Film forming apparatus and determination method

Abstract

A technique is provided that can improve the accuracy of determining the timing of cleaning processing. [Solution] A film forming apparatus according to one aspect of the present disclosure is a film forming apparatus that performs a film forming process to form a film within a vacuum container and a cleaning process to remove the film formed within the vacuum container, and includes a vacuum container, a component placed within the vacuum container, an acquisition unit that acquires first information regarding electromagnetic waves transmitted through or reflected by the component, and a control circuit, and the control circuit determines at least one of the start timing and end timing of the cleaning process based on the first information acquired by the acquisition unit.

Description

[Technical Field]

[0001] The present disclosure relates to a film forming apparatus and a determination method. [Background technology]

[0002] Patent Document 1 discloses detecting the end point of a cleaning process based on an image captured of a low-temperature surface inside a vacuum chamber. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Patent Publication No. 2021-128977 Summary of the Invention [Problem to be solved by the invention]

[0004] The present disclosure provides a technique that can improve the accuracy of determining the timing of the cleaning process. [Means for solving the problem]

[0005] A film forming apparatus according to one embodiment of the present disclosure is a film forming apparatus that performs a film forming process to form a film within a vacuum container and a cleaning process to remove the film formed within the vacuum container, and includes a vacuum container, a component placed within the vacuum container, an acquisition unit that acquires first information regarding electromagnetic waves transmitted through or reflected by the component, and a control circuit, and the control circuit determines at least one of the start timing and end timing of the cleaning process based on the first information acquired by the acquisition unit. [Effects of the Invention]

[0006] According to the present disclosure, it is possible to improve the accuracy of determining the timing of the cleaning process. [Brief explanation of the drawings]

[0007] [Figure 1]1 is a cross-sectional view showing an example of the configuration of a film forming apparatus according to an embodiment. [Figure 2] FIG. 2 is a perspective view showing the configuration inside a vacuum chamber of the film forming apparatus according to the embodiment. [Figure 3] FIG. 2 is a plan view showing the configuration inside a vacuum chamber of the film forming apparatus according to the embodiment. [Figure 4] FIG. 2 is a cross-sectional view showing a part of the film forming apparatus according to the embodiment. [Figure 5] FIG. 4 is a cross-sectional view showing another part of the film forming apparatus according to the embodiment. [Figure 6] 4 is a flowchart illustrating a determination method according to a first example of an embodiment. [Figure 7] FIG. 1 is a cross-sectional view (1) showing a determination method according to a first example of an embodiment. [Figure 8] FIG. 10 is a cross-sectional view (2) showing the determination method according to the first example of the embodiment. [Figure 9] FIG. 10 is a cross-sectional view (3) showing the determination method according to the first example of the embodiment. [Figure 10] FIG. 4 is a cross-sectional view (4) showing the determination method according to the first example of the embodiment. [Figure 11] FIG. 5 is a cross-sectional view (5) showing a determination method according to the first example of the embodiment. [Figure 12] 10 is a flowchart illustrating a determination method according to a second example of the embodiment. [Figure 13] 10 is a flowchart illustrating a determination method according to a third example of the embodiment. [Figure 14] FIG. 10 is a cross-sectional view (1) showing a determination method according to a third example of the embodiment. [Figure 15] FIG. 10 is a cross-sectional view (2) showing a determination method according to a third example of the embodiment. [Figure 16] FIG. 10 is a cross-sectional view (3) showing a determination method according to a third example of the embodiment. [Figure 17] FIG. 4 is a cross-sectional view (4) showing a determination method according to a third example of the embodiment. [Figure 18] FIG. 5 is a cross-sectional view (5) showing a determination method according to a third example of the embodiment. [Figure 19] FIG. 6 is a cross-sectional view (6) showing a determination method according to a third example of the embodiment. [Figure 20] 10 is a flowchart illustrating a determination method according to a fourth example of the embodiment. DETAILED DESCRIPTION OF THE INVENTION

