Apparatus for performing film formation process on substrate and method for exhausting process gas from the apparatus for performing film formation process on substrate

Abstract

To provide a technology for suppressing a deterioration in gas separation performance and a deterioration in exhaust speed in exhausting first processing gas and second processing gas from a neighborhood of a rotation center of a rotary table through respectively different exhaust paths.SOLUTION: A device includes: a rotating shaft exhaust path connected to a rotary table to rotate it and formed with an exhaust path formed therein, for mounting and rotating a plurality of substrates on the rotary table to alternatively pass them through a supply region of first processing gas and a supply region of second processing gas to form a thin film on the substrates; and a ceiling surface side exhaust path formed so as to vertically penetrate a member constituting a central area of a top plate of a vacuum container. The first processing gas is exhausted to the rotation shaft exhaust path through a first exhaust port, and second processing gas is exhausted to the ceiling surface side exhaust path through a second exhaust path.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present disclosure relates to an apparatus for performing a film forming process on a substrate, and a method for exhausting a process gas from the apparatus for performing a film forming process on a substrate. [Background technology]

[0002] As one of the techniques for forming a thin film on a semiconductor wafer (hereinafter referred to as "wafer"), which is a substrate, there is known the ALD (Atomic Layer Deposition) method, in which a source gas and a reactive gas are sequentially supplied to the surface of the wafer to deposit a reaction product. As a film forming apparatus for performing a film forming process using this ALD method, for example, Patent Document 1 describes a configuration in which a rotary table for arranging and revolving a plurality of wafers in the circumferential direction is provided in a vacuum chamber. In this configuration, the wafer passes alternately between a source gas supply region and a reactive gas supply region by rotating the rotary table, and thus a thin film is formed on the wafer. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] JP 2018-56300 A Summary of the Invention [Problem to be solved by the invention]

[0004] The present disclosure provides a technology that suppresses a decrease in gas separation performance and a decrease in exhaust speed when exhausting a first process gas and a second process gas through different exhaust paths from near the center of rotation of a rotary table. [Means for solving the problem]

[0005] The present disclosure provides an apparatus for performing a film formation process on a substrate, comprising: a rotary table that is provided in a vacuum chamber, on one side of which the plurality of substrates are placed, and that rotates about a rotation center to revolve the plurality of substrates around the rotation center; a separation region including a separation gas supply unit for supplying a separation gas, the separation gas supply unit being provided between a first processing region to which a first processing gas that adsorbs to the substrate is supplied and a second processing region to which a second processing gas that reacts with the first processing gas to form a thin film on the surface of the substrate is supplied in order to separate the atmospheres of these processing regions in the rotation direction, and main ceiling surfaces being provided on both sides of the separation gas supply unit in the rotation direction and for forming a separation gas gap between the separation gas supply unit and the turntable through which the separation gas flows; a central region having a central ceiling surface around the rotation center, the central ceiling surface forming a central gap between the rotation table and the central ceiling surface and communicating with the separation gas gap, in order to separate atmospheres of the first processing region and the second processing region; a rotary shaft exhaust passage including a cylindrical body connected to the rotary table for rotating the rotary table around the rotation center and having an exhaust passage formed therein; A ceiling surface side exhaust passage formed so as to vertically penetrate the member constituting the central region; The exhaust gas supply system is characterized in that it comprises a first exhaust port that exhausts the first process gas discharged from the first process region to one side exhaust path, which is the rotating shaft exhaust path or the ceiling surface side exhaust path, and a second exhaust port that exhausts the second process gas discharged from the second process region to the other side exhaust path, which is the rotating shaft exhaust path or the ceiling surface side exhaust path and is different from the one side exhaust path. Effect of the Invention

[0006] According to the present disclosure, when a first processing gas and a second processing gas are exhausted from near the center of rotation of a rotary table through different exhaust paths, a decrease in gas separation performance and a decrease in exhaust speed can be suppressed. [Brief description of the drawings]

[0007] [Figure 1]1 is a vertical cross-sectional side view showing a first embodiment of a film forming apparatus according to the present disclosure. [Diagram 2] FIG. 2 is a plan view showing the film forming apparatus. [Diagram 3] FIG. 2 is an enlarged vertical cross-sectional side view showing a part of the film forming apparatus. [Figure 4] FIG. 2 is a schematic perspective view showing an example of a rotating shaft exhaust path and a ceiling surface side exhaust path provided in the film forming apparatus. [Diagram 5] FIG. 11 is a vertical cross-sectional side view showing the operation of the rotating shaft exhaust passage and the ceiling surface side exhaust passage. [Figure 6] FIG. 4 is a schematic enlarged perspective view showing the operation of the rotating shaft exhaust passage and the ceiling surface side exhaust passage. [Figure 7] FIG. 2 is a vertical sectional side view showing a second embodiment of a film forming apparatus according to the present disclosure. [Figure 8] FIG. 11 is a vertical sectional side view showing a portion of a film forming apparatus according to a third embodiment of the present disclosure. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0008] <First embodiment of the film forming apparatus> An embodiment of an apparatus for performing a film formation process on a substrate according to the present disclosure (hereinafter referred to as a "film formation apparatus") will be described with reference to Figs. 1 to 4. Fig. 1 shows a longitudinal sectional side view cut along the A-A' position in Fig. 2, and Fig. 3 shows a longitudinal sectional side view cut along the B-B' position in the same figure. As shown in Figs. 1 and 2, this film formation apparatus 1 includes a vacuum vessel 10 having a generally circular planar shape. This vacuum vessel 10 includes a top plate 11 and a vessel body 12, and inside the vessel 10, a rotary table 2 made of, for example, quartz is provided, which has a center of rotation at the center of the vacuum vessel 10 and is used to revolve a wafer W around the rotary table.

