Substrate Processing Apparatus and Substrate Processing Method

Abstract

The present invention provides a substrate processing apparatus and a substrate processing method. A technique capable of improving the in-plane uniformity of processing is provided. The substrate processing apparatus according to one aspect of the present disclosure includes: a processing container having a substantially cylindrical shape; a gas nozzle extending in the vertical direction along the inner side of the inner wall of the processing container and forming a gas flow path therein; and a gas ejection unit provided above the processing container, communicating with the gas flow path, distributing the gas introduced from the gas nozzle, and ejecting the gas from the outer peripheral portion of the processing container.

Description

Technical Field

[0001] The present disclosure relates to a substrate processing apparatus and a substrate processing method. Background Art

[0002] There is known a film forming method in which a plurality of wafers are arranged in a processing container, and a film forming raw material gas is supplied along the surfaces of the plurality of wafers from a prescribed position on the side of the plurality of wafers, and a prescribed film is formed on the plurality of wafers by reaction active species generated from the film forming raw material gas (for example, see Patent Document 1). In Patent Document 1, a gas for concentration adjustment is supplied to the surfaces of the plurality of wafers from a position different from the prescribed position.

[0003] Prior Art Documents

[0004] Patent Documents

[0005] Patent Document 1: Japanese Unexamined Patent Application Publication No. 2018-195727 Summary of the Invention

[0006] Problems to be Solved by the Invention

[0007] The present disclosure provides a technique capable of improving in-plane uniformity of processing.

[0008] Solutions for Solving the Problems

[0009] A substrate processing apparatus according to one aspect of the present disclosure includes: a processing container having a substantially cylindrical shape; a gas nozzle extending in the vertical direction along the inner side of the inner wall of the processing container and forming a gas flow path therein; and a gas ejection unit provided above the processing container, communicating with the gas flow path, distributing the gas introduced from the gas nozzle, and ejecting the gas from the outer peripheral portion of the processing container.

[0010] Effects of the Invention

[0011] According to the present disclosure, in-plane uniformity of processing can be improved. Brief Description of the Drawings

[0012] Figure 1 is a schematic diagram showing an example of a substrate processing apparatus according to an embodiment.

[0013] Figure 2 is Figure 1 a sectional view taken along line II-II.

[0014] Figure 3 is a cross-sectional view showing an example of a nozzle support portion.

[0015] Figure 4 It is a perspective view (1) showing an example of a dilution gas ejection part.

[0016] Figure 5 It is a perspective view (2) showing an example of a dilution gas ejection part.

[0017] Figure 6 It is a view when observing the dilution gas ejection part from the side.

[0018] Figure 7 It is a view when observing the dilution gas ejection part from above.

[0019] Figure 8 It is a view when observing the dilution gas ejection part from below.

[0020] Figure 9 It is a magnified perspective view showing Figure 8 a local part.

[0021] Figure 10 It is a view when observing the inner tube from above.

[0022] Figure 11 It is a magnified perspective view showing the fitting part of the dilution gas ejection part.

[0023] Figure 12 It is a magnified cross-sectional view showing the fitting part of the dilution gas ejection part.

[0024] Figure 13 It is a magnified cross-sectional view showing the ejection part of the dilution gas ejection part.

[0025] Figure 14 It is a perspective view showing the appearance of the distribution part of the dilution gas ejection part.

[0026] Figure 15 It is a perspective cross-sectional view showing the inside of the distribution part of the dilution gas ejection part.

[0027] Figure 16 It is a diagram (1) for explaining the flow of the dilution gas.

[0028] Figure 17 It is a diagram (2) for explaining the flow of the dilution gas.

[0029] Figure 18 It is a diagram for explaining the analysis model.

[0030] Figure 19 It is a diagram showing the numerical analysis result of the film formation rate in the plane of the wafer.

[0031] Figure 20 It is a diagram showing the numerical analysis result of the film thickness uniformity in the plane of the wafer. Detailed implementation mode

[0032] Hereinafter, with reference to the accompanying drawings, a non-limiting exemplary embodiment of the present disclosure will be described. In all the drawings, the same or corresponding components or parts are denoted by the same or corresponding reference numerals, and repeated descriptions are omitted.