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

[0009] [Film forming equipment] A film formation apparatus 100 according to an embodiment will be described with reference to FIGS. 1 to 5. FIG. 1 is a cross-sectional view showing an example of the configuration of the film formation apparatus 100 according to the embodiment. FIG. 2 is a perspective view showing the configuration inside a vacuum chamber 1 of the film formation apparatus 100 according to the embodiment. FIG. 3 is a plan view showing the configuration inside a vacuum chamber 1 of the film formation apparatus 100 according to the embodiment. The top plate 11 is not shown in FIGS. 2 and 3. FIG. 4 is a cross-sectional view showing a part of the film formation apparatus 100 according to the embodiment. FIG. 5 is a cross-sectional view showing another part of the film formation apparatus 100 according to the embodiment.

[0010] As shown in FIGS. 1 to 3, the film forming apparatus 100 includes a vacuum chamber 1 and a susceptor 2.

[0011] The vacuum vessel 1 has a substantially circular planar shape. The vacuum vessel 1 has a top plate 11 and a vessel body 12. The top plate 11 is airtightly and detachably arranged on the upper surface of the vessel body 12 via a sealing member 13 such as an O-ring. A window 11a is provided in a part of the top plate 11. The window 11a is made of, for example, quartz. The window 11a is configured so that the susceptor 2 inside the vacuum vessel 1 can be seen from the outside. The vessel body 12 has a cylindrical shape with a bottom.

[0012] The susceptor 2 is provided within the vacuum vessel 1. The susceptor 2 has a rotation center at the center of the vacuum vessel 1. The susceptor 2 is made of, for example, quartz. The susceptor 2 is fixed at its center to a cylindrical core portion 21. The core portion 21 is fixed to the upper end of a rotation shaft 22. The rotation shaft 22 extends vertically. The rotation shaft 22 penetrates the bottom portion 14 of the vacuum vessel 1. The lower end of the rotation shaft 22 is attached to a drive unit 23. The drive unit 23 rotates the rotation shaft 22 around the vertical axis. The rotation shaft 22 and the drive unit 23 are housed in a case body 20. The case body 20 has a cylindrical shape with an open top. A flange portion provided on the top surface of the case body 20 is airtightly attached to the lower surface of the bottom portion 14 of the vacuum vessel 1. This maintains an airtight state between the internal atmosphere of the case body 20 and the external atmosphere.

[0013] A plurality of (e.g., six) recesses 24 are formed on the upper surface of the susceptor 2 along the rotation direction (circumferential direction). Each recess 24 has a circular shape. A substrate W is placed in each recess 24. The substrate W is, for example, a semiconductor wafer. For convenience, FIG. 3 shows only one recess 24 for the substrate W. Each recess 24 is provided at a position horizontally offset from the rotation axis 22 of the susceptor 2. Each recess 24 has an inner diameter that is slightly larger than the diameter of the substrate W, for example, by 4 mm, and a depth that is approximately equal to the thickness of the substrate W. Therefore, when the substrate W is placed in the recess 24, the surface of the substrate W and the surface of the susceptor 2 (the area where the substrate W is not placed) are flush with each other. A through-hole (not shown) is formed in the bottom surface of the recess 24. A plurality of (e.g., three) lift pins pass through the through-hole to support the back surface of the substrate W and lift the substrate W.

[0014] Above the susceptor 2, process gas nozzles 31 and 32, a cleaning gas nozzle 33, and separation gas nozzles 41 and 42 are arranged at intervals from one another in the circumferential direction of the vacuum chamber 1 (the rotation direction of the susceptor 2 indicated by arrow A in FIG. 3). In the illustrated example, the separation gas nozzle 41, cleaning gas nozzle 33, process gas nozzle 31, separation gas nozzle 42, and process gas nozzle 32 are arranged in this order clockwise (the rotation direction of the susceptor 2) from a transfer port 15 described below. Gas inlet ports 31a, 32a, 33a, 41a, and 42a (FIG. 3), which are the base ends of the process gas nozzles 31 and 32, the cleaning gas nozzle 33, and the separation gas nozzles 41 and 42, are fixed to the outer peripheral wall of the chamber body 12. The process gas nozzles 31, 32, cleaning gas nozzle 33, and separation gas nozzles 41, 42 are introduced into the vacuum vessel 1 from the outer peripheral wall of the vacuum vessel 1 and attached so as to extend horizontally relative to the susceptor 2 along the radial direction of the vessel body 12. The process gas nozzles 31, 32, cleaning gas nozzle 33, and separation gas nozzles 41, 42 are made of, for example, quartz.

