Processing device and processing method

Abstract

To provide a technology that can expand the range of adjustment for the in-plane distribution of film thickness.SOLUTION: A processing device according to an embodiment of the present disclosure includes a processing vessel having a substantially cylindrical shape and an exhaust slit formed in a side wall, and a plurality of gas nozzles extending vertically along the inside of the side wall of the processing vessel and symmetrically arranged with respect to a line connecting the center of the processing vessel and the center of the exhaust slit, and each of which ejects the same processing gas into the processing vessel.SELECTED DRAWING: Figure 2

Description

[Technical Field]

[0001] The present disclosure relates to a processing device and a processing method. [Background technology]

[0002] A film forming apparatus is known that has a gas dispersion nozzle that extends vertically along the inside of the side wall of a cylindrical processing vessel and has multiple gas discharge holes formed over a vertical length corresponding to the wafer support range of a wafer boat (see, for example, Patent Documents 1 and 2). [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Laid-Open No. 2011-135044 [Patent Document 2] Japanese Patent Application Laid-Open No. 2016-181545 Summary of the Invention [Problem to be solved by the invention]

[0004] The present disclosure provides a technique that can expand the range of adjustment of the in-plane distribution of film thickness. [Means for solving the problem]

[0005] A processing apparatus according to one aspect of the present disclosure includes a processing vessel having a substantially cylindrical shape and an exhaust slit formed in a sidewall, the processing vessel accommodating a substrate therein; a plurality of gas nozzles extending vertically along the inside of the sidewall of the processing vessel and arranged symmetrically with respect to a line connecting a center of the processing vessel and a center of the exhaust slit, the plurality of gas nozzles supplying the same processing gas into the processing vessel; flow rate controllers adjusting the flow rates of the processing gas supplied from the plurality of gas nozzles; and a control unit controlling the flow rate controllers; the processing gas is a silicon-containing gas, and the control unit controls to form a silicon oxide film on the substrate by atomic layer deposition; The control unit When forming the silicon oxide film,A film is formed on the substrate by changing a flow rate distribution of the processing gas supplied from the plurality of gas nozzles while keeping the total flow rate of the processing gas supplied from the plurality of gas nozzles fixed. Silicon oxide The film thickness distribution is controlled. [Effects of the Invention]

[0006] According to the present disclosure, the range of adjustment of the in-plane distribution of film thickness can be expanded. [Brief explanation of the drawings]

[0007] [Figure 1] 1 is a schematic diagram illustrating an example of a processing apparatus according to an embodiment; [Figure 2] Schematic diagram showing an example of gas nozzle arrangement [Figure 3] Figure showing the film formation results when Si2H6 is supplied from one gas nozzle [Figure 4] Figure showing the film formation results when Si2H6 is supplied from three gas nozzles [Figure 5] Figure showing the experimental results of adjusting the film thickness distribution by changing the flow rate distribution. [Figure 6] Figure showing the simulation results of adjusting the film thickness distribution by changing the flow rate distribution. [Figure 7] Figure showing the simulation results of adjusting the film thickness distribution by changing the flow rate distribution. [Figure 8] Figure showing the simulation results of adjusting the film thickness distribution by changing the flow rate distribution. [Figure 9] Figure showing the simulation results of adjusting the film thickness distribution by changing the flow rate distribution. [Figure 10] FIG. 10 is a schematic diagram showing another example of the arrangement of gas nozzles. [Figure 11] FIG. 10 is a schematic diagram showing yet another example of the arrangement of gas nozzles. DETAILED DESCRIPTION OF THE INVENTION

[0008] Hereinafter, non-limiting exemplary embodiments of the present disclosure will be described with reference to the accompanying drawings. In all the accompanying drawings, the same or corresponding reference numerals are used to designate the same or corresponding members or components, and redundant descriptions will be omitted.

[0009] [Processing device] An example of a processing apparatus according to an embodiment will be described with reference to Figures 1 and 2. Figure 1 is a schematic diagram showing an example of a processing apparatus according to an embodiment. Figure 2 is a diagram showing an example of an arrangement of gas nozzles.

[0010] The processing apparatus 1 includes a processing vessel 10, a gas supply unit 30, an exhaust unit 50, a heating unit 70, and a control unit 90.

