Substrate treatment device and substrate treatment method

Abstract

This substrate treatment device comprises: a mounting table for a substrate and an upper structural body in a treatment container; and an exhaust port that opens to the outside of the mounting table in a bottom wall of the treatment container in a plan view and allows removal therethrough of gas inside the treatment container. The upper structural body is provided with a body part that faces the mounting table, and a first annular part that extends downward from the body part to regulate the flow of a treatment gas. The substrate treatment device further comprises a drive mechanism that changes the distance between the mounting table and the upper structural body, a first gas supply mechanism that supplies the treatment gas into the treatment container, a second annular part that extends upward from the bottom wall of the treatment container and surrounds the first annular part, and a second gas supply mechanism that supplies an inert gas into a first gap which is formed between the upper structural body and the second annular part in a manner being contiguous with the exhaust port.

Description

Substrate processing apparatus and substrate processing method

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

[0002] In a semiconductor manufacturing apparatus, a process is performed in which a substrate is placed on a stage in a processing chamber, gas is supplied from a gas supply unit arranged opposite the stage, the processing chamber is depressurized, and a film is formed on the substrate, and the gas in the processing chamber is exhausted through an exhaust path. In performing this film formation process on a substrate, Patent Document 1 proposes a technology in which a conductance adjustment plate is provided to adjust the exhaust conductance toward the outer periphery of the substrate, thereby uniforming the pressure in the processing space during film formation.

[0003] JP 2015-183211 A

[0004] The present disclosure provides a technology that can prevent diffusion of processing gas into a processing vessel in a substrate processing apparatus in which the distance between a mounting table on which a substrate is placed and an upper structure placed above the mounting table is changed within the processing vessel.

[0005] the exhaust port opening in a bottom wall of the processing vessel to the outside of the mounting table in a plan view and exhausting the inside of the processing vessel; a first gas supply mechanism supplying a processing gas for processing the substrate placed on the mounting table into the processing vessel; an upper structure including a main body provided above the mounting table to face the mounting table and a first annular portion extending downward from the main body to regulate the flow of the processing gas, the first annular portion having a lower end located closer to an edge of the bottom wall than the exhaust port in a plan view; a drive mechanism for changing the distance between the mounting table and the upper structure; a second annular portion extending upward from the bottom wall of the processing vessel to surround the first annular portion; and a second gas supply mechanism supplying an inert gas to a first gap formed by the upper structure and the second annular portion so as to communicate with the exhaust port.

[0006] According to the present disclosure, in a substrate processing apparatus in which the distance between a mounting table on which a substrate is placed and an upper structure arranged above the mounting table is changed within a processing vessel, it is possible to prevent diffusion of processing gas into the processing vessel.

[0007] FIG. 1 is a longitudinal sectional view showing a first embodiment of the substrate processing apparatus. FIG. 2 is a longitudinal sectional view showing the first embodiment of the substrate processing apparatus. FIG. 3 is a plan view showing a configuration example of a processing vessel. FIG. 4 is a longitudinal sectional view showing a part of the first embodiment of the substrate processing apparatus. FIG. 5 is a perspective view showing a part of a configuration example of an annular groove. FIG. 6 is a longitudinal sectional view showing a part of the first embodiment of the substrate processing apparatus. FIG. 7 is a longitudinal sectional view showing a part of a modified example of the first embodiment of the substrate processing apparatus. FIG. 8 is a longitudinal sectional view showing a second embodiment of the substrate processing apparatus. FIG. 9 is a longitudinal sectional view showing a part of the second embodiment of the substrate processing apparatus. FIG. 10 is a longitudinal sectional view showing a part of a modified example of the second embodiment of the substrate processing apparatus. FIG. 11 is a longitudinal sectional view showing a third embodiment of the substrate processing apparatus.

[0008] First Embodiment of Substrate Processing Apparatus A configuration example of a substrate processing apparatus according to the present disclosure will be described with reference to FIGS. 1 and 2 , taking as an example a case where the apparatus is applied to an apparatus that performs a film formation process by atomic layer deposition (ALD) on a substrate, i.e., a semiconductor wafer (hereinafter referred to as a "wafer") W. As shown in these figures, the substrate processing apparatus 1 includes a processing vessel 11 that stores and processes a wafer W. The processing vessel 11 is configured, for example, in a circular shape in a plan view, and includes an upper wall 111, a side wall 12, and a bottom wall 13, each of which is made of, for example, the same metal material. In addition, an upper structure 2 is provided below the upper wall 111 of the processing vessel 11, spaced apart from the upper wall 111.

[0009] The upper structure 2 is configured, for example, in a circular shape in a plan view, and its periphery is surrounded by the side wall 12 of the processing vessel 11. In this example, the upper structure 2 is configured to be able to freely rise and fall, and its upper surface is formed as a flat surface, so that when the upper structure 2 is in a transfer position (the position shown in FIG. 2 ) described below, the upper structure 2 is positioned above a transfer port 18. In addition, the side wall 12 is formed perpendicular to the bottom wall 13, and is configured to extend vertically upward from the outer edge of the bottom wall 14, and in this example, forms a second annular portion.

[0010] A mounting table 3 on which a wafer W is placed is provided on the bottom wall 13 of the processing vessel 11. The mounting table 3 has, for example, a flat cylindrical shape and is made of, for example, ceramics so as to be able to withstand high temperatures, and has a built-in heater 31. A support portion 32 extending downward is provided at the center of the underside of the mounting table 3 to support the mounting table 3 on the bottom wall 13. Furthermore, the center of the bottom wall 13 of the processing vessel 11 protrudes downward. A recess 131 is formed in this protruding portion to match the shape of the support portion 32, and the support portion 32 is provided within the recess 131.

[0011] Furthermore, exhaust ports 14 for exhausting the inside of the processing vessel 11 are formed in the bottom wall 13 of the processing vessel 11 so as to open vertically upward outside the mounting table 3 in a plan view. In this example, a plurality of exhaust ports 14, for example, eight exhaust ports 14, are formed along the circumferential direction of the mounting table 3, as shown in Fig. 3, and these exhaust ports 14 are arranged at equal intervals around the periphery of the mounting table 3. Each exhaust port 14 is connected to a common exhaust mechanism 16 via an exhaust path 15 extending downward, and this exhaust mechanism 16 includes a vacuum pump, a valve for opening and closing the exhaust path 15, and the like.

[0012] The upper structure 2 is disposed to face the mounting table 3 from above, and is configured to supply a processing gas for processing the wafer W toward the wafer W mounted on the mounting table 3. The upper structure 2 includes a main body 21 provided above the mounting table 3 to face the mounting table 3, and a first annular portion 22 extending downward from the main body 21 outside the mounting table 3.