[0033] 〔Substrate processing apparatus〕

[0034] Refer to Figures 1 to 3 An example of the substrate processing apparatus according to the embodiment will be described. Figure 1 FIG. is a schematic diagram showing an example of the substrate processing apparatus according to the embodiment. Figure 2 is Figure 1 A sectional view taken along line II-II of Figure 3 FIG. is a sectional view showing an example of the nozzle support portion.

[0035] The substrate processing apparatus 1 includes a processing container 10, a gas supply unit 30, an exhaust unit 50, a heating unit 70, a dilution gas ejection unit 100, and a control unit 90.

[0036] The processing container 10 houses the boat 16. The boat 16 holds a plurality of substrates substantially horizontally at intervals in the vertical direction. The substrate may be, for example, a semiconductor wafer (hereinafter referred to as "wafer W"). The processing container 10 has an inner tube 11 and an outer tube 12. The inner tube 11 is also referred to as an inner cylinder and is formed in a substantially cylindrical shape with a top and an open bottom. The top 11a of the inner tube 11 is formed flat, for example. The outer tube 12 is also referred to as an outer cylinder and is formed in a substantially cylindrical shape with a top and an open bottom that covers the outside of the inner tube 11. The inner tube 11 and the outer tube 12 are arranged coaxially to form a double-tube structure. The inner tube 11 and the outer tube 12 are formed of a heat-resistant material such as quartz, for example.

[0037] On one side of the inner tube 11, a housing portion 13 for housing a gas nozzle is formed along its longitudinal direction (vertical direction). For the housing portion 13, for example Figure 2 As shown, a convex portion 14 is formed by causing a part of the side wall of the inner tube 11 to protrude outward, and the inside of the convex portion 14 is formed as the housing portion 13. Opposite to the housing portion 13, a rectangular opening 15 is formed along the longitudinal direction (vertical direction) on the side wall of the inner tube 11 on the opposite side. The opening 15 is a gas discharge port formed so as to be able to discharge the gas inside the inner tube 11. The opening 15 is formed by extending in the vertical direction such that the length of the opening 15 is the same as or longer than the length of the boat 16.

[0038] The lower end of the processing container 10 is supported by a manifold 17 having a substantially cylindrical shape formed of, for example, stainless steel. A flange 18 is formed at the upper end of the manifold 17, and the lower end of the outer tube 12 is disposed on the flange 18 to support it. A sealing member 19 such as an O-ring is sandwiched between the lower end of the outer tube 12 and the flange 18 to make the inside of the outer tube 12 airtight.

[0039] An annular support portion 20 is provided on the inner wall of the upper portion of the manifold 17, and the lower end of the inner tube 11 is disposed on the support portion 20 to support it. A lid 21 is hermetically attached to the opening at the lower end of the manifold 17 by a sealing member 22 such as an O-ring, and the opening at the lower end of the processing container 10, that is, the opening of the manifold 17, is hermetically closed. The lid 21 is formed of, for example, stainless steel.

[0040] A rotary shaft 24 is provided through the center of the lid 21 by a magnetic fluid seal 23, and the rotary shaft 24 supports the boat 16 so as to be rotatable. The lower portion of the rotary shaft 24 is rotatably supported by an arm 25A of a lifting mechanism 25 constituted by a boat lifting mechanism.

[0041] A rotary plate 26 is provided at the upper end of the rotary shaft 24, and the boat 16 for holding the wafer W is placed on the rotary plate 26 via a quartz heat insulating table 27. Therefore, by raising and lowering the lifting mechanism 25, the lid 21 and the boat 16 move up and down integrally, and the boat 16 can be inserted and removed with respect to the inside of the processing container 10.

[0042] A gas supply unit 30 is attached to the manifold 17. The gas supply unit 30 includes a dilution gas nozzle 32, a nozzle support portion 33, and a plurality (for example, seven) of processing gas nozzles 31a to 31g.

[0043] As Figure 2 shown, the processing gas nozzles 31a to 31g are located in a housing portion 13 inside the inner wall of the inner tube 11, and are arranged at intervals along the circumferential direction in a row. In addition, in Figure 1 the illustration of the processing gas nozzles 31b to 31g is omitted. Each of the processing gas nozzles 31a to 31g extends along the length direction (vertical direction) of the inner tube 11 inside the inner wall of the inner tube 11, and the lower end is inserted into the nozzle support portion 33. Each of the processing gas nozzles 31a to 31g is a straight tube having a circular cross section and is formed of, for example, quartz. The tip (upper end) of each of the processing gas nozzles 31a to 31g is closed, and an opening is provided at the base end (lower end). A plurality of gas holes 36a to 36g are provided at a predetermined interval along the length direction of each of the processing gas nozzles 31a to 31g. The plurality of gas holes 36a to 36g face, for example, the center side of the inner tube 11 (wafer W side).