[0011] The processing vessel 10 includes an inner tube 11 and an outer tube 12. The inner tube 11, also referred to as an inner tube, is formed in a generally cylindrical shape with a ceiling and an open lower end. The inner tube 11 has a ceiling portion 11a that is formed, for example, flat. The outer tube 12, also referred to as an outer tube, is formed in a generally cylindrical shape with a ceiling and an open lower end 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.

[0012] A storage section 13 for storing a gas nozzle is formed along the longitudinal direction (vertical direction) of the inner pipe 11 on one side thereof. The storage section 13 is formed by forming a convex portion 14 by protruding a part of the side wall of the inner pipe 11 outward, and the inside of the convex portion 14 is formed as the storage section 13.

[0013] A rectangular exhaust slit 15 is formed along the longitudinal direction (vertical direction) of the side wall of the inner tube 11 opposite to the storage section 13. The exhaust slit 15 exhausts gas from the inner tube 11. The length of the exhaust slit 15 is the same as the length of a boat 16 described below, or is formed so as to extend in the vertical direction longer than the length of the boat 16.

[0014] The processing vessel 10 accommodates a boat 16. The boat 16 holds a plurality of substrates substantially horizontally with vertical spacing between them. The substrates may be, for example, semiconductor wafers (hereinafter referred to as "wafers W").

[0015] The lower end of the processing vessel 10 is supported by a substantially cylindrical manifold 17 made 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 placed on the flange 18 to support it. A seal member 19 such as an O-ring is interposed between the flange 18 and the lower end of the outer tube 12 to keep the inside of the outer tube 12 airtight.

[0016] A ring-shaped support member 20 is provided on the inner wall of the upper portion of the manifold 17. The support member 20 supports the lower end of the inner tube 11. A lid 21 is airtightly attached to the opening at the lower end of the manifold 17 via a sealing member 22 such as an O-ring. The lid 21 airtightly closes the opening at the lower end of the processing vessel 10, i.e., the opening of the manifold 17. The lid 21 is made of, for example, stainless steel.

[0017] A rotating shaft 24 that rotatably supports the boat 16 via a magnetic fluid seal 23 is provided through the center of the lid 21. The lower part of the rotating shaft 24 is rotatably supported by an arm 25a of an elevating mechanism 25 that is a boat elevator.

[0018] A rotating plate 26 is provided at the upper end of the rotating shaft 24. The boat 16 holding the wafers W is placed on the rotating plate 26 via a quartz heat retention stand 27. Therefore, by raising and lowering the lifting mechanism 25, the lid 21 and the boat 16 move up and down as a unit, allowing the boat 16 to be inserted into and removed from the processing vessel 10.

[0019] The gas supply unit 30 is provided in the manifold 17. The gas supply unit 30 has a plurality of (for example, seven) gas nozzles 31-37.

[0020] The multiple gas nozzles 31-37 are arranged in a row along the circumferential direction inside the housing portion 13 of the inner tube 11. Each gas nozzle 31-37 is provided inside the inner tube 11 along its longitudinal direction, and its base end is bent into an L shape and supported so as to pass through the manifold 17. Each gas nozzle 31-37 has multiple gas holes 31a-37a formed at predetermined intervals along its longitudinal direction. The multiple gas holes 31a-37a are oriented, for example, toward the center C of the inner tube 11 (the wafer W side).

[0021] The gas nozzles 31, 34, and 37 discharge the source gas introduced from a source gas supply source (not shown) through a gas supply pipe (not shown) from multiple gas holes 31a, 34a, and 37a toward the wafer W in a substantially horizontal direction. That is, the gas nozzles 31, 34, and 37 discharge the same source gas into the inner pipe 11. A flow rate controller (not shown), such as a mass flow controller, is connected to the gas supply pipe between the source gas supply source and the gas nozzles 31, 34, and 37. The flow rate controller changes the flow rate of the source gas discharged from the gas nozzles 31, 34, and 37. The source gas may be, for example, a gas containing silicon (Si) or a metal. The multiple gas nozzles 31, 34, and 37 have, for example, the same inner diameter. The multiple gas holes 31a, 34a, and 37a are each provided in the same height range as the boat 16 or in a vertically wider range than the boat 16. As a result, the gas nozzles 31, 34, and 37 inject the source gas into the same height range within the inner pipe 11. In other words, the same source gas is supplied to one wafer W from the multiple gas nozzles 31, 34, and 37. The gas nozzles 31, 34, and 37 are arranged symmetrically with respect to a line L connecting the center C of the inner pipe 11 and the center of the exhaust slit 15. In this embodiment, the gas nozzle 34 is arranged on the line L, and the gas nozzles 31 and 37 are arranged symmetrically with respect to the line L. The gas nozzles 31, 34, and 37 may be further connected to a purge gas supply source (not shown) and configured to inject purge gas into the inner pipe 11.