[0013] The main body 21 in this example has a circular recess 23 on its underside. The bottom surface of the recess 23 (which is the ceiling surface of the processing vessel 11 because the recess 23 is formed upside down) is a horizontal flat surface, forming a facing region 231 facing the wafer W on the mounting table 3. On the underside of the main body 21, an outer region (outer region) 232 forming the opening edge of the recess 23 is formed as a wide, horizontal, annular flat surface that is lower in height than the facing region 231. In a plan view, a first annular portion 22 is formed adjacent to the outer periphery of the outer region 232.

[0014] The upper structure 2 also has a process gas outlet (second outlet) 24, for example, at the center of its lower surface, and the second outlet 24 is formed to open in the facing region 231. The upper structure 2 also has a flow path 25 connected to the second outlet 24 and a supply pipe 261 connected to the flow path 25. The base end of the supply pipe 261 penetrates the upper wall 111 of the processing vessel 11 and is connected to a first gas supply mechanism 26. The first gas supply mechanism 26 is a mechanism that supplies the processing gas into the processing vessel 11, and includes a process gas supply source, a valve that opens and closes the supply pipe 261, a gas flow rate adjuster, etc.

[0015] For example, when two types of gases are alternately supplied as process gases to the process chamber 11 to perform film formation processing on the wafer W by ALD, the first gas supply mechanism 26 includes a source gas supply source, a reactive gas supply source, and a replacement gas supply source. In this example, the process gases are the source gas, the reactive gas, and the replacement gas. Note that the upper structure 2 is not limited to this example, and may have a configuration in which a large number of second outlets are formed on its lower surface and the process gas is discharged from these second outlets in a shower-like manner.

[0016] The upper structure 2 is configured so that the distance between it and the mounting table 3 can be changed by the drive mechanism 27. Specifically, the upper structure 2 is configured so that it can be raised and lowered vertically by the drive mechanism 27 between a processing position (see FIG. 1) where the wafer W is processed inside the processing vessel 11 and a transfer position (see FIG. 2) above the processing position for transferring the wafer W into and out of the processing vessel 11. In this example, the state in which the upper structure 2 is in the processing position is a first state in which the distance between the upper structure 2 and the mounting table 3 is a first distance. Meanwhile, the state in which the upper structure 2 is in the transfer position is a second state in which the distance between the upper structure 2 and the mounting table 3 is a second distance, which is set to be longer than the first distance. Since the upper structure 2 is configured so that it can be raised and lowered, the supply pipe 261 in this example rises and falls in accordance with the rise and fall of the upper structure 2. At this time, the upper structure 2 and the supply pipe 261 are configured to rise and fall while maintaining the airtightness of the processing vessel 11.

[0017] Before continuing to describe the detailed structure of the upper structure 2, the reason why the upper structure 2 is raised and lowered in this manner and an overview of the configuration of the substrate processing apparatus 1 will be described. For this description, a comparative example will be taken as a film formation apparatus in which the mounting table 3 is raised and lowered within the processing vessel 11 instead of the upper structure 2. In this comparative example, when the wafer W is transferred to the mounting table 3, the mounting table 3 is located at a relatively lower position (lower position) within the processing vessel 11. When processing the wafer W, the mounting table 3 is located at a processing position above the lower position so that a sufficient amount and concentration of processing gas can be supplied to the wafer W.

[0018] By setting the processing position in this manner, a relatively large space is formed between the bottom wall 13 of the processing vessel 11 and the underside of the mounting table 3 at the processing position in the comparative example. Incidentally, to minimize the impact on the processing of the wafer W, it is necessary to prevent the adhesion of components constituting the processing gas to the side and underside of the mounting table 3. Furthermore, if the processing gas intrudes behind the backside of the mounting table 3, it may diffuse and remain within the processing vessel 11, possibly leaking out of the processing vessel 11 through the transfer port when the wafer W is unloaded. For this reason, an inert gas is supplied to the underside and side of the mounting table 3 as a purge gas to prevent the processing gas from intruding. However, as described above, a large space is formed below the mounting table 3. Therefore, in order to achieve a sufficient purging effect, a relatively large amount of purge gas may be required. Furthermore, such a large supply amount of purge gas may dilute the processing gas, affecting the processing of the wafer W, or may require a large exhaust mechanism 16.

[0019] Therefore, in the substrate processing apparatus 1 of this embodiment, the relative positions of the mounting table 3 and the bottom wall 13 are fixed so that the underside of the mounting table 3 is close to the bottom wall 13 of the processing vessel 11, forming a relatively small gap. This configuration reduces the flow rate of the inert gas supplied to the underside of the mounting table 3. While the relative positions of the mounting table 3 and the bottom wall 13 are fixed, the upper structure 2 is configured to be raised and lowered so that the wafer W can be transported relative to the mounting table 3 and sufficient processing gas can be supplied to the wafer W. The inert gas supplied to the underside of the mounting table 3 flows to the exhaust port 14 through a gap formed around the side surface of the mounting table 3. The gap around the side surface is also formed small, thereby reducing the flow rate of the inert gas used. The gaps on the underside and side surfaces of the mounting table 3 correspond to the second gap 42 described below.

[0020] As described above, by configuring the upper structure 2 to rise and fall, a gap is formed between the outer circumferential surface of the upper structure 2 and the sidewall of the processing vessel 11. To prevent the processing gas from circulating above the upper structure 2 of the processing vessel 11 through the gap, diffusing into the processing vessel 11, and remaining there, resulting in leakage to the outside when the wafer is unloaded, the upper structure 2 is provided with a first annular portion 22 for regulating the flow of the processing gas and guiding it to the exhaust port 14. In addition, an inert gas is supplied to this gap, and the flow of this inert gas toward the exhaust port 14 is also utilized to prevent the processing gas from diffusing into the processing vessel 11. This gap corresponds to a first gap 41, which will be described later, and is formed by the outer circumferential surfaces of the main body portion 21 and the first annular portion 22 that configure the upper structure 2.

[0021] Returning to the description of the configuration of the upper structure 2, when the upper structure 2 is in the processing position (first state), as shown in Fig. 1, a processing space 10 for the wafer W is formed between the recess 23 of the upper structure 2 and the mounting table 3. At this time, the outer region 232 of the upper structure 2 forms a gas flow path 17 as a gap between it and the upper surface of the mounting table 3. When viewed from the wafer W on the mounting table 3, this gas flow path 17 is formed on the side of the wafer W so as to surround the wafer W. The height of the gas flow path 17 when the upper structure 2 is in the processing position, i.e., the distance between the lower surface of the outer region 232 and the upper surface of the mounting table 3, is, for example, 1 mm.

[0022] The outer region 232 of the upper structure 2 is formed from the region facing the mounting table 3 outward to a position facing the exhaust port 14, and as described above, its outer periphery is connected to the first annular portion 22. The first annular portion 22 is formed by the peripheral portion including the side surface of the main body portion 21 extending downward, and in a plan view, the outer periphery of the main body portion 21 and the outer periphery of the first annular portion 22 are aligned.