[0015] The process gas nozzle 31 is connected to a source gas supply source (not shown) via a pipe and a flow rate controller (not shown). The source gas is, for example, a silicon-containing gas. The source gas may also be a metal-containing gas.

[0016] The process gas nozzle 32 is connected to a reactive gas supply source (not shown) via piping and a flow controller (not shown). The reactive gas is a gas that reacts with the source gas to produce a reaction product. The reactive gas is, for example, an oxidizing gas. The reactive gas may also be a nitriding gas.

[0017] The cleaning gas nozzle 33 is connected to a cleaning gas supply source (not shown) via piping and a flow rate controller (not shown). The cleaning gas is a gas that can remove reaction products generated by the reaction between the source gas and the reactive gas. The cleaning gas is selected depending on the types of the source gas and the reactive gas. The cleaning gas may be a halogen-containing gas. The cleaning gas may be a fluorine-containing gas such as chlorine trifluoride (ClF3) or nitrogen trifluoride (NF3). The cleaning gas may also be a chlorine-containing gas, a bromine-containing gas, or an iodine-containing gas.

[0018] The separation gas nozzles 41 and 42 are both connected to a separation gas supply source (not shown) via piping and flow control valves (not shown). The separation gas may be an inert gas. For example, the separation gas is argon (Ar). The separation gas may also be nitrogen (N).

[0019] The process gas nozzles 31, 32 have a plurality of discharge holes 31h, 32h (FIG. 4) that open toward the susceptor 2 and are arranged at intervals of, for example, 10 mm along the longitudinal direction of the process gas nozzles 31, 32. The region below the process gas nozzle 31 serves as an adsorption region P1 for adsorbing the source gas onto the substrate W. The region below the process gas nozzle 32 serves as a reaction region P2 for reacting the source gas adsorbed onto the substrate W in the adsorption region P1 with a reactive gas.

[0020] As shown in Figures 2 and 3, two convex portions 4 are provided inside the vacuum vessel 1. The convex portions 4, together with separation gas nozzles 41 and 42, form a separation region D. For this reason, as will be described later, they are attached to the rear surface of the top plate 11 so as to protrude toward the susceptor 2. The convex portions 4 have a fan-shaped planar shape with an arc-shaped top. The convex portions 4 are arranged so that their inner arcs are connected to the protruding portions 5 (described later) and their outer arcs are aligned along the inner circumferential surface of the vessel body 12 of the vacuum vessel 1.

[0021] FIG. 4 shows a cross section of the vacuum chamber 1 along the concentric circle of the susceptor 2 from the process gas nozzle 31 to the process gas nozzle 32. As shown in FIG. 4, a convex portion 4 is attached to the rear surface of the top plate 11. Therefore, within the vacuum chamber 1, there is a flat, low ceiling surface (first ceiling surface 44) that is the underside of the convex portion 4, and ceiling surfaces (second ceiling surfaces 45) that are higher than the first ceiling surface 44 and are located on both circumferential sides of the first ceiling surface 44. The first ceiling surface 44 has a fan-shaped planar shape with its top cut into an arc. A groove portion 43 is formed in the circumferential center of the convex portion 4, extending radially. A separation gas nozzle 42 is housed in the groove portion 43. A similar groove portion 43 is also formed in the other convex portion 4, and a separation gas nozzle 41 is housed in the groove portion 43. The process gas nozzles 31 and 32 are respectively provided in the space below the second ceiling surface 45. The processing gas nozzles 31 and 32 are provided near the substrate W and spaced apart from the second ceiling surface 45. As shown in Fig. 4, the processing gas nozzle 31 is provided in a space 481 below the second ceiling surface 45 on the right side of the convex portion 4, and the processing gas nozzle 32 is provided in a space 482 below the second ceiling surface 45 on the left side.