[0022] The gas nozzles 32, 33, 35, and 36 eject various gases other than the source gas from multiple gas holes 32a, 33a, 35a, and 36a toward the wafer W in a substantially horizontal direction. The flow rates of the various gases ejected from the gas nozzles 32, 33, 35, and 36 are controlled by a flow rate controller (not shown), such as a mass flow controller. The various gases include, for example, a reactive gas, an etching gas, and a purge gas. The reactive gas is a gas that reacts with the source gas to generate a reaction product and may be, for example, a gas containing oxygen or nitrogen. The etching gas is a gas for etching various films and may be, for example, a gas containing a halogen, such as fluorine, chlorine, or bromine. The purge gas is a gas that purges the source gas and the reactive gas remaining in the processing chamber 10 and may be, for example, an inert gas.

[0023] The exhaust unit 50 exhausts gas that is discharged from the inner tube 11 through the exhaust slit 15 and then from the gas outlet 28 through the space P1 between the inner tube 11 and the outer tube 12. The gas outlet 28 is formed on the side wall of the upper part of the manifold 17, above the support part 20. An exhaust passage 51 is connected to the gas outlet 28. A pressure adjustment valve 52 and a vacuum pump 53 are sequentially disposed in the exhaust passage 51, so that the inside of the processing vessel 10 can be exhausted.

[0024] The heating unit 70 is provided around the outer tube 12. The heating unit 70 is provided, for example, on a base plate (not shown). The heating unit 70 has a substantially cylindrical shape so as to cover the outer tube 12. The heating unit 70 includes, for example, a heating element and heats the wafer W in the processing vessel 10.

[0025] The control unit 90 controls the operation of each unit of the processing device 1. The control unit 90 may be, for example, a computer. A computer program that controls the operation of each unit of the processing device 1 is stored in a storage medium. The storage medium may be, for example, a flexible disk, a compact disk, a hard disk, a flash memory, a DVD, or the like.

[0026] [Processing method] As an example of the processing method of the embodiment, a method of forming a silicon oxide film on a wafer W by atomic layer deposition (ALD) using the processing apparatus 1 shown in FIGS. 1 and 2 will be described.

[0027] First, the control unit 90 controls the lifting mechanism 25 to load the boat 16 holding the plurality of wafers W into the processing vessel 10, and then the lid 21 airtightly closes and seals the opening at the bottom of the processing vessel 10.

[0028] Next, the control unit 90 repeats a cycle including a step S1 of supplying a raw material gas, a step S2 of purging, a step S3 of supplying a reactive gas, and a step S4 of purging a raw material gas a predetermined number of times, thereby forming a silicon oxide film having a desired film thickness on the plurality of wafers W.

[0029] In step S1, a silicon-containing gas serving as a source gas is discharged from gas nozzles 31, 34, and 37 into processing chamber 10, whereby the silicon-containing gas is adsorbed onto the wafers W.

[0030] In step S2, a cycle purge is performed in which gas replacement and evacuation are repeated to discharge the silicon-containing gas remaining in the processing vessel 10. The gas replacement is an operation in which a purge gas is supplied into the processing vessel 10 from at least one of the seven gas nozzles 31 to 37. The evacuation is an operation in which the inside of the processing vessel 10 is evacuated by the vacuum pump 53.

[0031] In step S3, an oxidizing gas, which is a reactive gas, is discharged into the processing chamber 10 from at least one of the gas nozzles 32, 33, 35, and 36, so that the silicon source gas adsorbed on the wafers W is oxidized by the oxidizing gas.

[0032] In step S4, cyclic purging, which repeats gas replacement and evacuation, is performed to discharge the oxidizing gas and the like remaining in the processing vessel 10. Step S4 may be the same as step S2.

[0033] After the ALD cycle including steps S1 to S4 is repeated a predetermined number of times, the control unit 90 controls the lifting mechanism 25 to unload the boat 16 from the processing vessel .

[0034] As another example of the processing method of the embodiment, a method of forming a silicon film on a wafer W by chemical vapor deposition (CVD) using the processing apparatus 1 shown in FIGS. 1 and 2 will be described.