[0044] The processing gas nozzles 31a to 31g jet various processing gases introduced from a processing gas supply source 34 toward a plurality of wafers W mounted on a boat 16 through a plurality of gas holes 36a to 36g. As the various processing gases, for example, film-forming gases such as source gases containing silicon or metal, and reactive gases containing oxygen or nitrogen can be cited.

[0045] As Figure 2 shown, a dilution gas nozzle 32 is located in a housing portion 13 inside the inner wall of the inner tube 11, and is disposed at a circumferential interval from the processing gas nozzle 31g. The dilution gas nozzle 32 extends along the length direction of the inner tube 11 inside the inner wall of the inner tube 11, and the upper end thereof is fitted into a fitting portion 121 of a dilution gas ejection portion 100, and the lower end is inserted into a nozzle support portion 33. The dilution gas nozzle 32 is a straight tube having a circular cross section, and is formed of, for example, quartz. The dilution gas nozzle 32 has an opening 32a (refer to Figure 3 ) at the base end (lower end), and an opening 32b (refer to Figure 12 ) at the top end (upper end).

[0046] The dilution gas nozzle 32 allows the dilution gas introduced from a dilution gas supply source 35 to flow through the fitting portion 121 to the dilution gas ejection portion 100. As the dilution gas, for example, inert gases such as nitrogen and argon can be cited. In addition, the dilution gas ejection portion 100 will be described later.

[0047] As Figure 3 shown, the nozzle support portion 33 is provided to penetrate the processing container 10, and supports the lower ends of the processing gas nozzles 31a to 31g and the dilution gas nozzle 32 inside the processing container 10. The nozzle support portion 33 includes a gas flow path 33a for allowing gas to flow inside. The gas flow path 33a allows the various processing gases introduced from the processing gas supply source 34 to flow to the processing gas nozzles 31a to 31g, and allows the dilution gas introduced from the dilution gas supply source 35 to flow to the dilution gas nozzle 32.

[0048] An exhaust portion 50 discharges the gas that is discharged from inside the inner tube 11 through the opening 15 and then discharged from a gas outlet 51 through a space P1 between the inner tube 11 and the outer tube 12. The gas outlet 51 is formed on the upper side wall of the manifold 17, and is above the support portion 20. An exhaust passage 52 is connected to the gas outlet 51. A pressure regulating valve 53 and a vacuum pump 54 are sequentially provided in the exhaust passage 52, and the inside of the processing container 10 can be evacuated.

[0049] A heating portion 70 is provided around the outer tube 12. The heating portion 70 is provided, for example, on a bottom plate 28. The heating portion 70 has a substantially cylindrical shape so as to cover the outer tube 12. The heating portion 70 includes, for example, a heating element and heats the wafers W inside the processing container 10.

[0050] The control unit 90 controls the operations of the respective parts of the substrate processing apparatus 1. The control unit 90 can be, for example, a computer. A program of the computer for operating the respective parts of the substrate processing apparatus 1 is stored in a storage medium. The storage medium can be, for example, a floppy disk, an optical disk, a hard disk, a flash memory, a DVD, or the like.

[0051] 〔Dilution gas ejection unit〕

[0052] Refer to Figures 4 to 15 , and an example of the dilution gas ejection unit 100 included in the substrate processing apparatus 1 of the embodiment will be described. Figure 4 FIG. is a perspective view showing an example of the dilution gas ejection unit 100, showing a state in which the dilution gas ejection unit 100 is mounted on the inner tube 11. Figure 5 FIG. is a perspective view showing an example of the dilution gas ejection unit 100, showing a state in which the dilution gas ejection unit 100 is removed from above the inner tube 11. Figure 6 FIG. is a view when observing the dilution gas ejection unit 100 from the side. Figure 7 FIG. is a view when observing the dilution gas ejection unit 100 from above. Figure 8 FIG. is a view when observing the dilution gas ejection unit 100 from below.