[0023] The base end side (upper side) of the first annular portion 22 is configured as an inclined portion 233, and the inner peripheral surface of the inclined portion 233 is configured as an inclined surface that slopes downward toward the periphery of the processing vessel 11. Therefore, the thickness of the inclined portion 233 decreases downward. The inclined surface is located above a portion of the exhaust port 14 that is closer to the periphery of the processing vessel 11, and serves to guide the processing gas to the exhaust port 14 and prevent the processing gas from stagnating.

[0024] A supplementary explanation of this prevention of stagnation is provided below. If the inclined portion 233 were not provided and the inner circumferential surface of the base end side of the first annular portion 22 were formed perpendicular to the bottom surface of the main body portion 21, the area formed by these surfaces (i.e., the corner) would have a relatively small angle (=90°). Therefore, there is a risk of process gas stagnation in this area. However, by providing the inclined portion 233, such an area with a relatively small angle is not formed, and process gas stagnation is prevented. Note that, with respect to the aforementioned recess 23, similar to the inclined portion 233, the side surface of the recess 23 is formed as an inclined surface that slopes downward toward the periphery of the processing vessel 11 with respect to the facing area 231, which is the bottom surface of the recess 23, in order to prevent process gas stagnation.

[0025] Returning to the description of the first annular portion 22, as shown in FIGS. 1 to 4 , the lower end of the first annular portion 22 is configured to extend downward from the inclined portion 233 at a position closer to the edge of the bottom wall 13 than the exhaust ports 14. More specifically, the lower end of the first annular portion 22 is a vertically extending cylinder, and the upper end of the inner circumferential surface of this cylinder is connected to the lower end of the inclined surface. The lower end of the first annular portion 22 is configured as a horizontal, annular, flat surface, and in plan view, this lower end is located closer to the edge (closer to the periphery) of the processing vessel 11 than the exhaust ports 14. More specifically, as shown in FIG. 3 , in plan view, the inner periphery of the lower end of the first annular portion 22 is located closer to the periphery of the processing vessel 11 than the exhaust ports 14.

[0026] Furthermore, the lower end of the first annular portion 22 has a flat surface facing the bottom wall 13 of the processing vessel 11, and in the first state in which the upper structure 2 is in the processing position, the lower end is located below the upper surface (the surface on which the wafer W is placed) of the mounting table 3. As a result, as will be described later in the description of processing the wafer W, the processing gas flowing over the mounting table 3 toward the periphery of the processing vessel 11 collides with the first annular portion 22 and is reliably guided to the exhaust port 14.

[0027] In addition, in this first state, the lower end of first annular portion 22 is in close proximity to bottom wall 13 of processing vessel 11, which suppresses the flow of processing gas into first gap 41 and reliably prevents leakage of processing gas from first gap 41 to the outside of processing vessel 11. In this first state, the distance between the lower surface of first annular portion 22 and the upper surface of bottom wall 13 of processing vessel 11 is preferably set to, for example, 1 mm to 2 mm or less.

[0028] As described above, the sidewall 12 of the processing vessel 11 constitutes the second annular portion, and when viewed from the first annular portion 22, the second annular portion is formed to surround the first annular portion 22. When the upper structure 2 is positioned at the processing position, a gap formed between the upper structure 2 and the second annular portion (sidewall 12) is the first gap 41. An inert gas is supplied to this first gap 41, and the first gap 41 communicates with the exhaust port 14 so that the inert gas flows toward the exhaust port 14. Therefore, in the following description, the term "first gap 41" refers to the state in which the upper structure 2 is positioned in the first state, which is the processing position. To prevent diffusion of processing gas into the processing vessel 11 through the first gap 41, the size of the first gap 41 is preferably 1 mm or less in width (the distance between the first annular portion 22 and the sidewall 12).

[0029] As shown in FIGS. 3 to 5 , an annular groove 5 is formed in the sidewall 12 of the processing vessel 11. The annular groove 5 faces the first gap 41 and is formed around the entire circumference of the sidewall 12. In this example, the annular groove 5 is configured by forming a recess 51 on the inner surface of the sidewall 12. In this example, as shown in FIG. 4 , the annular groove 5 has a rectangular cross-sectional shape that opens toward the first gap 41. The annular groove 5 serves as a diffusion space for sufficiently supplying the inert gas around the entire circumference of the first gap 41. To ensure sufficient diffusibility of the inert gas, for example, the depth of the annular groove 5 (the depth of the recess 51) is greater than the width of the first gap 41. Note that the annular groove 5 is omitted in FIGS. 1 and 2 for convenience of illustration.

[0030] A first discharge port 52 that opens into the annular groove 5 and discharges the inert gas is formed in the annular groove 5. For example, a flow path 531 is provided in the side wall 12 of the processing vessel 11 so as to communicate with the annular groove 5. The flow path 531 is formed so as to connect the outer surface and the inner surface of the side wall 12, for example, and its tip opens laterally into the annular groove 5 to form the first discharge port 52.

[0031] The base end of the flow path 531 is connected to a second gas supply mechanism 53 via a supply pipe 532 provided outside the processing vessel 11. In this example, the annular groove 5 and the first discharge port 52 are formed to open on the upper side of the first annular portion 22 in the first state. Therefore, the first discharge port 52 is located above the inclined portion 233 that forms the first annular portion 22. The first discharge port 52 discharges N gas into the first gap 41 as described below. ２ For the purpose of supplying gas and preventing the intrusion of processing gas, the first discharge port 52 opens below the upper end of the upper structure 2 at the processing position (which is also the upper end of the main body 21). Note that in this example, the first discharge port 52 opens at a height above the area surrounded by the main body 21 and the first annular portion 22 at the processing position as shown in FIG.

[0032] The second gas supply mechanism 53 supplies an inert gas, such as nitrogen (N ２ ) gas supply mechanism, ２The gas supply mechanism 53 includes a gas supply source, a valve for opening and closing the supply pipe 532, a flow rate adjusting unit for adjusting the flow rate of the gas, etc. In this example, as shown in Figures 3 and 5, a plurality of first discharge ports 52 are formed in the annular groove 5 at equal intervals in the circumferential direction, and each of the first discharge ports 52 is connected to a common second gas supply mechanism 53 via a flow path 531 and a supply pipe 532.

[0033] Furthermore, a third annular portion 54 is formed on the bottom wall 13 of the processing vessel 11, protruding upward from the side of the mounting table 3 relative to the exhaust port 14. As shown in FIG. 4 , the third annular portion 54 is erected on the bottom wall 13 and surrounds the side surface of the mounting table 3 with a small gap between them. The thickness of the upper end of the third annular portion 54 decreases upward, so that the outer peripheral surface of the upper end forms an inclined surface 542 that slopes downward toward the periphery of the processing vessel 11. This inclined surface 542 guides the processing gas from above the mounting table 3 toward the exhaust port 14. The upper end surface of the third annular portion 54 is configured as a flat surface 541 that faces the outer region 232 of the upper structure 2.