[0035] First, the control unit 90 controls the lifting mechanism 25 to load the boat 16 holding the plurality of wafers W into the processing vessel 10, and then the lid 21 airtightly closes and seals the opening at the bottom of the processing vessel 10.

[0036] Subsequently, the control unit 90 discharges a silicon-containing gas, which is a source gas, from the gas nozzles 31, 34, and 37 into the processing chamber 10, thereby depositing a silicon film on the wafer W with a desired thickness.

[0037] Subsequently, the control unit 90 controls the lifting mechanism 25 to unload the boat 16 from the processing vessel 10 .

[0038] According to the embodiment described above, the three gas nozzles 31, 34, and 37 that discharge the same source gas into the inner tube 11 are arranged symmetrically with respect to the line L that connects the center C of the inner tube 11 and the center of the exhaust slit 15. Each of the gas nozzles 31, 34, and 37 is configured to be able to change the flow rate of the source gas discharged from it. This makes it possible to control the concentration distribution of reactive species generated by thermal decomposition of the source gas on the wafer W by changing the flow rate distribution of the source gas discharged from the three gas nozzles 31, 34, and 37. As a result, it is possible to adjust the film thickness distribution of the silicon oxide film formed on the wafer W.

[0039] In particular, by setting the flow rates of the source gases discharged from a pair of gas nozzles 31, 37 arranged symmetrically with respect to a line L to the same flow rate, and changing the flow rate distribution of the source gases discharged from each gas nozzle 31, 34, 37, the adjustment range of the film thickness distribution can be expanded.

[0040] [Example] Example 1 In Example 1, a silicon film was formed on a wafer W by a CVD method using the processing apparatus 1 shown in FIGS. 1 and 2. In Example 1, SiH was supplied from one gas nozzle 34 or three gas nozzles 31, 34, and 37. The flow rate of SiH supplied from one gas nozzle 34 and the total flow rate of SiH supplied from the three gas nozzles 31, 34, and 37 were set to the same flow rate. More specifically, the flow rate of SiH supplied from one gas nozzle 34 was set to 350 sccm, and the flow rates of SiH supplied from the three gas nozzles 31, 34, and 37 were each set to 117 sccm. Other conditions were set to be the same for the conditions when SiH was supplied from one gas nozzle 34 and the conditions when SiH was supplied from the three gas nozzles 31, 34, and 37.

[0041] FIG. 3 shows the results of film formation when Si2H6 is supplied from a single gas nozzle 34. In FIG. 3, the wafer map, film thickness, and in-plane uniformity of silicon films formed on wafers W arranged in the TOP region, CTR region, and BTM region, respectively, are shown from left to right. The upper part of FIG. 3 shows the results when the film formation process was performed with the wafer W stopped rotating, while the lower part of FIG. 3 shows the results when the wafer W was rotated around the vertical axis. The TOP region, CTR region, and BTM region refer to the top, center, and bottom of the boat 16, respectively, in the height direction. The wafer map shows the in-plane distribution of the film thickness of the silicon film formed on the wafer W, with the 6 o'clock direction indicating the direction in which the gas nozzle 34 is positioned and the 12 o'clock direction indicating the direction in which the exhaust slit 15 is positioned.

[0042] As shown in the upper part of FIG. 3, when Si2H6 is supplied from a single gas nozzle 34, the thickness of the silicon film is thinnest at the 6 o'clock position and increases fan-shaped, reaching its thickest at the 12 o'clock position, when the rotation of the wafer W is stopped. This is because the deposition of the silicon film is due to the concentration of reactive species generated by thermal decomposition of the source gas. It is believed that the film thickness increases as the source gas discharged from the gas nozzle 34 is gradually heated and thermally decomposed. Note that when a large amount of gas is consumed above the wafer W or when the source gas is excited into plasma at the gas nozzle 34, the film thickness on the gas nozzle 34 side may be thickest, and the film thickness on the exhaust slit 15 side may become thinner due to gas consumption or deactivation. In either case, the film thickness increases or decreases from the position of the gas nozzle 34 that supplies the source gas.

[0043] As shown in the lower part of FIG. 3, when the wafer W is rotated, the film thickness distribution is such that the film thickness is thicker at the wafer edge than at the wafer center.