[0022] The separation gas nozzle 42 is provided with a plurality of discharge holes 42h that open toward the susceptor 2. The plurality of discharge holes 42h are arranged at intervals of, for example, 10 mm along the longitudinal direction of the separation gas nozzle 42. The separation gas nozzle 41 also has a plurality of discharge holes (not shown) arranged therein, similar to the separation gas nozzle 42.

[0023] The first ceiling surface 44 forms a narrow separation space H relative to the susceptor 2. When separation gas is supplied from the discharge holes 42h of the separation gas nozzle 42, the separation gas flows through the separation space H toward the spaces 481 and 482. At this time, because the volume of the separation space H is smaller than the volumes of the spaces 481 and 482, the separation gas can increase the pressure in the separation space H compared to the pressure in the spaces 481 and 482. In other words, a high-pressure separation space H is formed between the spaces 481 and 482. The separation gas flowing from the separation space H to the spaces 481 and 482 acts as a counterflow to the source gas from the adsorption region P1 and the reactant gas from the reaction region P2. Therefore, the source gas supplied to the adsorption region P1 and the reactant gas supplied to the reaction region P2 are separated by the separation space H. This reduces the reaction between the source gas and the reactant gas that occurs due to mixing of the two gases in the vacuum chamber 1.

[0024] The height h1 of the first ceiling surface 44 relative to the upper surface of the susceptor 2 is set to a height suitable for making the pressure in the separation space H higher than the pressure in the spaces 481 and 482, taking into consideration the pressure inside the vacuum chamber 1 during film formation, the rotation speed of the susceptor 2, the flow rate of the separation gas, etc.

[0025] A protrusion 5 is provided on the underside of the top plate 11, surrounding the outer periphery of the core portion 21 that fixes the susceptor 2. The protrusion 5 is continuous with the part of the convex portion 4 on the side of the rotation center, and its underside is formed at the same height as the first ceiling surface 44.

[0026] FIG. 1, previously referred to, is a cross-sectional view taken along line I-I' in FIG. 3 and shows the region where the second ceiling surface 45 is provided. Meanwhile, FIG. 5 shows the region where the first ceiling surface 44 is provided. As shown in FIG. 5, an L-shaped bent portion 46 is formed on the periphery of the fan-shaped convex portion 4 (the portion on the outer edge side of the vacuum vessel 1) so as to face the outer end surface of the susceptor 2. Similar to the convex portion 4, the bent portion 46 reduces the intrusion of source gas and reactant gas from both sides of the separation region D and reduces mixing of the source gas and reactant gas. The convex portion 4 is provided on the top plate 11, and since the top plate 11 is detachable from the vessel body 12, there is a slight gap between the outer peripheral surface of the bent portion 46 and the vessel body 12. The gap between the inner peripheral surface of the bent portion 46 and the outer end surface of the susceptor 2 and the gap between the outer peripheral surface of the bent portion 46 and the vessel body 12 are set to dimensions similar to the height of the first ceiling surface 44 relative to the top surface of the susceptor 2.

[0027] The inner peripheral wall of the vessel body 12 is formed as a vertical surface close to the outer peripheral surface of the bent portion 46 in the separation region D (FIG. 5). However, in areas other than the separation region D, it is recessed outward, for example, from the portion facing the outer end surface of the susceptor 2 to the bottom 14 (FIG. 1). Hereinafter, for convenience of explanation, the recessed portion having a generally rectangular cross section will be referred to as the exhaust region E. Specifically, the exhaust region communicating with the adsorption region P1 will be referred to as the first exhaust region E1, and the region communicating with the reaction region P2 will be referred to as the second exhaust region E2. As shown in FIGS. 1 to 3, a first exhaust port 61 and a second exhaust port 62 are formed at the bottom of the first exhaust region E1 and the second exhaust region E2, respectively. The first exhaust port 61 and the second exhaust port 62 are connected to a vacuum exhaust unit, such as a vacuum pump 64, via exhaust pipes 63, as shown in FIG. 1. A pressure controller 65 is provided in the exhaust pipe 63, allowing adjustment of the pressure inside the vacuum vessel 1.