[0034] In this example, the flat surface 541 is set to be slightly lower than the upper surface of the mounting table 3 so as not to interfere with the flow of processing gas from above the mounting table 3 toward the exhaust port 14. Thus, when viewed from the exhaust port 14, when the upper structure 2 is in the processing position, the first annular portion 22 is provided on the sidewall 12 side, and the third annular portion 54 is provided on the mounting table 3 side, and is open to a space surrounded by these annular portions 22, 54. Note that the third annular portion 54, the first annular portion 22, and the sidewall 12 of the processing vessel 11, which is the second annular portion, are concentric rings in a plan view as shown in FIG. 3 , and the centers of these annular portions in a plan view are aligned with the center of the mounting table 3.

[0035] The mounting table 3 and the support portion 32 are disposed so as to form a small gap between them and the bottom wall 13 and the recess 131. The gap formed between the third annular portion 54 and the side surface of the mounting table 3 is configured to communicate with the gap formed between the mounting table 3 and the bottom wall 13 and the gap formed between the support portion 32 and the recess 131. Thus, a second gap 42 is formed between the mounting table 3, the bottom wall 13, and the third annular portion 54, and this second gap 42 extends from the lower surface to the side surface of the mounting table 3. As described above, the second gap 42 is formed relatively small to prevent the inflow of processing gas while reducing the amount of inert gas supplied. The size of the second gap 42 (the distance between the lower surface of the mounting table 3 and the upper surface of the bottom wall 13 and the distance between the side surface of the mounting table 3 and the third annular portion 54) is set to, for example, 1 mm or less, preferably 0.5 mm or less.

[0036] The second gap 42 thus formed is supplied with an inert gas, such as N 2 , from a third gas supply mechanism 55 . ２ The second gap 42 is connected to a supply pipe 552 provided outside the processing chamber 11 via a flow path 551, and the base end of the supply pipe 552 is connected to a third gas supply mechanism 55. The third gas supply mechanism 55 supplies N ２ This mechanism includes a gas supply source, a valve for opening and closing the supply pipe 552, a gas flow rate regulator, and the like.

[0037] Furthermore, a transfer port 18 is formed in the side wall 12 of the processing vessel 11, through which the wafer W is transferred into and out of the processing vessel 11 when the upper structure 2 is in the transfer position, and this transfer port 18 is configured to be freely opened and closed by a gate valve 19. Furthermore, the processing vessel 11 is provided with transfer pins that can be raised and lowered to transfer the wafer W between an external transfer mechanism (not shown) and the mounting table 3.

[0038] The substrate processing apparatus 1 having the above-described configuration includes a control unit 100. The control unit 100 is configured by a computer including a storage unit, a memory, and a CPU that stores a program. The program is configured to output control signals from the control unit 100 to each unit of the substrate processing apparatus 1 for performing control necessary for processing the wafer W. Such a program is stored in a storage unit of the computer, such as a flexible disk, a compact disk, a hard disk, an MO (magneto-optical disk), or a nonvolatile memory, and is read from the storage unit and installed in the control unit 100. The control unit 100 supplies a processing gas from the first gas supply mechanism 26, an inert gas (N ) from the second gas supply mechanism 53, and a third gas supply mechanism 55. ２ The start and stop of supply of the gas and the adjustment of the flow rate are also carried out based on commands from the control unit 100.

[0039] <Substrate Processing Method> An example of a substrate processing method performed by the substrate processing apparatus 1 will now be described. First, in the second state in which the upper structure 2 is disposed at the transfer position, a wafer W is loaded into the processing vessel 11 through the transfer port 18 and placed on the mounting table 3. In this state, no processing gas is supplied into the processing vessel 11. Next, the upper structure 2 is lowered to the processing position to set the first state, the processing vessel 11 is evacuated through the exhaust port 14 to adjust to a preset pressure, and the wafer W on the mounting table 3 is heated by the heater 31 to a set processing temperature between 400°C and 800°C.

[0040] Then, the source gas and the reactive gas are alternately supplied from the first gas supply mechanism 26 to the processing space 10 via the upper structure 2 in the order of source gas → replacement gas → reactive gas → replacement gas, and a thin film is formed on the wafer W by ALD. At this time, the flow of the processing gas within the processing vessel 11 is regulated by the first annular portion 22 of the upper structure 2. Furthermore, when the processing gas is supplied from at least the first gas supply mechanism 26 into the processing vessel 11, N 2 is supplied from the second gas supply mechanism 53 and the third gas supply mechanism 55 to the first gap 41 and the second gap 42, respectively. ２ Supply gas.

[0041] The gas flow in the processing chamber 11 will be described with reference to FIG. 6. In this figure, the processing gas supplied from the first gas supply mechanism 26 is indicated by a solid line, and the N 2 gas supplied from the second gas supply mechanism 55 and the third gas supply mechanism 56 is indicated by a solid line. ２ The gases are indicated by dashed lines. The processing vessel 11 is exhausted by the exhaust mechanism 16 through the exhaust port 14, so that the processing gas supplied into the processing space 10 flows from the gas flow path 17 formed on the side of the mounting table 3 so as to surround the mounting table 3 toward the exhaust port 14 surrounded by the first annular portion 22 and the third annular portion 54. Some of the processing gas does not head toward the exhaust port 14 but continues straight above the exhaust port 14, but collides with the first annular portion 22, changes course, and heads toward the exhaust port 14.

[0042] Furthermore, when the upper structure 2 is in the first state and at the processing position, the lower end of the first annular portion 22 is located below the upper surface of the mounting table 3. Therefore, as described above, the processing gas that is supplied from the upper structure 2 toward the mounting table 3 and then flows toward the outside of the mounting table 3 reliably collides with the first annular portion 22. In this way, the processing gas either flows directly into the exhaust port 14 or has its flow direction changed by the first annular portion 22 before flowing into the exhaust port 14.

[0043] On the other hand, a first gap 41 between the upper structure 2 and the side wall 12 and a second gap 42 between the mounting table 3 and the bottom wall 13 are filled with N ２ Gas is supplied, and these N ２ The gas also flows toward the exhaust port 14. The first gap 41 is formed along the side surface of the upper structure 2 so as to surround the upper structure 2, and the N ２ The gas flows downward while diffusing circumferentially along the side surface of the upper structure 2 and is discharged from the exhaust port 14 through the gap at the lower end of the first annular portion 22 .

[0044] The second gap 42 is formed to surround the stage 3, and the N ２The gas flows upward while diffusing in the circumferential direction along the side surface of the mounting table 3 and flows toward the exhaust port 14 through the gap at the upper end of the third annular portion 54. In this way, in the processing chamber 11, N 2 flows from the entire circumference of the lower end of the first annular portion 22 of the upper structure 2 toward the exhaust port 14. ２ The gas is discharged, and N ２ The gas is discharged toward the exhaust port 14 .