[0009] 2, a load / unload port 13 is formed in the side wall of the vacuum vessel 10 for transferring the wafer W between an external transfer arm (not shown) and the turntable 2, and this load / unload port 13 is airtightly closed by an openable / closable gate valve 14. The wafer W is transferred between the turntable 2 and the external transfer arm through the load / unload port 13. For this reason, a transfer mechanism (not shown) for penetrating the turntable 2 and lifting the wafer W from the backside is provided below the turntable 2 at the position where the wafer W is transferred.

[0010] <Rotary table> The rotary table 2 is fixed at the center to the core part 21 and is connected to the revolution drive mechanism 23 via the rotary shaft exhaust passage 3 provided in the core part 21 and extending in the vertical direction. The revolution drive mechanism 23 is composed of, for example, a hollow motor or a hollow shaft motor, and rotates the rotary table 2 around the rotation center via the rotary shaft exhaust passage 3. The rotary shaft exhaust passage 3 serves both as the rotary shaft of the rotary table 2 and as an exhaust passage, and an exhaust structure including the rotary shaft exhaust passage 3 will be described later. In FIG. 1, reference numeral 24 denotes a case body that houses the rotary shaft exhaust passage 3 and the revolution drive mechanism 23. A purge gas supply pipe 15 for supplying N2 gas as a purge gas to the area below the rotary table 2 is connected to the case body 24.

[0011] A recess 22 having a diameter of, for example, 300 mm is formed on one side of the turntable 2. The recess 22 has a circular shape as shown in FIG. 2, and is provided at a plurality of locations, for example, six locations, along the rotation direction (circumferential direction) of the turntable 2. The recesses 22 in this example are formed at equal intervals in the circumferential direction of the turntable 2, and the diameter and depth are set so that when the wafer W is stored in the recess 22, the surface of the wafer W and the surface of the turntable 2 are aligned. In this way, when the turntable 2 is rotated around the center of rotation by the revolution drive mechanism 23 via the rotary shaft exhaust path 3, the wafer W placed in the recess 22 revolves around the rotary shaft 3. Here, an example in which the turntable 2 rotates clockwise as shown by the arrow in FIG. 2 will be described, and the rotation direction of the turntable 2 may be referred to as the "rotation direction".

[0012] <First Processing Region and Second Processing Region> As shown in FIG. 2, a first gas nozzle 31 for supplying a first process gas and a second gas nozzle 32 for supplying a second process gas are arranged in the vacuum vessel 10 at intervals in the circumferential direction of the vacuum vessel 10 so as to face the turntable 2. The first process gas is a gas that adsorbs to the wafer W, and the second process gas is a gas that reacts with the first process gas to form a thin film on the surface of the wafer W. Here, dichlorosilane (SiH2Cl2:DCS) gas, which is a raw material gas, is used as the first process gas, and ozone (O3) gas, which is an oxidation gas (reaction gas), is used as the second process gas. Hereinafter, a case in which a silicon oxide film (SiO2 film) is formed by the reaction between these DCS gas and O3 gas will be described as an example.

[0013] The first and second gas nozzles 31, 32 are disposed so as to extend horizontally along the radial direction of the turntable 2 from the outer peripheral wall of the vacuum vessel 10 toward the center, and are each provided so as to straddle an area through which the wafer W passes when the turntable 2 is rotated. The first and second gas nozzles 31, 32 are each composed of a tube with a sealed tip, and have a plurality of gas discharge holes 311, 321 formed on their side surfaces, respectively, as shown in FIG.

[0014] 2, the base end of the first gas nozzle 31 is connected to a DCS gas supply source 313 via a gas supply path 312 equipped with a valve V1 and a flow rate adjustment unit M1. The base end of the second gas nozzle 32 is connected to an O3 gas supply source 323 via a gas supply path 322 equipped with a valve V2 and a flow rate adjustment unit M2. A region to which a first processing gas is supplied from the first gas nozzle 31 via the discharge hole 311 forms a first processing region S1, and a region to which a second processing gas is supplied from the second gas supply nozzle 32 via the discharge hole 321 forms a second processing region S2. For example, an activation mechanism such as an inductively coupled antenna or a microwave antenna for activating O3 gas by plasma may be provided on the top plate 11 of the second processing region S2.

[0015] <Separation area> 2 and 3, two separation regions D1 and D2 are provided between the first processing region S1 and the second processing region S2 to separate the atmospheres of these processing regions S1 and S2. Convex portions 41 and 42 having a roughly sector-shaped planar shape are attached to the top plate 11 of the vacuum vessel 10 in these separation regions D1 and D2, respectively. The lower surfaces of the convex portions 41 and 42 constitute a main ceiling surface 43 above the wafer W placed on the turntable 2 to form a separation gas gap 44 through which a separation gas flows.

[0016] In this example, the main ceiling surfaces 43 of the convex portions 41, 42 are provided close to the turntable 2 so as to face the upper surface of the turntable 2, thus forming the separation gas gap 44 between them and the upper surface of the turntable 2. In FIG. 3, the separation gas gap 44 is drawn large for convenience of illustration. For example, the portions of the convex portions 41, 42 close to the rotation center of the turntable 2 are connected to a central region C of the vacuum vessel 10, which will be described later. In addition, the peripheral edges of the convex portions 41, 42 (portions close to the outer edge of the turntable 2) are bent in an L shape so as to face the outer end surface of the turntable 2 and be slightly spaced from the vessel body 12.

