, the susceptor ring 205 and the gas distribution plate 208 constituting the stage gas introduction mechanism 206 both reach approximately 200° C. due to the heat input, and the quartz susceptor ring 205 expands by 0.01 mm in the outer diameter direction, and the SUS gas distribution plate 208 also expands by 0.5 mm in the outer diameter direction. In other words, it is assumed that as multiple wafers are processed, the susceptor ring 205 becomes eccentric due to the difference in the amount of thermal expansion with the gas distribution plate 208, and the fine gap 210 becomes non-uniform in the circumferential direction, and the flow rate of the stage gas is biased relative to the circumferential direction. However, even if the base ring 205 is eccentric in the orthogonal coordinate system in the X and Y directions, and even if it is in partial contact with the outer peripheral side wall 209 of the carrier, it is possible to prevent the local gas flow of the inactive gas flowing from the fine gap 210 to the processing chamber 104 from being stagnated by providing more than three recesses 401 at equal intervals on the inner peripheral edge of the base ring 205, thereby suppressing the circumferential unevenness of the carrier gas.

[0058] Figure 5 It is a schematic representation Figure 4 FIG. 4 is a diagram showing the relationship between a modified example of the recess 401 of the base ring 205 and the slit (inlet) 213 of the gas distribution plate 208. Figure 4 In the embodiment, recesses 401 are arranged at equal intervals on the inner peripheral edge of the base ring 205 at three locations among the middle positions of the slits (inlet ports) 213 of the stage gas introduction mechanism 206 arranged at 16 locations, but Figure 5 In the embodiment, recesses 401 are arranged at equal intervals on the inner peripheral edge of the base ring 205 at all 16 locations in the middle of the slits (inlet ports) 213 of the stage gas introduction mechanism 206 arranged at 16 locations. Figure 5 In the variation of Figure 4 Compared with the example, the effect of suppressing the circumferential unevenness of the carrier gas can be significantly achieved.

[0059] [Example 2]

[0060] exist Figure 6 , Figure 7 The cross-sectional view shows the structure Figure 2 The illustrated embodiment is a modified example of the sample stage base material 201 of the gas flow path provided in the stage gas introduction mechanism 206 of the present embodiment.

[0061] exist Figure 5In the modified example, three or more recesses 601 extending in the vertical direction are provided at equal intervals in the circumferential direction on the stage peripheral side wall 209 of the sample stage substrate 201 constituting the minute gap 210 of the stage gas introduction mechanism 206. In order to reduce the bias in the stage gas supply, the D-cut portion 301 on the gas dispersion plate 208 side and the D-cut portion 404 on the sample stage substrate 201 side are positioned relative to the upper surface of the sample stage substrate 201 by using the same shape, and then the position is fixed relative to the sample stage substrate 201 by screws and bolts, and the minute gap 210 between the stage peripheral side wall 209 of the sample stage substrate 201 and the gas dispersion plate 208 is managed. In addition, the recess 601 provided on the stage peripheral side wall 209 of the sample stage substrate 201 is arranged in the middle of 16 slits (introduction ports) 213 for the stage gas (inert gas) provided in the gas dispersion plate 208, which are evenly arranged at intervals of 22.5°. Thus, even if the base ring 205 is eccentric in the orthogonal coordinate system in the X and Y directions, local stagnation of the stage gas flow can be prevented, and the circumferential flow rate unevenness can be suppressed. In addition, in the second embodiment, the upper surface of the inner peripheral edge of the base ring 205 has a D-cut portion 403 for alignment, and the upper surface of the other inner peripheral edge has an inner peripheral wall that is smooth in the circumferential direction.

[0062] In addition, you can Figure 7 As shown in the modified example of , convex portions 701 extending in the vertical direction are provided at equal intervals at three or more locations on the stage outer peripheral side wall 209 of the sample stage substrate 201 constituting the minute gap 210 of the stage gas introduction mechanism 206. In addition, the convex portion 701 is provided at the middle of the adjacent slits (inlet ports) 213 for inert gas, which are evenly arranged at 22.5° intervals, of the gas dispersion plate 208 fixed to the sample stage substrate 201 by bolts at four or more locations adjacent and evenly spaced. Thus, even if the base ring 205 is eccentric in the orthogonal coordinate system of the X and Y directions, local stagnation of the gas flow can be prevented, and uneven flow rate in the circumferential direction can be suppressed. In addition, in the method of the second embodiment, the upper surface of the inner peripheral edge portion of the base ring 205 has a D-cut portion 403 for alignment, and has a smooth inner peripheral wall in the circumferential direction.

[0063] As mentioned above, the invention made by the inventors of the present invention has been specifically described based on the embodiments thereof, but the present invention is not limited to the above embodiments and various modifications can be made without departing from the gist thereof.