[0028] 1 and 5, a heater unit 7 is provided in the space between the susceptor 2 and the bottom 14 of the vacuum chamber 1. The heater unit 7 heats the substrate W on the susceptor 2 to a temperature determined by a process recipe by radiation.

[0029] An annular cover member 71 is provided below the periphery of the susceptor 2 (FIG. 5). The cover member 71 separates the atmosphere from the space above the susceptor 2 to the first and second exhaust regions E1 and E2 from the atmosphere in which the heater unit 7 is located, thereby reducing the intrusion of gas into the region below the susceptor 2. The cover member 71 includes an inner member 71a and an outer member 71b. The inner member 71a faces the outer edge of the susceptor 2 and the area outside the outer edge from below. The inner member 71a surrounds the heater unit 7 along the entire periphery below the outer edge of the susceptor 2 (and below a portion slightly outside the outer edge). The outer member 71b is provided between the inner member 71a and the inner circumferential surface of the vacuum chamber 1. The outer member 71b is provided below and adjacent to the bent portion 46 formed at the outer edge of the convex portion 4 in the separation region D.

[0030] The bottom 14, located closer to the center of rotation than the space in which the heater unit 7 is disposed, protrudes upward to form a protrusion 12a, approaching the core 21 near the center of the underside of the susceptor 2. A narrow space is formed between the protrusion 12a and the core 21. The gap between the inner circumferential surface of the through-hole of the rotating shaft 22 penetrating the bottom 14 and the rotating shaft 22 is also narrow, and these narrow spaces communicate with the case body 20. A purge gas supply pipe 72 is provided in the case body 20. The purge gas supply pipe 72 supplies a purge gas into the narrow space to purge it. The purge gas is, for example, the same gas as the separation gas. A plurality of purge gas supply pipes 73 are provided in the bottom 14 of the vacuum vessel 1. The plurality of purge gas supply pipes 73 are provided below the heater unit 7 at predetermined angular intervals in the circumferential direction. The plurality of purge gas supply pipes 73 supply a purge gas into the space in which the heater unit 7 is disposed to purge it. A lid member 7a is provided between the heater unit 7 and the susceptor 2. The lid member 7a circumferentially covers the area from the inner peripheral wall of the outer member 71b (the upper surface of the inner member 71a) to the upper end of the protrusion 12a. This reduces the intrusion of gas into the area where the heater unit 7 is provided. The lid member 7a is made of, for example, quartz.

[0031] A separation gas supply pipe 51 is connected to the center of the top plate 11 of the vacuum chamber 1. The separation gas supply pipe 51 supplies separation gas to a space 52 between the top plate 11 and the core section 21. The separation gas supplied to the space 52 is discharged toward the periphery along the surface of the susceptor 2 on the wafer placement region side through a narrow gap 50 between the protrusion 5 and the susceptor 2. The gap 50 can be maintained at a higher pressure than the spaces 481 and 482 by the separation gas. The gap 50 reduces mixing of the source gas supplied to the adsorption region P1 and the reaction gas supplied to the reaction region P2 through the central region C. In other words, the gap 50 (or the central region C) functions similarly to the separation space H (or the separation region D).

[0032] 2 and 3, a transfer port 15 is provided in the side wall of the vacuum chamber 1 for transferring the substrate W between an external transfer arm 10 and the susceptor 2. The transfer port 15 is opened and closed by a gate valve (not shown). Below the susceptor 2, at a position corresponding to the transfer position of the substrate W, a transfer lift pin and its lift mechanism (neither of which is shown) are provided which penetrate the recess 24 and lift the substrate W from the backside.