[0017] Separation gas nozzles 33, 34, which constitute separation gas supply units for supplying separation gas, are provided in these separation regions D1, D2. These separation gas nozzles 33, 34 are each made of a tube similar to the first and second gas nozzles 31, 32, and are arranged to extend horizontally from the outer circumferential wall of the vacuum vessel 10 toward the center along the radial direction of the turntable 2. For example, the separation gas nozzles 33, 34 are housed in grooves formed on the lower surfaces of the convex portions 41, 42, and are configured so that main ceiling surfaces 43 are formed on both sides of the nozzles 33, 34 in the rotation direction. The base ends of these separation gas nozzles 33, 34 are connected to separation gas supply sources 332, 342, for example, N2 gas, via gas supply paths 331, 341 equipped with valves V3, V4 and flow rate adjustment units M3, M4, respectively.

[0018] The separation gas nozzles 33 and 34 discharge a separation gas toward the turntable 2 through discharge holes (not shown) formed on the side surfaces of the nozzles 33. The N2 gas discharged from the separation gas nozzle 33 spreads from the nozzle 33 to both sides in the circumferential direction of the vacuum vessel 10 through the separation gas gap 44 on the lower side of the convex portion 41. Then, on the upstream side of the rotation direction of the first gas nozzle 31, a first processing region S1 and a second processing region S2 are separated.

[0019] Furthermore, the N2 gas discharged from the separation gas nozzle 34 spreads from the nozzle 34 to both sides in the circumferential direction of the vacuum vessel 10 through the separation gas gap 44 below the convex portion 42. Then, the first processing region S1 and the second processing region S2 are separated downstream in the rotation direction of the first gas nozzle 31. Thus, the atmospheres of the first processing region S1 and the second processing region S2 are separated by the separation gas nozzles 33, 34 and the separation regions D1, D2 equipped with the convex portions 41, 42.

[0020] <Central area> Furthermore, the vicinity of the rotation center on the top plate 11 of the vacuum vessel 10 is formed as a central region C. In this example, the central region C is formed, for example, in a substantially ring shape in the circumferential direction, continuing from the convex portions 41, 42. As shown in Fig. 3, for example, a ceiling surface 51 of a region close to the convex portions 41, 42 in the central region C is formed at the same height as the lower surfaces (main ceiling surfaces) 4 of the convex portions 41, 42, and a gap 52 communicating with the separation gas gap 44 is formed between the ceiling surface 51 and the rotary table 2.

[0021] The central region C also has a central ceiling surface 54 that forms a central gap 53 between the turntable 2 and the central ceiling surface 54 around the rotation center of the turntable 2, and the central gap 53 communicates with the separation gas gap 44 via the gap 52. In this example, the central ceiling surface 54 is configured as an inclined surface that slopes inward as it moves upward toward the rotation center. As shown by the broken lines in FIG. 3, in the central region C, the separation gas is supplied from the separation regions D1 and D2 to the central gap 53 via the separation gas gap 44 and the gap 52. In this manner, the atmosphere of the first processing region S1 and the second processing region S2 are separated in this region.

[0022] <Exhaust structure> Next, a description will be given of the exhaust structure of the film forming apparatus 1. The film forming apparatus 1 includes a rotary shaft exhaust path 3 provided in the turntable 2, and a ceiling surface side exhaust path 6 formed so as to vertically penetrate a top plate 11 which is a member constituting the central region C. The rotating shaft exhaust passage 3 is formed of a cylindrical body that is open at the upper end and extends vertically. The ceiling surface side exhaust passage 6, as shown in Fig. 4, is formed of a cylindrical body that is open at the lower end as a communication port 62 and extends vertically, and has a protrusion 61 connected to the lower end. This protrusion 61 is a portion that protrudes downward from the central ceiling surface 54 of the top plate 11, and in this example, is formed of the same cylindrical body as the ceiling surface side exhaust passage 6 provided inside the top plate 11.

[0023] 3 and 4, the lower end of the protruding portion 61 is inserted into the opening of the rotating shaft exhaust passage 3 and is configured to communicate with the inside of the rotating shaft exhaust passage 3 via a communication port 62. In this example, the communication port 62 is formed in the lower end of the protruding portion 61, but a configuration in which the lower end of the protruding portion 61 is closed and the communication port 62 is formed in the side surface thereof may also be used. As described above, the rotating shaft exhaust path 3 is configured to be rotatable by the revolution drive mechanism 23, while the ceiling surface side exhaust path 6 is attached and fixed to the top plate 11. In this way, the rotating shaft exhaust path 3 is configured to be rotatable around the protruding portion 61 of the ceiling surface side exhaust path 6. For this reason, a small gap 33 is formed between the inner peripheral surface of the rotating shaft exhaust path 3 and the outer peripheral surface of the protruding portion 61.

[0024] 4, a first exhaust port 71 and a second exhaust port 72 are formed on the side surface of the cylindrical body constituting the protruding portion 61 above the lower end of the protruding portion 61. In this example, the first exhaust port 71 is an exhaust port that exhausts the first processing gas discharged from the first processing region S1 to the rotary shaft exhaust path 3, and the second exhaust port 72 is an exhaust port that exhausts the second processing gas discharged from the second processing region S2 to the ceiling surface side exhaust path 6.

[0025] In this example, as shown in Fig. 2, the first exhaust port 71 is formed so as to open toward a region corresponding to the first processing region S1 surrounded by the separation region D1 and the separation region D2 downstream of the separation region D1 in the rotation direction in a plan view. Meanwhile, the second exhaust port 72 is formed so as to open toward a region corresponding to the second processing region S2 surrounded by the separation region D1 and the separation region D2 upstream of the separation region D1 in the rotation direction in a plan view. Also, as shown in Fig. 3, the first exhaust port 71 and the second exhaust port 72 are each formed at a height position that opens toward the central gap 53 formed in the central region C.