[0045] The first and second gaps 41 and 42 are continuously supplied with N gas during the period when the processing gases, i.e., source gas, reactive gas, and replacement gas, are supplied into the processing space 10. ２ As a result, the processing gas is N 2 gas continuously supplied to the first and second gaps 41 and 42. ２ The N is guided along with the gas flow toward the exhaust port 14. ２ The gas flow prevents the processing gas from entering the first gap 41 and the second gap 42. Since the first and second gaps 41 and 42 are relatively narrow spaces, the probability that the processing gas will not head toward the exhaust port 14 and will enter the first and second gaps 41 and 42 is originally small. ２ By supplying the gas, the processing gas can be reliably prevented from entering the gaps 41 and 42 .

[0046] N in the first gap 41 ２ The gas flow will be described in more detail. N 2 gas is supplied to the annular groove 5 through the first outlet 51. ２ The gas diffuses in the annular groove 5. ２ The gas flows in the circumferential direction along the annular groove 5 so as to surround the first gap 41. Then, the N ２ Gas flows downward through the first gap 41 from the entire annular groove 5, and flows from below the first annular portion 22 toward the center of the processing vessel 11. Therefore, the annular groove 5 allows N gas to be uniformly distributed throughout the entire circumferential direction of the first gap 41. ２ As the gas is supplied, the pressure in the first gap 41 increases, and N 2 is supplied from the entire lower part of the first annular portion 22 at a sufficient flow rate. ２ Gas is supplied.

[0047] Therefore, even if the process gas flows into the first gap 41 and tries to pass through it by rising, the process gas is prevented from passing through the entire circumferential direction of the first gap 41, and therefore the process gas can be prevented from diffusing into the process vessel 11. This prevents the process gas from diffusing and remaining in the process vessel 11, and reliably prevents the process gas from flowing out of the process vessel 11 through the transfer port 18 when the wafer W is unloaded. In this example, the first discharge ports 52 are formed in the annular groove 5 evenly in the circumferential direction, so that the N ２ By supplying gas to increase the pressure at each portion in the circumferential direction, it is possible to prevent the processing gas from passing through.

[0048] Furthermore, in this example, the first discharge port 52 opens above the area surrounded by the first annular portion 22 and the main body portion 21 in the first state, so that N ２ The gas flows a relatively long distance to the lower end of the first annular portion 22. Therefore, the N ２ The gas spreads uniformly in the circumferential direction of the first annular portion 22 and is discharged uniformly from the entire circumference of the lower part of the first annular portion 22 toward the center of the processing vessel 11. Therefore, the processing gas is more reliably prevented from flowing into the first gap 41.

[0049] In this way, N ２ By discharging the gas, N ２ Some of the gas flows upward through the first gap 41 and diffuses into the processing chamber 11. However, the N ２ As described above, most of the gas flows downward through the first gap 41 when exhausted from the exhaust port 14, and only a small amount flows upward. In addition, since the gas is an inert gas, there is no impact from it flowing out of the processing vessel 11 when the wafer W is unloaded.

[0050] Modification of the First Embodiment A modification of the above-described embodiment will be described with reference to FIG. 7 . In this example, the annular groove 5A is formed in the first annular portion 22, rather than in the sidewall 12 of the second annular portion. The annular groove 5A faces the first gap 41 and is formed around the entire circumference of the first annular portion 22. In this example, the annular groove 5A is configured by forming a recess 510 in the outer surface of the first annular portion 22 and includes a first outlet port 521 that opens into the annular groove 5A. For example, the upper structure 2 is provided with a flow path 533 that communicates with the annular groove 5A, and its tip opens into the annular groove 5A to form the first outlet port 521. The base end of the flow path 533 is connected to the second gas supply mechanism 53 via a supply pipe 534 provided outside the processing vessel 11.

[0051] Even in this configuration, N gas is supplied to the first gap 41 through the annular groove 5A at least during the period when the processing gas is supplied into the processing vessel 11. ２ Gas is supplied through the annular groove 5A. ２ The gas is sufficiently supplied to each portion in the circumferential direction of the first gap 41, and the processing gas is prevented from passing through the corresponding region. This prevents the processing gas from diffusing into the processing vessel 11 through the first gap 41 and flowing out of the processing vessel 11 when the wafer is unloaded.

[0052] In this way, N ２ The gas may be supplied from either the first annular portion 22 or the second annular portion (the side wall 12 of the processing vessel 11). ２ The gas supply pipe 534 must be raised and lowered together with the upper structure 2, which may limit the design of the apparatus and increase costs. In this respect, it is advantageous to provide the first discharge port 52 on the side wall 12 of the processing vessel 11, where no raising and lowering operation is performed.

[0053] According to the above-described embodiment, in the substrate processing apparatus 1 in which the distance between the upper structure 2 and the mounting table 3 is changed, an inert gas, N , is introduced into the first gap 41 formed between the first annular portion 22 of the upper structure 2 and the second wall portion formed by the sidewall 12 of the processing vessel 11. ２Therefore, it is possible to reliably prevent the processing gas from diffusing into the processing vessel 11 through the first gap 41. In addition, the first annular portion 22 is provided in the upper structure 2 so that its lower end is located closer to the end of the bottom wall than the exhaust port 14, and N is supplied to the first gap 41 formed between the first annular portion 22 and the side wall 12 (second wall portion). ２ By supplying the gas, exhaust of the processing gas can be promoted and the processing gas can be prevented from flowing around into the first gap 41 .

[0054] Furthermore, the first gap 41 formed between the upper structure 2 and the side wall 12 of the processing vessel 11 is a narrow space, and by providing the upper structure 2 so as to be freely raised and lowered, the second gap 42 formed between the mounting table 3 and the bottom wall 13 of the processing vessel 11 can be set to a narrow space. ２ Since gas is supplied, N ２ While reducing the gas flow rate, the processing gas can be prevented from entering these gaps 41 and 42 , and the processing gas can be prevented from diffusing into the processing vessel 11 .

[0055] If the exhaust port 14 is open to the first gap 41, the amount of exhaust air at the portion of the first gap 41 where the exhaust port 14 opens increases, and as described above, the amount of N ２ In order to prevent the process gas from flowing around into the first gap 41, the first annular portion 22 is configured to be close to the bottom wall 13 of the process vessel 11 at a position closer to the edge of the process vessel 11 than the exhaust port 14, so that the pressure loss of the process gas at this position is high. For this reason, the lower end of the first annular portion 22 is configured to be closer to the edge of the bottom wall 13 than the exhaust port 14 in a plan view. This configuration will be further explained below.