[0053] The dilution gas ejection unit 100 is provided above the inner tube 11. The dilution gas ejection unit 100 distributes the dilution gas introduced from the dilution gas nozzle 32 and ejects it from the outer peripheral portion of the inner tube 11 into the inner tube 11. The dilution gas ejection unit 100 includes a lid 110, an inflow portion 120, an outflow portion 130, and a distribution portion 140.

[0054] The lid 110 has a disk shape larger than the top portion 11a of the inner tube 11 and is mounted above the inner tube 11. A position-limiting portion 111 is provided on the lower surface of the lid 110. Figure 9 FIG. is an enlarged perspective view showing Figure 8 a partial part.

[0055] The position-limiting portion 111 includes a plurality (for example, three) of protrusions 111a to 111c. The plurality of protrusions 111a to 111c are arranged at intervals along the circumferential direction of the lid 110. Each of the protrusions 111a to 111c extends downward from the lower surface of the lid 110 and extends in an arc shape along the circumferential direction of the lid 110. Each of the protrusions 111a to 111c is arranged at a position slightly outside the outer peripheral portion of the top portion 11a of the inner tube 11. Thus, when the lid 110 is mounted on the inner tube 11, the inner surfaces of the protrusions 111a to 111c come into contact with the outer wall of the top portion 11a of the inner tube 11, and the position of the lid 110 relative to the inner tube 11 is limited.

[0056] The inflow portion 120 includes a fitting portion 121 and a horizontal portion 122. Figure 10This is a view when observing the inner tube 11 from above. Figure 11 This is a perspective view showing the fitting portion 121 of the dilution gas ejection portion 100 in an enlarged manner. Figure 12 This is a cross-sectional view showing the fitting portion 121 of the dilution gas ejection portion 100 in an enlarged manner.

[0057] The fitting portion 121 has a substantially cylindrical shape with a closed upper end and an open lower end, and is provided through the top 11a of the inner tube 11 and the cover 110. The fitting portion 121 is formed at the same position as the through-hole 11b formed in the top 11a of the inner tube 11 when viewed from above, and is configured such that the lower end can be fitted with the through-hole 11b. The tip of the dilution gas nozzle 32 is inserted into the fitting portion 121. An opening (not shown) is formed at a position on the center side of the fitting portion 121 closer to the cover 110.

[0058] The horizontal portion 122 extends in the horizontal direction along the radial direction of the cover 110. One end of the horizontal portion 122 is connected to the fitting portion 121, and the inside is communicated with the inside of the dilution gas nozzle 32 through the opening of the fitting portion 121. The other end of the horizontal portion 122 is connected to the distribution portion 140.

[0059] The inflow portion 120 forms an inflow path through which the dilution gas introduced from the dilution gas nozzle 32 flows to the distribution portion 140 by using the fitting portion 121 and the horizontal portion 122. In addition, the fitting portion 121 and the horizontal portion 122 are formed of a heat-resistant material such as quartz, for example.

[0060] The outflow portion 130 includes a plurality of (for example, 4) horizontal portions 131a to 131d and a plurality of (for example, 4) ejection portions 132a to 132d. Figure 13 This is a cross-sectional view showing the ejection portion 132a of the dilution gas ejection portion 100 in an enlarged manner.

[0061] The plurality of horizontal portions 131a to 131d extend in the horizontal direction to the outer peripheral portion of the cover 110 in a radially spreading manner with the distribution portion 140 as the center. One end of each of the horizontal portions 131a to 131d is connected to the distribution portion 140, and the other end is connected to the ejection portions 132a to 132d.

[0062] Each ejection part 132a to 132d is formed, for example, in a tubular shape with the upper and lower ends closed, penetrates through the top 11a of the inner tube 11 and the lid 110 from the other ends of the horizontal parts 131a to 131d, and extends downward. The lower ends of the ejection parts 132a to 132d are inserted into the convex part 11c formed by locally protruding the side wall outward in the upper part of the inner tube 11. An opening 11d is formed in the convex part 11c, and the ejection parts 132a to 132d are inserted into the convex part 11c via the opening 11d. The ejection parts 132a to 132d are extended in a partial height region including the upper part of the inner tube 11, for example, in a height region including a plurality of wafers W mounted on the upper part of the boat 16. A plurality of (for example, 4) gas holes 133a to 133d are formed at intervals along the length direction in each of the ejection parts 132a to 132d. The plurality of gas holes 133a to 133d are, for example, directed toward the center side (wafer W side) of the lid 110.