[0026] Furthermore, the protruding portion 61 is provided with a partition plate 63 that divides the internal space thereof. This partition plate 63 guides the first process gas exhausted from the first exhaust port 71 to the rotary shaft exhaust path 3, and guides the second process gas exhausted from the second exhaust port 72 to the ceiling surface side exhaust path 6. For example, as shown in Figures 3 and 4, the partition plate 63 is formed so as to divide the inside of the protruding portion 61 into upper and lower portions, the first exhaust port 71 is formed on the side surface of the protruding portion 61 below the partition plate 63, and the second exhaust port 72 is formed on the side surface of the protruding portion 61 above the partition plate 63.

[0027] The partition plate 63 in this example is formed so as to be bent in a step-like manner, as shown in Figures 3 and 4. For example, the partition plate 63 has a wall portion 631 extending in the vertical direction at a position that divides the area in which the first exhaust port 71 and the second exhaust port 72 are formed, when viewed in a plan view. In addition, the upper end of the wall portion 631 and the inner circumferential surface of the ceiling surface side exhaust path 6, and the lower end of the wall portion 631 and the inner circumferential surface of the ceiling surface side exhaust path 6 are connected by plate-like bodies 632 and 633, respectively, and are configured to divide the internal space of the protruding portion 61.

[0028] 1 and 2, the lower end of the rotating shaft exhaust path 3 is connected to a first vacuum exhaust mechanism 73 via a pressure adjustment unit 731, and the upper end of the ceiling surface side exhaust path 6 is connected to a second vacuum exhaust mechanism 74 via a pressure adjustment unit 741. The vacuum exhaust mechanism is composed of, for example, a vacuum pump, and the pressure adjustment unit is composed of, for example, a butterfly valve. As a result, when the first vacuum exhaust mechanism 73 is operated, the atmosphere in the rotating shaft exhaust path 3 is exhausted downward, and when the second vacuum exhaust mechanism 74 is operated, the atmosphere in the ceiling surface side exhaust path 6 is exhausted upward.

[0029] 1 to continue the description of the film forming apparatus 1, a heating unit 17 is provided around the entire circumference in the space between the turntable 2 and the bottom surface of the vacuum vessel 10 via a quartz cover member 16. The wafer W is heated by heat radiated from the heating unit 17 and heat transferred from the turntable 2 heated by the heating unit 17. In addition, below the heating unit 17, purge gas supply pipes 18 penetrating the bottom surface of the vacuum vessel 10 are provided at multiple locations around the circumference, and N2 gas, which is a purge gas, is supplied through the pipes.

[0030] Furthermore, the film forming apparatus 1 is provided with a control unit 8 consisting of a computer for controlling the operation of the entire apparatus. A program for performing the film forming process described below is stored in the memory of the control unit 8. This program is structured with a group of steps for executing the operation of the apparatus, including exhausting the process gas through the rotary shaft exhaust path 3 and the ceiling surface side exhaust path 6 described below, and is installed by a storage medium such as a hard disk, a compact disk, a magneto-optical disk, a memory card, or a flexible disk.

[0031] <Function of the film forming device> Next, the operation of the above-mentioned film forming apparatus 1, including a method of exhausting the processing gas from the film forming apparatus, will be described. First, the gate valve 14 is opened, and the wafer W transferred between the outside and the turntable 2 is loaded and unloaded through the loading / unloading port 13. For example, after the processed wafer W arranged in each recess 22 of the turntable 2 is unloaded, a wafer W to be processed next is loaded, and an exchange operation of the wafer W is performed. In this exchange operation, the wafer W is loaded and unloaded using an external transfer mechanism (not shown) and the above-mentioned transfer mechanism (not shown). In this way, while intermittently rotating the turntable 2, the six recesses 22 are moved to the loading / unloading positions in sequence, and the operation of loading and unloading the wafer W for each recess 22 is performed.

[0032] When the next wafer W to be processed has been placed in all of the recesses 22, the gate valve 14 is closed, the inside of the vacuum chamber 10 is evacuated by the first and second vacuum exhaust mechanisms 73, 74 and the pressure adjustment units 731, 741, and the wafer W is heated to, for example, 400°C by the heating unit 17 while rotating the turntable 2. Next, while rotating the turntable 2, DCS gas as a first process gas is supplied from the first gas nozzle 31. Furthermore, O3 gas as a second process gas is supplied from the second gas nozzle 32 to perform a film formation process.

[0033] The inside of the vacuum vessel 10 is evacuated by a first vacuum exhaust mechanism 73 via the rotary shaft exhaust path 3, and is also evacuated by a second vacuum exhaust mechanism 74 via the ceiling surface side exhaust path 6. Therefore, in the first processing region S1, the first processing gas (DCS gas) supplied from the first gas nozzle 31 spreads within the first processing region S1 and flows toward a first exhaust port 71 provided near the center of rotation of the turntable 2.

[0034] 5 and 6 show the flow of DCS gas, which is the first processing gas, by solid lines. FIG. 6 is a schematic enlarged perspective view cut at the position EE' in FIG. 5. Thus, the DCS gas flows into the first exhaust port 71 through the gap 52 and the central gap 53 in the central region C. Thus, the DCS gas that has flowed into the central gap 53 from the first processing region S1 side is exhausted to the first exhaust port 71. This DCS gas is guided downward in the space formed by the plate-like body 632 and the wall portion 631 of the partition plate 63, flows toward the rotating shaft exhaust path 3, and is exhausted through the rotating shaft exhaust path 3.