[0056] In the above example, the layout is such that the inner peripheral edge of the lower end of the first annular portion 22 is located closer to the periphery of the processing vessel 11 than the exhaust ports 14 in a plan view. However, the layout is not limited to this; the lower end of the first annular portion 22 may be located closer to the edge of the bottom wall 13 than the exhaust ports 14 in a plan view. For example, the first annular portion 22 may be formed wider than in the above example, and the inner peripheral edge of the lower end of the first annular portion 22 may be located slightly closer to the center of the processing vessel 11 than in the above example, thereby overlapping with the exhaust ports 14. In other words, a portion of the lower end of the first annular portion 22 may overlap with the exhaust ports 14 in a plan view, as long as the outer peripheral edge of the lower end of the first annular portion 22 is located at least outside the exhaust ports 14 in a plan view.

[0057] However, in order to more reliably prevent the process gas from flowing into the first gap 41, it is preferable that the area of ​​the first annular portion 22 adjacent to the bottom wall 13 is large, and therefore it is preferable that the lower end of the first annular portion 22 does not overlap the exhaust port 14 in plan view as in the example described above. Note that portions of the first annular portion 22 other than the lower end may overlap the exhaust port 14 as shown in the example of the inclined portion 233 of the first annular portion 22, or may not overlap. Also, in this example, N ２ When supplying gas, the entire first discharge port 52 opens below the upper end of the upper structure 2, but it is also possible to configure the first discharge port 52 so that only the lower side thereof opens below the upper end of the upper structure 2.

[0058] Second Embodiment Next, a second embodiment of the substrate processing apparatus 1A will be described with reference to FIGS. 8 and 9. In this example, the driving mechanism 7 raises and lowers the mounting table 3 to change the distance between the upper structure 2A and the mounting table 3. However, to avoid the problems described in the comparative example, a portion of the bottom wall 63 of the processing vessel 6 also moves together with the mounting table 3. The following description will focus on differences from the first embodiment, and components configured similarly to those in the first embodiment will be denoted by the same reference numerals and will not be described again.

[0059] The processing vessel 6 includes an upper wall 61, a side wall 62, and a bottom wall 63. The bottom wall 63 is divided into a first bottom wall 64 and a second bottom wall 65. In a plan view, the first bottom wall 64 and the second bottom wall 65 are circular and annular, respectively, and are concentrically arranged. The first bottom wall 64, excluding its central portion, is disposed above the second bottom wall 65, and the first and second bottom walls 64 and 65 overlap each other in a plan view. The peripheral edge of the second bottom wall 65 is located outside the first bottom wall 64. The side wall 62 extends from the edge of the second bottom wall 65. The side wall 62 is provided with a transfer port 621 for loading and unloading a wafer W, which can be opened and closed by a gate valve 622.

[0060] The first bottom wall 64 is provided with an exhaust port 66, a second annular portion 67, and the mounting table 3, and the mounting table 3 is configured similarly to the first embodiment. The first bottom wall 64 has a flat portion 641 facing the second bottom wall 65 and a recessed portion 642 formed to protrude downward from the flat portion 641 and provided to surround the support portion 32 of the mounting table 3, and the flat portion 641 extends along the underside of the mounting table 3 to the outside. In this way, the first bottom wall 64 is configured to cover the bottom surface of the mounting table 3 and the side surface of the support portion 32 via a gap and to support the bottom surface of the support portion 32. The recessed portion 642 is inserted into an opening provided in the second bottom wall 65, and the lower side of the recessed portion 642 is located below the second bottom wall 65.

[0061] The exhaust port 66 is formed in the flat portion 641 of the first bottom wall 64 so as to open to the outside of the mounting table 3 in a plan view. Although only one exhaust port 66 is illustrated in FIGS. 8 and 9 , a plurality of exhaust ports 66 are formed around the mounting table 3 in this example. Each exhaust port 66 is connected to a bellows 68 provided on the lower surface of the second bottom wall 65 via an exhaust pipe 661 extending downward within the processing chamber 6. The lower end of the bellows 68 is connected to the exhaust mechanism 16 shared by each exhaust port 66 via an exhaust path 15. In addition, a second annular portion 67 is formed in the first bottom wall 64 closer to the end of the first bottom wall 64 than the exhaust port 66 in a plan view, more specifically, on the peripheral edge of the first bottom wall 64, so as to extend upward from the first bottom wall 64.

[0062] The recess 642 of the first bottom wall 64 is connected to the drive mechanism 7 below the processing vessel 11 and configured to lift and lower the mounting table 3 via the first bottom wall 64. More specifically, the mounting table 3 and the first bottom wall 64 are lifted and lowered in the vertical direction relative to the second bottom wall 65 and the upper structure 2A. In this example, the drive mechanism 7 is made of a ball screw mechanism, and the upper end of a ball screw 71 abuts against the lower surface of the second bottom wall 65 and has a lower end connected to a motor 72. An elevator 73 provided on the ball screw 71 is connected to the recess 642.

[0063] Further, near the recess 642 of the first bottom wall 64, the lower surface of the first bottom wall 64 and the upper surface of the second bottom wall 65 are connected by a bellows 74, which is an expandable connecting member. In this manner, the mounting table 3 is raised and lowered together with the first bottom wall 64 by the driving mechanism 7, and moves between the processing position (first state) shown in FIG. 8 and the transfer position (second state) shown in FIG. 9. At this time, as the mounting table 3 is raised and lowered, the bellows 68 and 74 expand and contract, maintaining the airtightness inside the processing vessel 11. In this manner, the first bottom wall 64 and the second bottom wall 65 are connected while maintaining the airtightness inside the processing vessel 11, and constitute the bottom wall 63 of the processing vessel 6.

[0064] An upper structure 2A is supported on the second bottom wall 65. The upper structure 2A is provided below the upper wall 61 of the processing vessel 6 and separated from the upper wall 61 so as to face the mounting table 3, and includes a main body 21, a first annular portion 22, and a second outlet port 24 that are configured similarly to the first embodiment. In this example, in order to avoid the influence of thermal expansion, which will be described later, the upper structure 2A including the first annular portion 22 and the first bottom wall 64 including the second annular portion 67 are made of the same material, for example, metal.

[0065] In this embodiment, the upper structure 2A has a peripheral portion extending downward to form a support portion 28, which is configured in an annular shape. The support portion 28 is located outside the second annular portion 67, and its lower end is connected to the second bottom wall 65. The support portion 28 is provided away from the side wall 62 of the processing vessel 6 and is configured as a separate member from the side wall 62. An opening 281 for loading and unloading the wafer W is formed in the support portion 28 at a position overlapping with the transfer port 621 of the processing vessel 6 in a side view.

[0066] In this example, the first annular portion 22 is provided to extend downward from the main body 21 so as to be located near the inner surface of the second annular portion 67. The lower end of the first annular portion 22 is located closer to the end of the first bottom wall 64 than the exhaust port 66 in plan view. More specifically, in this example, the inner peripheral edge of the lower end of the first annular portion 22 overlaps with the end of the exhaust port 66 on the peripheral side of the processing vessel 6 in plan view.