[0063] The outflow part 130 forms a plurality of outflow paths for ejecting the dilution gas introduced from the distribution part 140 into the inner tube 11 by using the horizontal parts 131a to 131d, the ejection parts 132a to 132d, and the gas holes 133a to 133d. In addition, the horizontal parts 131a to 131d and the ejection parts 132a to 132d are formed of a heat-resistant material such as quartz, for example.

[0064] The distribution part 140 has an annular shape and forms a distribution path inside. Figure 14 It is a perspective view showing the appearance of the distribution part 140 of the dilution gas ejection part 100. Figure 15 It is a perspective sectional view showing the inside of the distribution part 140 of the dilution gas ejection part 100. A plurality of (for example, 5) openings 141 are formed in the outer wall of the distribution part 140, and the horizontal part 122 and a plurality of horizontal parts 131a to 131d are connected to the plurality of openings 141. Thus, the inflow path and the distribution path communicate with each other via the plurality of openings 141, and the distribution path communicates with the plurality of outflow paths. The distribution part 140 is formed of a heat-resistant material such as quartz, for example.

[0065] Refer to Figure 16 and Figure 17 , and explain the flow of the dilution gas ejected into the processing container 10 by the dilution gas ejection part 100. Figure 16 It is a view for explaining the flow of the dilution gas, and is a view when observing the inner tube 11 and the dilution gas ejection part 100 from the side. Figure 17 It is a view for explaining the flow of the dilution gas, and is a view when observing the inner tube 11 and the dilution gas ejection part 100 from above.

[0066] As Figure 16As shown by the arrow F1, the dilution gas introduced from the dilution gas supply source 35 into the dilution gas nozzle 32 flows upward from the lower direction within the dilution gas nozzle 32 and is introduced into the dilution gas ejection section 100.

[0067] As Figure 17 As shown by the arrow F2, the dilution gas introduced into the dilution gas ejection section 100 is introduced into the horizontal section 122 via the fitting section 121, flows from the outer peripheral portion to the center side within the inflow path in the horizontal section 122, and is introduced into the distribution path within the distribution section 140.

[0068] As Figure 17 As shown by the arrow F3, the dilution gas introduced into the distribution path is distributed to a plurality of outflow paths within the horizontal sections 131a to 131d and flows from the center side to the outer peripheral portion within the plurality of outflow paths. Then, as Figure 16 As shown by the arrow F4, the dilution gas flows downward from the upper direction within the outflow paths in the ejection sections 132a to 132d and is ejected into the inner tube 11 from the plurality of gas holes 133a to 133d.

[0069] In this way, according to the dilution gas ejection section 100, the dilution gas is supplied along the surfaces of the plurality of wafers W from the sides of the plurality of wafers W mounted on the upper portion of the boat 16 housed within the inner tube 11.

[0070] In addition, in the substrate processing apparatus 1 of the embodiment, when forming a film by supplying various processing gases from the sides of the plurality of wafers W mounted on the boat 16 housed within the inner tube 11, there is a case where the film thickness of the wafer W mounted on the upper portion of the boat 16 is thicker at the outer peripheral portion than at the central portion. Thus, in the embodiment, when supplying various processing gases, the dilution gas ejection section 100 is used to supply the dilution gas along the surfaces of the plurality of wafers W from the sides of the plurality of wafers W mounted on the upper portion of the boat 16. As a result, at the outer peripheral portion of the wafer W, the various processing gases are diluted by the dilution gas, and the concentration of the processing gases at the outer peripheral portion of the wafer W is reduced. Therefore, it is possible to suppress the film thickness at the outer peripheral portion of the wafer W from being thicker than the film thickness at the central portion. As a result, it is possible to improve the in-plane uniformity of the film thickness of the film formed on the wafer W.

[0071] In addition, according to the substrate processing apparatus 1 of the embodiment, since the dilution gas ejection section 100 includes a plurality of ejection sections 132a to 132b, even when ejecting the dilution gas from a plurality of positions on the side of the wafer W, the number of dilution gas nozzles 32 can be set to one. Therefore, compared with the case where the dilution gas ejection section 100 is not provided, the number of dilution gas nozzles 32 can be reduced to 1 / 4.

[0072] 〔Substrate Processing Method〕

[0073] For the substrate processing method of the embodiment, taking the method of forming a silicon nitride film on the wafer W by chemical vapor deposition (CVD) using the above-described substrate processing apparatus 1 as an example will be described.