[0035] On the other hand, in the second processing region S2, the second processing gas (O3 gas) supplied from the second gas nozzle 32 spreads in the second processing region S2 and flows toward the second exhaust port 72 provided near the rotation center of the turntable 2. As shown by the dashed line in Figs. 5 and 6, the flow of the O3 gas, which is the second processing gas, flows into the second exhaust port 72 through the gap 52 and the central gap 53 in the central region C. In this way, the O3 gas that has flowed into the central gap 53 from the second processing region S2 side is discharged to the second exhaust port 72. The O3 gas is guided upward in the space formed by the plate-like body 633 and the wall portion 631 of the partition plate 63, flows toward the ceiling surface side exhaust path 6, and is exhausted through the ceiling surface side exhaust path 6.

[0036] In the separation regions D1 and D2, the separation gas (N2 gas) supplied from the separation gas nozzles 33 and 34 spreads in the separation gas gap 44 and flows toward the first exhaust port 71 and the second exhaust port 72. As shown by the broken lines in Figs. 5 and 6, the flow of the N2 gas, which is the separation gas, flows from the separation gas gap 44 through the gap 52 into the central gap 53. Then, as shown in Fig. 6, a part of the N2 gas enters the gap 33 between the rotating shaft exhaust path 3 and the ceiling surface side exhaust path 6 in the central gap 53. The remaining N2 gas also flows toward the first exhaust port 71 and the second exhaust port 72. In this way, the N2 gas discharged to the first exhaust port 71 flows toward the rotating shaft exhaust path 3 like the DCS gas, and the N2 gas discharged to the second exhaust port 72 flows toward the ceiling surface side exhaust path 6 like the O3 gas.

[0037] As described above, the separation regions D1 and D2 are provided between the first processing region S1 and the second processing region S2 so as to separate the atmospheres of these processing regions S1 and S2. Therefore, even if DCS gas attempts to flow toward the second exhaust port 72 through the central gap 53, this flow is blocked by the flow of N2 gas, and the intrusion of DCS gas into the second exhaust port 72 is suppressed. On the other hand, even if O3 gas attempts to flow toward the first exhaust port 71 through the central gap 53, this flow is blocked by the flow of N2 gas, and the intrusion of O3 gas into the first exhaust port 71 is suppressed.

[0038] Returning to the explanation of the film forming process of the wafer W, the wafer W passes through the first processing region S1, and in the first processing region S1, the DCS gas, which is the first processing gas, is adsorbed to the wafer W while spreading radially on the turntable 2. Then, the wafer W to which the DCS gas is adsorbed passes through the second processing region S2 by the rotation of the turntable 2. In the second processing region S2, O3 gas, which is the second processing gas, is supplied, and the DCS gas adsorbed on the wafer W is oxidized by the O3 gas, and a thin film of silicon oxide film (SiO2 film) is formed on the surface of the wafer W. At this time, the O3 gas may be activated by using the activation mechanism described above as necessary.

[0039] By continuing to rotate the turntable 2 in this manner, the six revolving wafers W pass alternately between the first processing region S1 and the second processing region S2 repeatedly. Then, the adsorption of DCS gas onto the surface of the wafer W and the oxidation of the components of the adsorbed DCS gas are repeated many times in this order, and the reaction products are deposited to form a SiO2 film having a set thickness.

[0040] When the SiO2 film having the set thickness is formed and the film forming processing period ends, the wafer W is loaded / unloaded through the loading / unloading port 13. When the wafer W is unloaded, the recess 22 where the transfer takes place moves sequentially to the loading / unloading position facing the loading / unloading port 13 by the rotation of the turntable 2. Then, as described above, the wafer W is transferred between the external transfer arm and the transfer mechanism, unloaded from the loading / unloading port 13, and the next wafer W to be processed is loaded.

[0041] The present disclosure provides an improved exhaust structure for the vacuum vessel 10, but here, a brief description will be given of problems with the conventional exhaust structure. In an apparatus that revolves the wafer W by rotating a turntable and forms a film by the ALD method using a first process gas and a second process gas, an exhaust port is formed outside the wafer placement area in order to reduce particles. The layout of the exhaust port may be configured to be located outside the turntable or at the center of the turntable.

[0042] However, in a configuration in which the exhaust port is located outside the turntable, there is a risk that unreacted processing gas will flow around to the back side of the turntable, and there is a concern that components generated by thermal decomposition will be adsorbed onto the inner wall of the turntable or the vacuum vessel. On the other hand, in a configuration in which the exhaust port is located at the center of the turntable, the installation space for the exhaust path is limited at the center of the turntable. This may result in a decrease in the separation performance of the first processing gas and the second processing gas. In addition, by providing exhaust paths for two types of processing gas at the center of the turntable, the cross-sectional area of ​​the exhaust path is reduced. As a result, there is a concern that the pressure loss will increase and the exhaust speed will decrease.

[0043] In contrast, in the above-mentioned embodiment, when the first process gas and the second process gas are exhausted from the vicinity of the rotation center of the turntable 2 through different exhaust paths, it is possible to suppress a decrease in gas separation performance and a decrease in exhaust speed. In the above-mentioned embodiment, the rotary shaft exhaust path 3 is provided at the rotation center of the turntable 2, and the ceiling surface side exhaust path 6 is provided in the central area C of the top plate 11 of the vacuum vessel 10, so that the atmosphere in the vacuum vessel 10 is exhausted from the vicinity of the rotation center. Then, the first exhaust port 71 and the second exhaust port 72 are provided near the rotation center, and the first process gas is exhausted to the rotary shaft exhaust path 3 through the first exhaust port 71, and the second process gas is exhausted to the ceiling surface side exhaust path 6 through the second exhaust port 72.