[0064] Description of Reference Numerals

[0065] 100…wafer processing device, 101…vacuum container, 102…discharge unit, 103…sample stage, 104…processing chamber, 105…IR lamp assembly, 106…dispersion plate, 107…quartz chamber, 108…ICP coil, 201…sample stage substrate, 202…sample adsorption film, 203…electrode plate, 204…wafer, 205…susceptor ring, 206…stage gas introduction mechanism, 207…stage internal piping, 208…gas dispersion plate, 209…stage outer peripheral side wall, 210…micro gap, 212…downstream gas accumulation area, 213…slit (introduction port) , 214…upstream gas storage place, 215…refrigerator, 216…refrigerant flow path, 301…D-cutting part, 401…recess, 402…D-shaped protrusion for countermeasure against chip deviation, 403…D-cutting part, 404…D-cutting part, 601…recess, 701…convex part, 1011…plasma, 1013…processing gas, 1014…top plate, 1017…exhaust, 1020…IR lamp, 1021…reflecting plate, 1022…light transmission window, 1030…inner passage of processing chamber.

Claims

1. A wafer processing device, characterized in that: have: A processing chamber is arranged inside the vacuum container and is supplied with a processing gas inside; A sample stage, which is arranged in the processing chamber, supports a wafer to be processed, and has a cylindrical shape; a step portion annularly surrounding a placement surface on an upper portion of the sample stage on which the wafer is placed; a gas dispersion plate placed on the bottom surface of the step portion and having a ring shape surrounding the placement surface; a base ring placed on the upper surface of the gas dispersion plate and surrounding the placement surface; and a flow path, which is composed of a gap between the bottom surface of the gas dispersion plate and the bottom surface of the step portion, a gap between the inner peripheral side wall of the gas dispersion plate and the outer peripheral side wall of the step portion, and a gap between the inner peripheral side wall of the base ring and the outer peripheral side wall of the step portion, through which an inert gas flows, The base ring has recessed portions extending in the up-down direction at a plurality of locations on the inner peripheral side wall.

2. The wafer processing apparatus according to claim 1, wherein: The recessed portions are provided at least three locations at equal intervals along the inner circumference.

3. The wafer processing apparatus according to claim 1, wherein: The gap between the bottom surface of the gas dispersion plate and the bottom surface of the height difference portion is composed of an annular downstream gas accumulation place, an annular upstream gas accumulation place, and a plurality of slits connecting the downstream gas accumulation place and the upstream gas accumulation place, and the recess is arranged in the middle position of the plurality of slits in the circumferential direction.

4. A wafer processing device, characterized in that: have: A processing chamber is arranged inside the vacuum container and is supplied with a processing gas inside; A sample stage, which is arranged in the processing chamber, supports a wafer to be processed, and has a cylindrical shape; a step portion annularly surrounding a placement surface on an upper portion of the sample stage on which the wafer is placed; a gas dispersion plate placed on the bottom surface of the step portion and having a ring shape surrounding the placement surface; a base ring placed on the upper surface of the gas dispersion plate and surrounding the placement surface; and a flow path, which is composed of a gap between the bottom surface of the gas dispersion plate and the bottom surface of the step portion, a gap between the inner peripheral side wall of the gas dispersion plate and the outer peripheral side wall of the step portion, and a gap between the inner peripheral side wall of the base ring and the outer peripheral side wall of the step portion, through which an inert gas flows, The step portion has recessed portions extending in the up-down direction at a plurality of locations on the outer peripheral side wall.

5. The wafer processing apparatus according to claim 4, wherein: The recessed portions are provided at least three locations at equal intervals along the outer circumference.

6. The wafer processing apparatus according to claim 4, wherein: The gap between the bottom surface of the gas dispersion plate and the bottom surface of the height difference portion is composed of an annular downstream gas accumulation place, an annular upstream gas accumulation place, and a plurality of slits connecting the downstream gas accumulation place and the upstream gas accumulation place, and the recess is arranged in the middle position of the plurality of slits in the circumferential direction.

7. A wafer processing device, characterized in that: have: A processing chamber is arranged inside the vacuum container and is supplied with a processing gas inside; A sample stage, which is arranged in the processing chamber, supports a wafer to be processed, and has a cylindrical shape; a step portion annularly surrounding a placement surface on an upper portion of the sample stage on which the wafer is placed; a gas dispersion plate placed on the bottom surface of the step portion and having a ring shape surrounding the placement surface; a base ring placed on the upper surface of the gas dispersion plate and surrounding the placement surface; and a flow path, which is composed of a gap between the bottom surface of the gas dispersion plate and the bottom surface of the step portion, a gap between the inner peripheral side wall of the gas dispersion plate and the outer peripheral side wall of the step portion, and a gap between the inner peripheral side wall of the base ring and the outer peripheral side wall of the step portion, through which an inert gas flows, The step portion has convex portions extending in the up-down direction at a plurality of locations on the outer peripheral side wall.

8. The wafer processing apparatus according to claim 7, wherein: The convex portions are provided at least three locations at equal intervals along the outer circumference.

9. The wafer processing apparatus according to claim 7, wherein: The gap between the bottom surface of the gas dispersion plate and the bottom surface of the height difference portion is composed of an annular downstream gas accumulation place, an annular upstream gas accumulation place, and a plurality of slits connecting the downstream gas accumulation place and the upstream gas accumulation place, and the protrusion is arranged in the middle position of the plurality of slits in the circumferential direction.

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