[0074] First, the control unit 90 controls the lifting mechanism 25 to send the boat 16 holding a plurality of wafers W into the processing container 10, and airtightly closes the opening at the lower end of the processing container 10 using the lid 21 to perform sealing.

[0075] Next, the control unit 90 performs the following steps: ejecting hexachloroethyldisilane (HCD) gas from at least one of the process gas nozzles 31a to 31g into the processing container 10, and ejecting ammonia gas from at least one other process gas nozzle into the processing container 10. The HCD gas and ammonia gas are an example of the process gas. In addition, the control unit 90 performs the following steps: distributing the dilution gas introduced into the dilution gas ejection unit 100 via the dilution gas nozzle 32 in the dilution gas ejection unit 100, and ejecting it from the outer peripheral portion of the upper part of the processing container 10. Nitrogen is an example of the dilution gas. Thus, while ejecting nitrogen from the dilution gas ejection unit 100, and ejecting HCD gas and ammonia gas from the process gas nozzles 31a to 31g, a silicon nitride film is formed on the wafer W.

[0076] Next, the control unit 90 stops the ejection of the HCD gas, ammonia gas, and nitrogen gas, and controls the lifting mechanism 25 to send the boat 16 out of the processing container 10.

[0077] As described above, according to the substrate processing method of the embodiment, while ejecting nitrogen from the dilution gas ejection unit 100, and ejecting HCD gas and ammonia gas from the process gas nozzles 31a to 31g, a silicon nitride film is formed on the wafer W. Thereby, on the outer peripheral portion of the wafer W, various process gases are diluted by the dilution gas, and the concentration of the process gas on the outer peripheral portion of the wafer W is reduced. Therefore, it is possible to suppress the film thickness on the outer peripheral portion of the wafer W from being thicker than the film thickness at the center portion. As a result, it is possible to improve the in-plane uniformity of the film thickness of the film formed on the wafer W.

[0078] In addition, the time period during which the dilution gas is ejected from the dilution gas ejection unit 100 may be, for example, the entire time period during which the HCD gas and ammonia gas are ejected, or a part of the time period during which the HCD gas and ammonia gas are ejected.

[0079] 〔Example〕

[0080] In an embodiment, while nitrogen gas was ejected from the dilution gas ejection unit 100 of the substrate processing apparatus 1 according to the embodiment, hexachloroethylsilane (HCD) gas and ammonia gas were ejected from the processing gas nozzle, and a numerical analysis was performed on the film thickness when a silicon nitride film was formed. Nitrogen gas is an example of a dilution gas, and HCD gas and ammonia gas are examples of processing gases. In the numerical analysis, general-purpose fluid analysis software (Fluent) manufactured by Ansys Corporation was used.

[0081] Figure 18 This is a diagram for explaining the analysis model. As Figure 18 shown, as an embodiment, an analysis model in which gas nozzles P1 to P5 and gas ejection units P11 to P14 are disposed in the inner tube 11 was prepared.

[0082] The gas nozzles P1 to P5 are disposed at intervals along the circumferential direction in the housing portion 13 inside the inner wall of the inner tube 11, and are set to eject gas toward the center of the wafer W.

[0083] The gas ejection units P11 and P14 are disposed on the outer peripheral portion of the inner tube 11 on the side opposite to the side where the housing portion 13 is formed, and are set to eject gas toward the center of the wafer W. In addition, the gas ejection unit P11 and the gas ejection unit P14 are disposed at positions symmetric with respect to the radial line L connecting the center in the circumferential direction of the housing portion 13 and the center WC of the wafer W.

[0084] The gas ejection units P12 and P13 are disposed on the outer peripheral portion of the inner tube 11 on the side where the housing portion 13 is formed, and are set to eject gas toward the center of the wafer W. In addition, the gas ejection unit P12 and the gas ejection unit P13 are arranged at positions symmetric with respect to the radial line L.

[0085] In Example 1, the film thickness of the silicon nitride film formed by ejecting nitrogen gas from the four gas ejection units P11 to P14 respectively, ejecting nitrogen gas from the gas nozzle P1, ejecting HCD gas / nitrogen gas from the gas nozzle P2, and ejecting ammonia gas from the gas nozzle P3 was calculated. Among them, the flow rate of nitrogen gas ejected from the gas ejection units P11 to P14 was set to 50 sccm. In addition, the flow rate of nitrogen gas ejected from the gas nozzle P1 was set to 500 sccm, the flow rate of HCD gas / nitrogen gas ejected from the gas nozzle P2 was set to 300 sccm / 5000 sccm, and the flow rate of ammonia gas ejected from the gas nozzle P3 was set to 2500 sccm.