[0044] FIG. 4 shows the results of film formation when Si2H6 is supplied from three gas nozzles 31, 34, and 37. In FIG. 4, the wafer map, film thickness, and in-plane uniformity of silicon films formed on wafers W arranged in the TOP region, CTR region, and BTM region, respectively, are shown from left to right. The upper part of FIG. 4 shows the results when the film formation process was performed with the wafer W stopped rotating, while the lower part of FIG. 4 shows the results when the wafer W was rotated around the vertical axis. The TOP region, CTR region, and BTM region refer to the top, center, and bottom of the boat 16, respectively, in the height direction. The wafer map shows the in-plane distribution of the film thickness of the silicon film formed on the wafer W, with the 6 o'clock direction indicating the direction in which the gas nozzle 34 is positioned and the 12 o'clock direction indicating the direction in which the exhaust slit 15 is positioned.

[0045] As shown in the upper part of Figure 4, when Si2H6 is supplied from the three gas nozzles 31, 34, and 37, the thickness of the silicon film is thin in the range from the 4 o'clock direction to the 8 o'clock direction when the rotation of the wafer W is stopped. Thus, in the example shown in the upper part of Figure 4, the region with thin film thickness is larger at the edge of the wafer than in the example shown in the upper part of Figure 3. As a result, as shown in the lower part of Figure 4, when the wafer W is rotated, the film thickness distribution is such that the film thickness is thinner at the edge of the wafer than at the center.

[0046] Example 2 In Example 2, a silicon film was formed on a wafer W by a CVD method using the processing apparatus 1 shown in Figures 1 and 2. In Example 2, the total flow rate of Si2H6 supplied from the three gas nozzles 31, 34, and 37 was fixed at 600 sccm, and the flow rate distribution of Si2H6 supplied from each of the gas nozzles 31, 34, and 37 was changed. The flow rate distribution of Si2H6 was set to four levels: gas nozzle 31 / gas nozzle 34 / gas nozzle 37 = 200 / 200 / 200 sccm, 150 / 300 / 150 sccm, 100 / 400 / 100 sccm, and 0 / 600 / 0 sccm.

[0047] FIG. 5 shows the experimental results of adjusting the film thickness distribution by changing the flow rate distribution. In FIGS. 5(a) to 5(d), the horizontal axis represents the wafer position [mm], and the vertical axis represents the silicon film thickness. Regarding the wafer position, 0 mm is the center of the wafer W, and ±150 mm is the outer edge of the wafer W. FIG. 5(a) shows the results when the gas nozzle 31 / gas nozzle 34 / gas nozzle 37 = 200 / 200 / 200 sccm. FIG. 5(b) shows the results when the gas nozzle 31 / gas nozzle 34 / gas nozzle 37 = 150 / 300 / 150 sccm. FIG. 5(c) shows the results when the gas nozzle 31 / gas nozzle 34 / gas nozzle 37 = 100 / 400 / 100 sccm. FIG. 5(d) shows the results when the gas nozzle 31 / gas nozzle 34 / gas nozzle 37 = 0 / 600 / 0 sccm.

[0048] 5(a) to 5(d), the film thickness distribution tended to change stepwise from a convex to a concave distribution as the flow rate of Si2H6 supplied from gas nozzle 34 was increased and the flow rates of Si2H6 supplied from gas nozzles 31 and 37 were decreased. This result showed that a desired film thickness distribution could be obtained by changing the flow rate distribution of Si2H6 supplied from gas nozzles 31, 34, and 37.

[0049] Furthermore, as shown in Figures 5(a) to 5(d), discharging Si2H6 from three gas nozzles 31, 34, and 37 tended to achieve higher in-plane uniformity than discharging Si2H6 from a single gas nozzle 34. More specifically, as shown in Figure 5(a), when the gas nozzle 31 / gas nozzle 34 / gas nozzle 37 flow rates were 200 / 200 / 200 sccm, the in-plane film thickness uniformity (Win Unif) was ±2.1%. As shown in Figure 5(b), when the gas nozzle 31 / gas nozzle 34 / gas nozzle 37 flow rates were 150 / 300 / 150 sccm, the in-plane film thickness uniformity was ±1.3%. As shown in Figure 5(c), when the gas nozzle 31 / gas nozzle 34 / gas nozzle 37 flow rates were 100 / 400 / 100 sccm, the in-plane film thickness uniformity was ±1.1%. As shown in FIG. 5(d), when gas nozzle 31 / gas nozzle 34 / gas nozzle 37=0 / 600 / 0 sccm, the in-plane uniformity of the film thickness was ±4.6%.