[0044] In this manner, the configuration of the present disclosure has exhaust ports 71, 72 disposed near the center of the turntable 2, thereby solving the problems that would occur if exhaust ports were disposed outside the turntable 2. Also, dedicated exhaust ports 71, 72, rotating shaft exhaust path 3, and ceiling surface side exhaust path 6 are provided for the first process gas and the second process gas, respectively, and these rotating shaft exhaust path 3 and ceiling surface side exhaust path 6 are arranged in line in the vertical direction. This solves the problems that would occur if exhaust ports were disposed at the center of the turntable 2.

[0045] In other words, since the two exhaust paths are arranged vertically, a sufficient seal length can be ensured compared to when the two exhaust paths are arranged side by side. This makes it possible to suppress a decrease in gas separation performance, and the first process gas and the second process gas can be exhausted while maintaining high separation performance. Furthermore, by arranging the rotating shaft exhaust passage 3 and the ceiling surface side exhaust passage 6 above and below, the two exhaust passages 3, 6 overlap when viewed from above. This allows for space saving in the installation area of ​​the exhaust passages, so that the flow path cross-sectional area of ​​the exhaust passage can be designed to be larger than when two exhaust passages are arranged side by side in the left-right direction, ensuring a high exhaust speed.

[0046] Furthermore, in the above-described embodiment, the rotation axis of the turntable 2 is used as an exhaust path, and the turntable 2 rotates around the ceiling surface side exhaust path 6 fixed to the top plate 11 of the vacuum vessel 10. Therefore, the size and complexity of the device can be suppressed compared to the case where an exhaust path is provided separately from the rotation axis of the turntable 2.

[0047] Furthermore, in the above-mentioned embodiment, the protruding portion 61 is connected to the ceiling surface side exhaust path 6, and the partition plate 63 in the protruding portion 61 guides the first process gas to the rotating shaft exhaust path 3 and guides the second process gas to the ceiling surface side exhaust path 6. Therefore, due to the action of the partition plate 63 in the protruding portion 61, the first process gas and the second process gas are separated into the rotating shaft exhaust path 3 and the ceiling surface side exhaust path 6, respectively, and flow through them quickly. Therefore, the first process gas and the second process gas are prevented from accumulating in the protruding portion 61 and the central gap 53 and from being partially mixed.

[0048] Furthermore, the separation gas is introduced from the separation gas gap 44 into the central gap 53 where the first exhaust port 71 and the second exhaust port 72 are respectively opened, thereby preventing the second process gas from entering the first exhaust port 71 and the first process gas from entering the second exhaust port 72. Therefore, the first process gas and the second process gas can be exhausted through the rotating shaft exhaust path 3 and the ceiling surface side exhaust path 6 in a state where they are separated from each other, and mixing of the first process gas and the second process gas inside these exhaust paths 3 and 6 is prevented. As a result, the adhesion of reaction products of both process gases to each path 3 and 6 can be prevented.

[0049] <Second embodiment of the film forming apparatus> In the above, the configuration of the present disclosure is also applicable to the film forming apparatus shown in FIG. 7. FIG. 7 is a plan view showing a film forming apparatus 1A of the second embodiment. The film forming apparatus 1A is different from the film forming apparatus 1 shown in FIG. 2 and the like in the arrangement direction of the first gas nozzle 81 and the second gas nozzle 82. In this example, the first and second gas nozzles 81 and 82 made of tubular bodies are arranged so as to extend horizontally along the direction of a chord of a sector including the rotation center of the turntable 2. For example, the first gas nozzle 81 is arranged so as to extend horizontally along the direction of the chord of the sector between the downstream sides of the separation regions D1 and D2 in the rotation direction of the turntable. In addition, the second gas nozzle 82 is arranged so as to extend horizontally along the direction of the chord of the sector between the upstream sides of the rotation direction of the separation regions D1 and D2, for example, so as to face the first gas nozzle 81 across the rotation center.

[0050] The first and second gas nozzles 81, 82 are provided with a plurality of gas outlets 811, 812 on the side of the tube. For example, the gas outlets 811, 812 are provided so as to respectively discharge the first process gas and the second process gas toward the first exhaust port 71 and the second exhaust port 72. Except for the different arrangement of the first gas nozzle 81 and the second gas nozzle 82, the components of the separation regions D1, D2, the rotating shaft exhaust path 3, the ceiling surface side exhaust path 6, etc. are configured in the same manner as the film forming apparatus 1 of the first embodiment. Here, the same reference numerals are used for the same components of the film forming apparatus 1A as those of the film forming apparatus 1, and the description thereof will be omitted.

[0051] In this film forming apparatus 1A as well, the first process gas discharged from the first gas nozzle 81 spreads within the first process region S1, flows toward the first exhaust port 71, and is exhausted from the rotary shaft exhaust path 3 via the first exhaust port 71. The second process gas discharged from the second gas nozzle 82 spreads within the second process region S2, flows toward the second exhaust port 72, and is exhausted from the ceiling surface side exhaust path 6 via the second exhaust port 72.

[0052] Similar to the first embodiment, the flow of the separation gas prevents the first processing gas from entering the second processing region S2 and the second exhaust port 72, and prevents the second processing gas from entering the first processing region S1 and the first exhaust port 71. The exhaust structure including the rotating shaft exhaust path 3 and the ceiling surface side exhaust path 6 is also similar to the first embodiment, and therefore the same effects as the first embodiment can be obtained.