[0086] In Example 2, the film thickness of the silicon nitride film formed by ejecting nitrogen gas from two gas ejection parts P12 and P13 respectively, ejecting nitrogen gas from gas nozzle P1, ejecting HCD gas / nitrogen gas from gas nozzle P2, and ejecting ammonia gas from gas nozzle P3 was calculated. Among them, the flow rates of the gases ejected from gas ejection parts P12 and P13 and gas nozzles P1 to P3 were set to the same flow rates as those in Example 1.

[0087] In Comparative Example 1, the film thickness of the silicon nitride film formed by not ejecting nitrogen gas from four gas ejection parts P11 to P14, but ejecting nitrogen gas from gas nozzle P1, ejecting HCD gas / nitrogen gas from gas nozzle P2, and ejecting ammonia gas from gas nozzle P3 was calculated. Among them, the flow rates of the gases ejected from gas nozzles P1 to P3 were set to the same flow rates as those in Example 1.

[0088] In addition, based on the film thicknesses of the silicon nitride films calculated in Example 1, Example 2, and Comparative Example 1, the film formation rate and the film thickness uniformity in the plane of the wafer W were calculated.

[0089] Figure 19 is a graph showing the numerical analysis results of the film formation rate in the plane of the wafer W. In Figure 19 , the horizontal axis represents the wafer position [mm], and the vertical axis represents the film formation rate [a.u.]. Regarding the wafer position, the center of the wafer W was set to 0 mm, and the outer periphery of the wafer W was set to ±150 mm. In Figure 19 , the solid line, the dashed line, and the dotted line respectively represent the numerical analysis results of the film formation rates in Example 1, Example 2, and Comparative Example 1.

[0090] As Figure 19 shown, it can be seen that in Comparative Example 1 (refer to the dotted line), the film thickness of the outer peripheral part of the wafer W is thicker than that of the central part. In contrast, it can be seen that in Example 1 (refer to the solid line) and Example 2 (refer to the dashed line), compared with Comparative Example 1 (refer to the dotted line), the film thickness of the outer peripheral part of the wafer W is thinner, and the film thickness difference between the outer peripheral part and the central part of the wafer W is smaller.

[0091] Figure 20 is a graph showing the numerical analysis results of the film thickness uniformity in the plane of the wafer W. In Figure 20 , the numerical analysis results of the uniformity [%] in Comparative Example 1, Example 1, and Example 2 are shown in order from the left. Among them, the value [%] obtained by dividing the difference between the maximum value and the minimum value in the graph of Figure 19 by the average value was set as the uniformity [%].

[0092] As Figure 20 shown, it can be seen that the uniformity in Comparative Example 1 is about 30%, and in contrast, the uniformity in Example 1 and Example 2 is 10% or less.

[0093] Based on the above results, it can be said that in Example 1 and Example 2, compared with Comparative Example 1, the in-plane uniformity of the film thickness can be improved. That is, it can be said that by supplying the dilution gas along the surfaces of the plurality of wafers W from the side of the wafer W when supplying the processing gas (HCD gas and ammonia gas), the in-plane uniformity of the film thickness of the film (silicon nitride film) formed on the wafer W can be improved.

[0094] In addition, in the above-described embodiment, the dilution gas nozzle 32 is an example of the gas nozzle, and the dilution gas ejection unit 100 is an example of the gas ejection unit.

[0095] It should be considered that the embodiments disclosed this time are illustrative in all aspects and not restrictive. The above-described embodiments can also be omitted, replaced, and changed in various forms without departing from the appended claims and their gist.

[0096] In the above-described embodiment, the case where the processing gas nozzle and the dilution gas nozzle are straight pipes is taken as an example for description, but the present disclosure is not limited thereto. For example, the processing gas nozzle and the dilution gas nozzle may also be L-shaped pipes that are bent in an L shape at the lower part and penetrate the side wall of the outer pipe.