[0050] [Simulation results] First, a simulation was performed using thermal fluid analysis to examine the concentration distribution of reactive species in the processing vessel 10 when the flow rate distribution of the source gas discharged from the gas nozzles 31, 34, and 37 was changed in the processing apparatus 1 shown in Figures 1 and 2. In this simulation, the flow rate of the source gas discharged from the gas nozzle 31 and the flow rate of the source gas discharged from the gas nozzle 37 were always set to the same flow rate. The reason for analyzing the concentration distribution of reactive species is that the thickness of a predetermined film formed on the wafer W is determined by the concentration of reactive species generated by thermal decomposition of the source gas. The conditions for this simulation are as follows:

[0051] <Simulation conditions> Source gas: Si2H6 Flow distribution: 7 levels from X1 to X7 X1:0 / 600 / 0sccm X2: 50 / 500 / 50sccm X3: 100 / 400 / 100sccm X4: 150 / 300 / 150sccm X5: 200 / 200 / 200sccm X6: 250 / 100 / 250sccm X7: 300 / 0 / 300sccm

[0052] 6 and 7 are diagrams showing the results of a simulation in which the film thickness distribution was adjusted by changing the flow rate distribution. In FIG. 6, the gas concentration at the wafer center [kmol / m 3 ] indicates the concentration of reactive species at the center of the wafer, and the wafer edge average gas concentration [kmol / m 3 ] indicates the average concentration of reactive species on a circle with a diameter of 297 mm centered at the center of the wafer. The average gas concentration at the wafer edge was also calculated when the gas concentration at the wafer center was set to 1. In Figure 7, the horizontal axis indicates the flow rate distribution levels X1 to X7, and the vertical axis indicates the average gas concentration at the wafer edge when the gas concentration at the wafer center was set to 1.

[0053] The simulation results shown in FIGS. 6 and 7 reveal the following. The average concentration of reactive species at the edge relative to the center of the wafer is highest when the source gas is discharged from one gas nozzle 34 (level X1). With the total flow rate of the source gas discharged from the gas nozzles 31, 34, and 37 fixed, the average concentration of reactive species at the edge relative to the center of the wafer decreases as the flow rate of the source gas discharged from the gas nozzles 31 and 37 increases (levels X1 to X5). When the flow rates of the three gas nozzles 31, 34, and 37 are uniform, the average concentration of reactive species at the edge relative to the center of the wafer is lowest (level X5). The simulation results shown in FIGS. 6 and 7 are substantially consistent with the film thickness distribution results obtained in Example 2 described above.

[0054] Next, a simulation was performed using thermal fluid analysis to examine the concentration distribution of reactive species in the processing vessel 10 when the flow rate distribution of the source gas discharged from the gas nozzles 31, 34, and 37 was changed in the processing apparatus 1 shown in Figures 1 and 2. In this simulation, the flow rate of the source gas discharged from the gas nozzle 34 was fixed at 200 sccm, and the flow rate distribution of the source gas discharged from the gas nozzle 31 and the source gas discharged from the gas nozzle 37 was changed. The reason for analyzing the concentration distribution of reactive species is that the thickness of a predetermined film formed on the wafer W is determined by the concentration of reactive species generated by thermal decomposition of the source gas. The conditions for this simulation are as follows:

[0055] <Simulation conditions> Source gas: Si2H6 Flow distribution: 5 levels Y1 to Y5 Y1: 200 / 200 / 200sccm Y2: 250 / 200 / 150sccm Y3: 300 / 200 / 100sccm Y4: 350 / 200 / 50sccm Y5: 400 / 200 / 0sccm

[0056] Level Y1 is a symmetrical gas flow pattern in which the source gas is discharged at equal flow rates from the two gas nozzles 31 and 37. Level Y5 is a case in which no source gas is discharged from the gas nozzle 37, and is the condition in which the bias in the gas flow rate inside the processing vessel 10 is greatest.

[0057] 8 and 9 are diagrams showing the simulation results in which the film thickness distribution was adjusted by changing the flow rate distribution. In FIG. 8, the gas concentration at the wafer center [kmol / m 3 ] indicates the concentration of reactive species at the center of the wafer, and the wafer edge average gas concentration [kmol / m 3 ] indicates the average concentration of reactive species on a circle with a diameter of 297 mm centered at the center of the wafer. The average gas concentration at the wafer edge was also calculated when the gas concentration at the wafer center was set to 1. In Figure 9, the horizontal axis indicates the flow rate distribution levels Y1 to Y5, and the vertical axis indicates the average gas concentration at the wafer edge when the gas concentration at the wafer center was set to 1.