[0067] 8, when the mounting table 3 is in the processing position (first state), a first gap 81 is formed between the first annular portion 22 and the second annular portion 67. Also, as shown in Fig. 10, the first annular portion 22 has an annular groove 83 formed therein, for example, facing the first gap 81 and extending around the entire circumference of the first annular portion 22, and a first outlet port 82 opens into the annular groove 83. The first outlet port 82 is connected to the second gas supply mechanism 53 via a flow path 821 and a supply pipe 532. Thus, N gas is supplied from the second gas supply mechanism 53 to the first gap 81. ２ In this example, the flow passage 821 is formed in the support portion 28 and the second bottom wall 65.

[0068] Furthermore, a third annular portion 84 is formed on the first bottom wall 64 closer to the mounting table 3 than the exhaust port 66 so as to protrude upward from the first bottom wall 64. The third annular portion 84 is provided so as to surround the mounting table 3 with a small gap therebetween, and a second gap 85 is formed by the third annular portion 84, the first bottom wall 64, and the mounting table 3. N gas is supplied to this second gap 85 from the third gas supply mechanism 55 via a supply pipe 552 and a flow path 551. ２The sizes of the first gap 81 and the second gap 85 are set to be the same as those in the first embodiment, for example.

[0069] In this embodiment, the mounting table 3 is also placed at the transfer position (second state), and the wafer W is loaded into the processing chamber 6 through the opening 281 and the transfer port 621 and placed on the mounting table 3. After that, after the mounting table 3 is set to the processing position (first state), N gas is introduced into the first gap 81 and the second gap 85 at least when the processing gas is being supplied into the processing chamber 6. ２ As a result, similar to the first embodiment, the processing gas is exhausted from the processing vessel 6 through the exhaust port 66 without entering the first gap 81 or the second gap 85. This prevents the processing gas from diffusing into the processing vessel 6 through the first gap 81 or the second gap 85, and prevents the processing gas from flowing out of the processing vessel 6 when the wafer is unloaded.

[0070] Incidentally, when the mounting table 3 reaches a relatively high temperature during wafer W processing, the upper structure 2A and the first bottom wall 64 thermally expand due to radiant heat from the mounting table 3, displacing the positions of their respective peripheral edges away from the center of the processing vessel 6 in a plan view. If the upper structure 2A is connected to the lower surface of the top wall 61 of the processing vessel 6 and the upper wall 61 and the upper structure 2 are made of different materials, the amount of displacement of the peripheral edge of the upper structure 2A described above will be affected by the displacement due to the thermal expansion of the top wall 61. Furthermore, because the top wall 61 faces the space within the temperature-controlled clean room in which the substrate processing apparatus 1A is installed, suppressing thermal expansion may affect the amount of displacement of the peripheral edge of the upper structure 2A.

[0071] As will be described later, even when the upper wall 61 is configured as the upper structure 2A, thermal expansion is similarly suppressed due to the influence of the temperature in the clean room. However, as described above, the upper structure 2A is supported by the support portion 28, which is separate from the side wall 62 of the processing vessel 6, and is therefore formed as a separate body from the upper wall 61. Therefore, the amount of thermal expansion of the upper structure 2A is less likely to be affected by the above-mentioned upper wall 61.

[0072] If the peripheral edges of the upper structure 2A and the first bottom wall 64 are displaced due to thermal expansion, the positions of the first annular portion 22 provided on the upper structure 2A and the second annular portion 67 provided on the first bottom wall 64 relative to the center of the processing vessel 6 in a plan view also change. However, since the amount of thermal expansion of the upper structure 2A is not easily affected by the top wall 61 as described above and the upper structure 2A and the first bottom wall 64 are made of the same material and have equivalent amounts of thermal expansion, the amounts of change in the positions of the first annular portion 22 and the second annular portion 67 are equivalent or roughly equivalent. Therefore, the change in the width of the first gap 81 is suppressed, preventing the process gas from leaking easily. Furthermore, in this embodiment, since the upper structure 2A is fixed to the second bottom wall 65, the process gas and N ２ There is no need to raise and lower the gas supply pipes 261 and 532, which increases the degree of freedom in the design of the device.

[0073] <Modification of the Second Embodiment> In this example, as shown in FIG. 11 , the second annular portion 67 is spaced apart from the first gap 81 by N. ２ In this case, for example, N gas is supplied to the second annular portion 67 toward the first gap 81. ２ a first outlet 86 for discharging gas; ２ On the other hand, for example, the second bottom wall 65 is connected to the second gas supply mechanism 53 (not shown in FIG. 11 ) via the supply pipe 532, and a flow path 862 connecting to the supply pipe 532 is formed in the second bottom wall 65 and the support portion 28.

[0074] In the processing chamber 6, a flow path 861 in the second annular portion 67 and a flow path 862 in the second bottom wall 65 and the support portion 28 are connected by, for example, a flexible supply pipe 863, so that N 2 is supplied from the second supply mechanism 53 to the first discharge port 86. ２ Even with this configuration, when the processing gas is supplied to the processing chamber 6, N ２ Since the gas is supplied, the diffusion of the processing gas into the processing vessel 6 is prevented, and the outflow of the processing gas to the outside of the processing vessel 6 when the wafer is unloaded is prevented, similar to the above-described embodiment.

[0075] Third Embodiment Next, a third embodiment of the substrate processing apparatus 1B will be described with reference to FIG. 12 . In this example, the processing vessel 9 is configured by the upper structure 2A and the second bottom wall 65 of the second embodiment. In this configuration example, the upper structure 2A forms the top wall of the processing vessel 9, and its support portion 28 forms the side wall of the processing vessel 9. The support portion 28 is provided with a transfer port 91 for the wafer W that can be opened and closed by a gate valve 92. The other configuration is the same as in the second embodiment, and the same components are designated by the same reference numerals.

[0076] Even with this configuration, similarly to the second embodiment, the mounting table 3 is placed at the transfer position (second state), and the wafer W is loaded into the processing chamber 9 through the transfer port 91 and placed on the mounting table 3. Thereafter, the mounting table 3 is set at the processing position (first state), and when the processing gas is supplied into the processing chamber 9, N 2 is supplied into the first gap 81 and the second gap 85. ２ This prevents the processing gas from diffusing into processing vessel 9 through first gap 81 and second gap 85, and prevents the processing gas from leaking out of processing vessel 9 when the wafer is unloaded.

[0077] In this configuration, the processing vessel 9 is configured by the upper structure 2A and the second bottom wall 65, which is a simpler structure than the second embodiment and has a smaller number of components, which is advantageous in terms of manufacturing costs. Note that the first annular portion 22 in this third embodiment is an example in which a portion of it overlaps with the exhaust port 66 in a plan view.