[0053] <Third embodiment> The film forming apparatus of the present disclosure may be configured as shown in FIG. 8. FIG. 8 is a vertical side view showing a part of the film forming apparatus 1B of the third embodiment. The rotating shaft exhaust passage 91 is made of a cylindrical body with a closed upper end, and the upper end is provided so as to protrude upward from the upper surface of the core part 21. A plurality of first exhaust ports 92 are formed at intervals from each other along the circumferential direction on the side surface of the upper end of the rotating shaft exhaust passage 91. The ceiling surface side exhaust passage 93 in this example is made of a cylindrical body with a closed lower end, and is arranged vertically with the centers aligned with respect to the rotating shaft exhaust passage 91. The lower end of the ceiling surface side exhaust passage 93 is located above the upper end of the rotating shaft exhaust passage 91, and a central gap 94 is formed between them. Therefore, the lower end of the ceiling surface side exhaust passage 93 forms a part of the central ceiling surface 95.

[0054] In the central region C1 of the top plate 11A, a first communication passage 96 is formed at a position corresponding to the first processing region S1, which guides the first processing gas that has passed through the processing region S1 toward the rotating shaft exhaust path 91. The first communication passage 96 is formed, for example, at the same height position so as to communicate with the first exhaust port 92 of the rotating shaft exhaust path 91. The first processing gas flows through the first communication passage 96 and is exhausted to the rotating shaft exhaust path 91 via the first exhaust port 92.

[0055] Furthermore, in the central region C1, at a position corresponding to the second processing region S2, a second communication passage 97 is formed to guide the second processing gas that has passed through the second processing region S2 toward the ceiling surface side exhaust path 93. Furthermore, a second exhaust port 98 communicating with the second communication passage 97 is formed in the ceiling surface side exhaust path 93. The second processing gas flows through the second communication passage 97 to the second exhaust port 98 and is exhausted to the ceiling surface side exhaust path 93.

[0056] The rotary table 2 and the separation regions D1 and D2 are configured similarly to the first embodiment, and the first gas nozzle and the second gas nozzle may be configured as in the first embodiment or the second embodiment. The other components of the film forming apparatus 1B are configured similarly to the first embodiment. In this embodiment, the rotary shaft exhaust passage 91 for exhausting the first process gas and the ceiling surface side exhaust passage 93 for exhausting the second process gas are arranged vertically, so that high gas separation performance and high exhaust speed can be ensured.

[0057] In the above-mentioned first to third embodiments, the first process gas is exhausted through the rotary shaft exhaust path, and the second process gas is exhausted through the ceiling surface side exhaust path. However, the present invention is not limited to this example, and the first process gas may be exhausted through the ceiling surface side exhaust path via the first exhaust port, and the second process gas may be exhausted through the rotary shaft exhaust path via the second exhaust port.

[0058] In the film forming apparatus of the present disclosure, the first process gas is not limited to DCS gas, and may be a gas containing silicon, such as bis(tertial butyl amino silane (BTBAS) gas. The second process gas is not limited to O3 gas, and may be another oxidizing gas. Furthermore, the present disclosure may be applied to a film forming apparatus that forms a silicon nitride (SiN) film on a wafer W by using a silicon-containing gas, such as DCS gas, as the first process gas and a nitriding gas, such as ammonia (NH3) gas, as the second process gas. In addition, the exhaust structure using the rotary shaft exhaust path and the ceiling surface side exhaust path of the present disclosure may be applied to a film forming apparatus that forms various films by the reaction between a first process gas and a second process gas, not limited to the above example.

[0059] In the above, the supply of the first process gas to the first process region and the supply of the second process gas to the second process region are not limited to the example performed using a gas nozzle made of a tube. For example, a gas supply unit having a plurality of gas outlets may be provided on the lower surface of the top plate 11 of the vacuum vessel 10 in the regions corresponding to the first process region S1 and the second process region S2, and the first and second process gases may be supplied in a shower-like manner.

[0060] Furthermore, the separation region is not limited to the above-mentioned configuration, but may have any structure including a separation gas supply section for supplying a separation gas, and main ceiling surfaces located on both sides of the separation gas supply section in the rotation direction for forming a separation gas gap between the rotation table. Therefore, the separation region is not limited to a configuration in which the convex portions 41 and 42 are formed, and for example, a separation gas supply chamber having an outlet for supplying a separation gas may be provided on the underside of the top plate, and the underside of the separation gas supply chamber may be used as the main ceiling surface.

[0061] Further, in the third embodiment, another example of the central region having the rotating shaft exhaust path, the ceiling surface side exhaust path, and the central ceiling surface is shown, but these configurations are not limited to the above-mentioned embodiment. Also, in the first and second embodiments, the protruding part provided in the ceiling surface side exhaust path may be a part of the cylindrical body constituting the ceiling surface side exhaust path, or may be constituted by another cylindrical body and connected to the ceiling surface side exhaust path. Furthermore, the shape of the protruding part and the partition plate is not limited to the above-mentioned configuration as long as the partition plate guides the first process gas to one of the rotating shaft exhaust path and the ceiling surface side exhaust path, and guides the second process gas to the other of the rotating shaft exhaust path and the ceiling surface side exhaust path.

[0062] In addition, depending on the types of the first and second process gases, the film formation process conditions such as the settings of the exhaust speed and film formation speed, the positions and sizes of the first and second process regions, and the positions of the first and second exhaust ports, there is a concern that the other process gas may unintentionally enter the rotating shaft exhaust path or the ceiling side exhaust path. In this way, when the inflow of some mixed gases causes problems such as film formation, the components of the exhaust paths of the rotating shaft exhaust path and the ceiling side exhaust path may be heated to suppress adhesion of reaction products to the inside of these exhaust paths.