[0058] 8 and 9 reveal the following: The average concentration of reactive species at the edge of the wafer relative to the center is lowest when the same flow rate of gas is discharged from the gas nozzles 31 and 37, that is, when the gas flows are uniformly and symmetrically (levels Y1 to Y5). As the difference in flow rate between the source gas discharged from the gas nozzle 31 and the source gas discharged from the gas nozzle 37 increases, the average concentration of reactive species at the edge of the wafer relative to the center increases.

[0059] 6 to 9, it can be said that the average concentration of reactive species at the wafer edge relative to the center can be adjusted over the widest range (0.935 to 0.987) when the gas is uniformly and symmetrically flowed. In other words, it can be said that the adjustment range of the in-plane film thickness distribution can be expanded by ejecting the source gas from multiple gas nozzles so that the flow rate distribution of the source gas is symmetrical with respect to the line L. To achieve this, it is preferable to arrange multiple gas nozzles symmetrically with respect to the line L connecting the center C of the inner tube 11 and the center of the exhaust slit 15.

[0060] In the above embodiment, the source gas is an example of a process gas.

[0061] The embodiments disclosed herein should be considered to be illustrative in all respects and not restrictive, and the above-described embodiments may be omitted, substituted, or modified in various ways without departing from the scope and spirit of the appended claims.

[0062] In the above embodiment, an example has been described in which there are three gas nozzles that supply the same source gas, but the present disclosure is not limited to this. For example, there may be four or more gas nozzles that supply the same source gas.

[0063] FIG. 10 is a schematic diagram showing another example of the arrangement of gas nozzles. In FIG. 10, gas nozzles other than those that discharge source gases are not shown. As shown in FIG. 10, the gas supply unit 130 includes four gas nozzles 131 to 134. Each of the four gas nozzles 131 to 134 discharges the same source gas into the processing chamber 10. Each of the gas nozzles 131 to 134 has multiple gas holes 131 a to 134 a spaced apart along its longitudinal direction. The multiple gas holes 131 a to 134 a are oriented toward the center C of the inner tube 11 (the wafer W side), for example. The four gas nozzles 131 to 134 are arranged symmetrically with respect to a line L that connects the center C of the inner tube 11 and the center of the exhaust slit 15. More specifically, the gas nozzles 131 and 134 are arranged symmetrically with respect to the line L, and the gas nozzles 132 and 133 are arranged symmetrically with respect to the line L.

[0064] FIG. 11 is a schematic diagram showing yet another example of the arrangement of gas nozzles. In FIG. 11, gas nozzles other than those that discharge the source gas are not shown. As shown in FIG. 11, the gas supply unit 230 includes four gas nozzles 231-234. Each of the four gas nozzles 231-234 discharges the same source gas into the processing chamber 10. Each of the gas nozzles 231-234 has a plurality of gas holes 231a-234a spaced at predetermined intervals along its longitudinal direction. The gas holes 231a-234a are oriented toward the center C of the inner tube 11 (the wafer W side), for example. Three of the four gas nozzles 231-234, namely, the gas nozzles 231-233, are symmetrically arranged with respect to a line L that connects the center C of the inner tube 11 and the center of the exhaust slit 15. More specifically, the gas nozzle 232 is arranged on the line L, and the gas nozzles 231 and 233 are symmetrically arranged with respect to the line L. The remaining gas nozzle 234 of the four gas nozzles 231 to 234 is arranged adjacent to gas nozzle 233 in the circumferential direction inside the container 13. The multiple gas nozzles supplying the same source gas in this manner need only include at least three gas nozzles arranged symmetrically with respect to the line L, and may also include gas nozzles other than the three symmetrically arranged gas nozzles.

[0065] In the above embodiment, the processing gas is a source gas, but the present disclosure is not limited to this. For example, the processing gas may be a reactive gas.

[0066] In the above embodiment, the gas nozzle is an L-shaped pipe, but the present disclosure is not limited to this. For example, the gas nozzle may be a straight pipe that extends along the longitudinal direction of the inner pipe inside the side wall of the inner pipe and has its lower end inserted into and supported by a nozzle support portion (not shown).