[0078] In the substrate processing apparatus disclosed herein, it is not necessary to form an annular groove facing the first gap. Instead of forming an annular groove, a plurality of first discharge ports may be formed facing the first gap and arranged in a circumferential direction. In other words, the first discharge ports are not limited to opening into the annular groove, as long as the number and shape of the first discharge ports are appropriately set so that gas can be sufficiently supplied to the entire circumferential direction of the first gap. Furthermore, the shape of the annular groove is not limited to the above-mentioned shape, and the longitudinal cross section may be appropriately formed into a substantially semicircular shape, for example.

[0079] Furthermore, the shape of the first annular portion is not limited to the above, as long as its lower end is located closer to the edge of the bottom wall of the processing vessel than the exhaust port in a plan view. For example, the surface of the first annular portion facing the mounting table may be formed as an inclined surface. For example, the first annular portion may be configured to taper downward, so that the surface of the first annular portion facing the mounting table becomes an inclined surface that slopes downward from the upper end to the lower end of the first annular portion toward the periphery of the processing vessel.

[0080] Furthermore, the upper structure of the present disclosure does not necessarily have to be configured as a gas supply unit, as long as it is configured to form a processing space for the wafer W between itself and the mounting table. For example, the upper structure may be configured as an upper electrode that generates plasma between itself and the mounting table, which serves as a lower electrode. Then, a processing gas may be supplied to the processing space formed by the upper structure and the mounting table using a gas nozzle or the like.

[0081] In the above-described embodiment, the substrate processing apparatus is an apparatus that performs a film formation process by ALD, but it may also be an apparatus that performs plasma ALD. Furthermore, it is not limited to an apparatus that performs a film formation process. Furthermore, the shape of the processing space in the processing vessel of the substrate processing apparatus described above, and the number and layout of exhaust ports are merely examples, and are not limited to the above-described configuration. Furthermore, the inert gas supplied to the first gap and the second gap may be N. ２ The upper structure and the mounting table may be placed in the first state (processing position) and an inert gas may be supplied to the first gap and the second gap to promote evacuation of the processing vessel without supplying a processing gas into the processing vessel.

[0082] So far, we have used wafers as an example of substrates, but the substrates processed in the processing vessel include, in addition to wafers, substrates used to manufacture flat panel displays, substrates used to manufacture exposure masks used in photolithography, and dummy substrates processed for the purpose of testing or setting processing parameters in the substrate processing apparatus.

[0083] 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.

[0084] W: Wafer 1, 1A, 1B: Substrate processing apparatus 11, 6, 9: Processing vessel 13, 63: Bottom wall 14, 66: Exhaust port 3: Mounting table 26: First gas supply mechanism 2, 2A: Upper structure 21: Main body 22: First annular portion 27, 7: Drive mechanism 12, 67: Second annular portion 41, 81: First gap 53: Second gas supply mechanism

Claims

a first gas supply mechanism that supplies a process gas used to process the substrate placed on the mounting table into the process vessel; an upper structure that includes a main body provided above the mounting table so as to face the mounting table, and a first annular portion that extends downward from the main body to regulate the flow of the process gas, the first annular portion having a lower end located closer to the edge of the bottom wall than the exhaust port in a plan view; a drive mechanism that changes the distance between the mounting table and the upper structure; a second annular portion that extends upward from the bottom wall of the process vessel and surrounds the first annular portion; and a second gas supply mechanism that supplies an inert gas to a first gap formed by the upper structure and the second annular portion so as to communicate with the exhaust port.

2. The substrate processing apparatus of claim 1, wherein the drive mechanism changes the distance between the upper structure and the mounting table between a first distance and a second distance longer than the first distance, and in a first state where the distance is the first distance, the processing gas is supplied from the first gas supply mechanism into the processing vessel, and in a second state where the distance is the second distance, the processing gas is not supplied from the first gas supply mechanism into the processing vessel.

3. The substrate processing apparatus according to claim 2, wherein in the first state, the lower end of the first annular portion is positioned below the upper surface of the mounting table.

4. A substrate processing apparatus as described in claim 1, wherein one of the first and second annular portions has an annular groove formed around the entire circumference of the annular portion facing the first gap, and a first discharge port opening into the annular groove for discharging the inert gas.

5. The substrate processing apparatus according to claim 1, wherein the second gas supply mechanism supplies an inert gas to the first gap at least when the processing gas is supplied from the first gas supply mechanism into the processing vessel.

6. A substrate processing apparatus according to claim 1, further comprising: a third annular portion that protrudes upward from the bottom wall on the side of the stage closer to the stage than the exhaust port and surrounds the stage; and a third gas supply mechanism that supplies an inert gas to a second gap formed by the third annular portion, the bottom wall, and the stage.

7. A substrate processing apparatus according to claim 6, wherein the second annular portion forms a side wall of the processing vessel, the upper structure has a second outlet port for discharging the processing gas, and the drive mechanism raises and lowers the upper structure relative to the mounting table.

8. A substrate processing apparatus as described in claim 7, wherein the distance between the upper structure and the mounting table is changed by the drive mechanism between a first distance and a second distance longer than the first distance, the processing gas is supplied from the first gas supply mechanism into the processing vessel in a first state where the distance is the first distance, and the processing gas is not supplied from the first gas supply mechanism into the processing vessel in a second state where the distance is the second distance, and a first discharge port for discharging the inert gas is provided so as to open below an upper end of the main body in the first state.

9. The substrate processing apparatus according to claim 8, wherein the first discharge port is provided in a sidewall of the processing vessel.

10. A substrate processing apparatus as described in claim 6, wherein the bottom wall of the processing vessel is divided into a first bottom wall and a second bottom wall, the exhaust port, the second annular portion and the mounting table are provided on the first bottom wall, the upper structure having a second discharge port for discharging the processing gas is supported on the second bottom wall, the drive mechanism raises and lowers the first bottom wall and the mounting table relative to the upper structure and the second bottom wall, and an expandable connecting member is provided to connect the first bottom wall and the second bottom wall to make the inside of the processing vessel airtight.

11. A substrate processing apparatus according to claim 10, wherein the upper structure is separate from the top wall of the processing vessel and is provided at a distance from the top wall, and is supported by the second bottom wall by a support portion separate from the side wall of the processing vessel.

12. A substrate processing method comprising: placing a substrate on a mounting table provided within a processing vessel; evacuating the processing vessel through an exhaust port that opens to the outside of the mounting table in a plan view in the bottom wall of the processing vessel; supplying a processing gas from a first gas supply mechanism into the processing vessel to process the substrate placed on the mounting table; regulating the flow of the processing gas by a first annular portion of an upper structure comprising: a main body provided above the mounting table so as to face the mounting table; and a first annular portion extending downward from the main body and having a lower end located closer to the edge of the bottom wall than the exhaust port in a plan view; changing the distance between the mounting table and the upper structure by a drive mechanism; and supplying an inert gas by a second gas supply mechanism to a first gap formed by the upper structure so as to communicate with the exhaust port and a second annular portion extending upward from the bottom wall of the processing vessel and surrounding the first annular portion.

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