[0033] The film forming apparatus 100 includes an imaging unit 8. The imaging unit 8 is provided above the window 11a. The imaging unit 8 is configured to be able to capture an image of the upper surface of the susceptor 2 through the window 11a. The imaging unit 8 may include a camera, and an image may be generated by the camera. In the example of FIG. 1, there is one imaging unit 8, but there may be two or more imaging units 8. The imaging unit 8 is an example of an acquisition unit.

[0034] The imaging unit 8 captures an image of the upper surface of the susceptor 2 before the film is formed, and acquires an image of the upper surface of the susceptor 2 before the film is formed (hereinafter referred to as a "comparison image"). The imaging unit 8 transmits the acquired comparison image to the control circuit 9. The comparison image is an example of first information. The susceptor 2 before the film 101 is formed is, for example, a brand new susceptor 2. The susceptor 2 before the film 101 is formed may also be a susceptor 2 in a state where the film on the upper surface has been removed by a cleaning process.

[0035] The imaging unit 8 captures an image of the upper surface of the susceptor 2 after the film formation process has been performed, and acquires an image of the upper surface of the susceptor 2 after the film formation process has been performed (hereinafter referred to as a "first determination image"). The imaging unit 8 transmits the acquired first determination image to the control circuit 9. The first determination image is an example of first information. The imaging unit 8 may acquire the first determination image while the film formation process is being performed.

[0036] The imaging unit 8 captures an image of the upper surface of the susceptor 2 during the cleaning process, and acquires an image of the upper surface of the susceptor 2 during the cleaning process (hereinafter referred to as a "second determination image"). The imaging unit 8 transmits the acquired second determination image to the control circuit 9. The second determination image is an example of first information.

[0037] The film forming apparatus 100 includes a control circuit 9. The control circuit 9 is an electronic circuit such as a central processing unit (CPU), a field programmable gate array (FPGA), or an application specific integrated circuit (ASIC). The control circuit 9 executes various control operations described in this specification by executing instruction codes stored in a memory or by being a circuit designed for a specific application.

[0038] The control circuit 9 controls each part of the film formation apparatus 100 to perform a film formation process and a cleaning process. The film formation process includes, for example, forming a film on a substrate W placed on the susceptor 2 (recess 24) in the vacuum chamber 1. In the film formation process, a film is formed not only on the surface of the substrate W but also on the susceptor 2. The susceptor 2 is an example of a component disposed in the vacuum chamber 1. As the thickness of the film formed on the susceptor 2 increases, the film peels off from the susceptor 2, generating particles. The particles adhere to the surface of the substrate W during the film formation process and contaminate the substrate W. The cleaning process includes, for example, removing a film formed on the susceptor 2 during the film formation process. The cleaning process is performed, for example, periodically. The cleaning process is performed, for example, before the film formed on the susceptor 2 peels off. This allows the film formed on the susceptor 2 to be removed before it peels off, preventing the generation of particles.

[0039] The cleaning process is performed by supplying a cleaning gas into the vacuum chamber 1 for a predetermined time. The predetermined time varies depending on changes in the operation of the film formation apparatus 100, etc. If the cleaning process time is too short, a film will remain on the susceptor 2, making it more likely that particles will be generated during the next film formation process. If the cleaning process time is too long, the susceptor 2 will be etched, reducing its strength and shortening its lifespan. For this reason, it is important to end the cleaning process at an appropriate time.

[0040] The control circuit 9 determines the timing of the end of the cleaning process based on the second judgment image and the comparison image acquired by the imaging unit 8. For example, the control circuit 9 calculates the difference between color information at a predetermined position in the second judgment image and color information at a predetermined position in the comparison image, and determines the timing of the end of the cleaning process based on the calculated difference. The predetermined position in the comparison image is, for example, the same as the predetermined position in the second judgment image. The color information is, for example, RGB values ​​(red, green, blue). The control circuit 9 may calculate the difference in intensity of at least one of the three primary colors (red, green, and blue) that make up the RGB values ​​of the second judgment image and the comparison image, and determine the timing of the end of the cleaning process based on the calculated difference. The color information may be HSL values ​​(hue, saturation, and lightness). The control circuit 9 controls the operation of each component of the film forming apparatus 100 so that the cleaning process ends at the determined end timing. This improves the accuracy of determining the timing of the end of the cleaning process.