[0097] In the above-described embodiment, the case where a dilution gas ejection unit 100 for distributing and ejecting the dilution gas is provided in the processing container 10 is taken as an example for description, but the present disclosure is not limited thereto. For example, instead of the dilution gas ejection unit 100, a processing gas ejection unit for distributing and ejecting the processing gas may be provided in the processing container 10. In addition, a processing gas ejection unit may be provided in addition to the dilution gas ejection unit 100.

[0098] In the above-described embodiment, the substrate processing apparatus 1 including seven processing gas nozzles 31a to 31g and one dilution gas nozzle 32 is taken as an example for description, but the present disclosure is not limited thereto. For example, the number of processing gas nozzles may be one, two to six, eight or more, and the number of dilution gas nozzles may be two or more. In the case where the number of dilution gas nozzles is two or more, the fitting portion and the horizontal portion included in the inflow portion may be provided corresponding to the number of dilution gas nozzles.

[0099] In the above-described embodiment, the case where the dilution gas is ejected from the dilution gas ejection unit 100 to dilute the film-forming gas when forming a film on the wafer W using the film-forming gas is taken as an example for description, but the present disclosure is not limited thereto. For example, the dilution gas may also be ejected from the dilution gas ejection unit 100 to dilute the etching gas when etching the film using the etching gas.

Claims

1. A substrate processing apparatus, wherein, the substrate processing apparatus includes: a processing container having a substantially cylindrical shape; a processing gas nozzle extending in the vertical direction along the inner side of the inner wall of the processing container, and a plurality of gas holes are formed in the length direction of the processing gas nozzle, wherein the processing gas nozzle ejects the processing gas from the plurality of gas holes toward the center side of the processing container; a dilution gas nozzle extending in the vertical direction along the inner side of the inner wall of the processing container, disposed at an interval from the processing gas nozzle, and a gas flow path for the dilution gas for diluting the processing gas is formed therein; and a dilution gas ejection part provided above the processing container, communicating with the gas flow path, distributing the dilution gas introduced from the dilution gas nozzle and ejecting it from the outer peripheral part of the processing container toward the center side of the processing container.

2. The substrate processing apparatus according to claim 1, wherein, the dilution gas ejection part includes: an inflow part forming an inflow path communicating with the gas flow path; an outflow part forming a plurality of outflow paths for ejecting the dilution gas into the processing container; and a distribution part forming a distribution path for communicating the inflow path with the plurality of outflow paths.

3. The substrate processing apparatus according to claim 2, wherein, the inflow part includes: a fitting part into which the upper part of the dilution gas nozzle is inserted; and a horizontal part having one end connected to the fitting part and the other end connected to the distribution part.

4. The substrate processing apparatus according to claim 2 or 3, wherein, the outflow part includes: a horizontal part having one end connected to the distribution part and the other end extending along the radial direction of the processing container to the outer peripheral part of the processing container; and an ejection part extending downward from the other end of the horizontal part of the outflow part and having gas holes formed therein.

5. The substrate processing apparatus according to claim 4, wherein, the ejection part extends in a partial height region including the upper part of the processing container.

6. The substrate processing apparatus according to claim 2 or 3, wherein, the dilution gas ejection part includes a cover provided above the processing container and having a disc shape, the inflow part, the outflow part, and the distribution part are mounted on the cover.

7. The substrate processing apparatus according to claim 6, wherein, the distribution part is disposed at the center of the cover.

8. The substrate processing apparatus according to claim 6, wherein, a position limiting part is provided on the cover, and the position limiting part limits the position of the cover relative to the processing container.

9. The substrate processing apparatus according to claim 8, wherein, the position limiting part extends downward from the lower surface of the cover and extends in an arc shape along the circumferential direction of the cover.

10. The substrate processing apparatus according to claim 2 or 3, wherein, the distribution part has an annular shape.

11. A substrate processing method, wherein, the substrate processing method has the following steps: Processing gas is ejected from the plurality of gas holes of a processing gas nozzle that extends vertically along the inner side of the inner wall of a processing container having a substantially cylindrical shape and has a plurality of gas holes formed in the longitudinal direction toward the center side of the processing container; and Above the processing container, dilution gas for diluting the processing gas introduced from a dilution gas nozzle is distributed and ejected from the outer peripheral portion of the upper portion of the processing container toward the center side of the processing container, wherein the dilution gas nozzle extends vertically along the inner side of the inner wall of the processing container, is disposed at a space from the processing gas nozzle, and forms a gas flow path for the dilution gas inside.

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