[0067] In the above embodiment, the processing apparatus is described as an apparatus that supplies gas from gas nozzles arranged along the longitudinal direction of the processing vessel and exhausts the gas from exhaust slits arranged opposite the gas nozzles, but the present disclosure is not limited to this. For example, the processing apparatus may be an apparatus that supplies gas from gas nozzles arranged along the longitudinal direction of the wafer boat and exhausts the gas from gas outlets arranged above or below the wafer boat.

[0068] In the above embodiment, the processing vessel is a vessel having a double-pipe structure including an inner pipe and an outer pipe, but the present disclosure is not limited thereto. For example, the processing vessel may be a vessel having a single-pipe structure.

[0069] In the above embodiment, the processing apparatus is a non-plasma apparatus, but the present disclosure is not limited to this. For example, the processing apparatus may be a plasma apparatus such as a capacitively coupled plasma apparatus or an inductively coupled plasma apparatus. [Explanation of symbols]

[0070] 1 Processing equipment 10 Processing container 15 Exhaust slit 31, 34, 37 Gas nozzle W wafer

Claims

1. a processing vessel having a substantially cylindrical shape and an exhaust slit formed in a sidewall, the processing vessel accommodating a substrate therein; a plurality of gas nozzles extending in a vertical direction along the inside of the sidewall of the processing vessel and arranged symmetrically with respect to a line connecting a center of the processing vessel and a center of the exhaust slit, each gas nozzle supplying the same processing gas into the processing vessel; a flow rate controller for adjusting the flow rate of the processing gas supplied from the plurality of gas nozzles; a control unit that controls the flow rate controller; Equipped with the process gas is a silicon-containing gas; the control unit controls to form a silicon oxide film on the substrate by atomic layer deposition; the control unit controls, when depositing the silicon oxide film, to adjust a film thickness distribution of the silicon oxide film deposited on the substrate by changing a flow rate distribution of the process gas supplied from the plurality of gas nozzles while keeping a total flow rate of the process gas supplied from the plurality of gas nozzles fixed. Processing equipment.

2. the plurality of gas nozzles include a first gas nozzle and a second gas nozzle that are arranged symmetrically with respect to the straight line, the control unit controls the flow rate distribution of the processing gas supplied from the plurality of gas nozzles to be changed while setting the flow rates of the processing gas supplied from the first gas nozzle and the second gas nozzle to the same flow rate. The processing device of claim 1 .

3. the plurality of gas nozzles includes a third gas nozzle arranged on the straight line. The processing device of claim 2 .

4. the plurality of gas nozzles include a fourth gas nozzle and a fifth gas nozzle arranged symmetrically with respect to the straight line; The processing device of claim 2 .

5. the plurality of gas nozzles includes a third gas nozzle arranged on the straight line, the control unit controls the flow rate distribution of the processing gas supplied from the plurality of gas nozzles to be changed while keeping the flow rate of the processing gas supplied from the third gas nozzle fixed. The processing device of claim 1 .

6. a step of loading a substrate into a processing chamber having a substantially cylindrical shape and an exhaust slit formed in a side wall; supplying the same processing gas into the processing vessel from each of a plurality of gas nozzles extending vertically along the inner side of the sidewall of the processing vessel and arranged symmetrically with respect to a line connecting the center of the processing vessel and the center of the exhaust slit; and the process gas is a silicon-containing gas; the step of supplying the process gas includes forming a silicon oxide film on the substrate by atomic layer deposition; the supplying of the process gas includes, when depositing the silicon oxide film, adjusting a film thickness distribution of the silicon oxide film deposited on the substrate by changing a flow rate distribution of the process gas supplied from the plurality of gas nozzles while keeping a total flow rate of the process gas supplied from the plurality of gas nozzles fixed. Processing method.

7. the plurality of gas nozzles include a first gas nozzle and a second gas nozzle that are arranged symmetrically with respect to the straight line, the supplying of the process gas includes changing a flow rate distribution of the process gas supplied from the plurality of gas nozzles while setting the flow rates of the process gas supplied from the first gas nozzle and the second gas nozzle to the same flow rate. The processing method according to claim 6.

8. the plurality of gas nozzles includes a third gas nozzle arranged on the straight line, the supplying of the processing gas includes changing a flow rate distribution of the processing gas supplied from the plurality of gas nozzles while keeping a flow rate of the processing gas supplied from the third gas nozzle fixed. The processing method according to claim 6.

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