[0063] The embodiments disclosed herein should be considered to be illustrative and not restrictive in all respects. The above-described embodiments may be omitted, substituted, or modified in various forms without departing from the scope and spirit of the appended claims. [Explanation of symbols]

[0064] 10 Vacuum container 2 Rotating table 3 Rotating shaft exhaust passage 33, 34 Separation gas nozzle 43 Main ceiling surface 44 Separation gas gap 53 Central Gap 54 Central ceiling surface 6 Ceiling side exhaust duct 71 First exhaust port 72 Second exhaust port C central area D1, D2 separation area W Semiconductor wafer

Claims

1. An apparatus for performing a film formation process on a substrate, comprising: a rotary table that is provided in a vacuum chamber, on one side of which the plurality of substrates are placed, and that rotates about a rotation center to revolve the plurality of substrates around the rotation center; a separation region including a separation gas supply unit for supplying a separation gas, the separation gas supply unit being provided between a first processing region to which a first processing gas that adsorbs to the substrate is supplied and a second processing region to which a second processing gas that reacts with the first processing gas to form a thin film on the surface of the substrate is supplied in order to separate the atmospheres of these processing regions in the rotation direction, and main ceiling surfaces being provided on both sides of the separation gas supply unit in the rotation direction and for forming a separation gas gap between the separation gas supply unit and the rotary table through which the separation gas flows; a central region having a central ceiling surface around the rotation center, the central ceiling surface forming a central gap between the rotation table and the central ceiling surface and communicating with the separation gas gap, in order to separate atmospheres of the first processing region and the second processing region; a rotary shaft exhaust passage including a cylindrical body connected to the rotary table for rotating the rotary table around the rotation center and having an exhaust passage formed therein; A ceiling surface side exhaust passage formed so as to vertically penetrate the member constituting the central region; an exhaust path on one side, which is the exhaust path on the rotating shaft or the exhaust path on the ceiling surface side, and a second exhaust path on the other side, which is the exhaust path on the rotating shaft or the exhaust path on the ceiling surface side, and a second exhaust path on the other side, which is different from the exhaust path on the one side.

2. An opening is formed at an upper end of the rotary shaft exhaust passage; a protruding portion formed of a cylindrical body protruding downward from the central ceiling surface and having a lower end inserted into an opening of the rotating shaft exhaust passage and having a communication port communicating with the inside of the rotating shaft exhaust passage, is connected to the ceiling surface side exhaust passage; 2. The apparatus of claim 1, wherein the first exhaust port and the second exhaust port are formed on a side surface of the protrusion located above the lower end inserted into the opening, and the protrusion is provided with a partition plate that divides the internal space of the protrusion so as to guide the first process gas exhausted from the first exhaust port to the exhaust path on one side and guide the second process gas exhausted from the second exhaust port to the exhaust path on the other side.

3. The apparatus of claim 2, wherein the first exhaust port discharges the first processing gas that flows into the central gap from the first processing region side, and the second exhaust port discharges the second processing gas that flows into the central gap from the second processing region side.

4. The apparatus of claim 3 , wherein the separation gas is caused to flow from the separation gas gap into the central gap to suppress ingress of the second process gas into the first exhaust port and ingress of the first process gas into the second exhaust port.

5. 5. The apparatus according to claim 1, further comprising: a first gas nozzle for supplying the first process gas to the first process region; and a second gas nozzle for supplying the second process gas to the second process region, the gas nozzles being arranged to extend horizontally along a radial direction of the turntable and configured as a tube having a plurality of gas outlets formed on a side surface thereof.

6. 5. The apparatus according to claim 1, comprising: a first gas nozzle for supplying the first process gas to the first process region; and a second gas nozzle for supplying the second process gas to the second process region, the gas nozzles being arranged to extend horizontally along a chord of a sector including the center of rotation of the turntable, and configured as a tube having a plurality of gas outlets formed on a side surface thereof.

7. A method for exhausting a process gas from an apparatus for performing a film formation process on a substrate, comprising the steps of: The apparatus for performing the film formation process includes: a rotary table that is provided in a vacuum chamber, on one side of which the plurality of substrates are placed, and that rotates about a rotation center to revolve the plurality of substrates around the rotation center; a separation region including a separation gas supply unit for supplying a separation gas, the separation gas supply unit being provided between a first processing region to which a first processing gas that adsorbs to the substrate is supplied and a second processing region to which a second processing gas that reacts with the first processing gas to form a thin film on the surface of the substrate is supplied in order to separate the atmospheres of these processing regions in the rotation direction, and main ceiling surfaces being provided on both sides of the separation gas supply unit in the rotation direction and for forming a separation gas gap between the separation gas supply unit and the rotary table through which the separation gas flows; a central region having a central ceiling surface around the rotation center, the central ceiling surface forming a central gap between the rotation table and the central ceiling surface and communicating with the separation gas gap, in order to separate atmospheres of the first processing region and the second processing region; a rotary shaft exhaust passage including a cylindrical body connected to the rotary table for rotating the rotary table around the rotation center and having an exhaust passage formed therein; a ceiling surface side exhaust passage formed so as to vertically penetrate a member constituting the central region, a step of exhausting the first process gas discharged from the first process region to one exhaust path, which is the rotating shaft exhaust path or the ceiling surface side exhaust path; and a step of exhausting the second process gas discharged from the second process region to the other exhaust path, which is the rotating shaft exhaust path or the ceiling surface side exhaust path and is different from the one exhaust path.

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