[0041] For example, suppose the susceptor 2 is made of quartz and the film formed in the film formation process is a silicon film, and the blue intensities constituting the RGB values ​​at the predetermined positions of the second judgment image and the comparison image are 30 and 150, respectively. In this case, the control circuit 9 calculates a calculated value by subtracting the blue intensity at the predetermined position of the comparison image from the blue intensity at the predetermined position of the second judgment image. The calculated value is −120. The blue intensity at the predetermined position of the second judgment image increases as the thickness of the silicon film decreases. When the silicon film is completely removed, the blue intensity at the predetermined position of the second judgment image becomes equal to or greater than the blue intensity at the predetermined position of the comparison image. Therefore, by having the control circuit 9 determine to terminate the cleaning process when the calculated value is equal to or greater than 0, under-etching and over-etching can be reduced.

[0042] The control circuit 9 may determine the timing to start the cleaning process based on the first determination image and the comparison image acquired by the imaging unit 8. For example, the control circuit 9 calculates the difference between color information at a predetermined position in the first determination image and color information at a predetermined position in the comparison image, and determines the timing to start the cleaning process based on the calculated difference. The predetermined position in the comparison image is, for example, the same as the predetermined position in the first determination image. The color information may be, for example, RGB values ​​(red, green, blue). The control circuit 9 may calculate the difference in intensity of at least one of the three primary colors (red, green, and blue) that make up the RGB values ​​of the first determination image and the comparison image, and determine the timing to start the cleaning process based on the calculated difference. The color information may be HSL values ​​(hue, saturation, and lightness). The control circuit 9 controls the operation of each component of the film forming apparatus 100 so that the cleaning process starts at the determined start timing. This improves the accuracy of determining the start timing of the cleaning process.

[0043] [Judgment method] A determination method according to a first example of an embodiment will be described with reference to FIGS. 6 to 11. The determination method according to the first example of an embodiment is a method for determining the start and end timings of cleaning when a film formed on a substrate W during a film formation process is a colored film. Examples of colored films include silicon films, silicon nitride films, high-dielectric-constant (High-k) films, and titanium nitride films. The determination method according to the first example of an embodiment is performed under the control of a control circuit 9.

[0044] Fig. 6 is a flowchart showing a determination method according to a first example of the embodiment. Figs. 7 to 11 are cross-sectional views showing the determination method according to the first example of the embodiment. The determination method shown in Fig. 6 includes steps S11 to S21.

[0045] 7, in step S11, the imaging unit 8 captures an image of the upper surface of the susceptor 2 before the film 101 is formed, and obtains a comparative image of the susceptor 2. The imaging unit 8 transmits the obtained comparative image to the control circuit 9.

[0046] In step S12, the control circuit 9 controls each part of the film formation apparatus 100 to perform a film formation process. The film formation process is performed with the substrate W placed on the susceptor 2. When the film formation process is performed, a film 101 is also formed on the upper surface of the susceptor 2, as shown in FIG.

[0047] 8, in step S13, the imaging unit 8 captures an image of the upper surface of the susceptor 2 after the film formation process has been performed, and acquires a first determination image of the susceptor 2. The imaging unit 8 transmits the acquired first determination image to the control circuit 9. In step S13, the imaging unit 8 may acquire the first determination image during the execution of the film formation process in step S12.

[0048] In step S14, the control circuit 9 calculates the difference between the color information at a predetermined position in the first determination image and the color information at a predetermined position in the comparison image. The difference becomes larger as the thickness of the film 101 formed on the upper surface of the susceptor 2 increases.

[0049] In step S15, the control circuit 9 determines whether to start the cleaning process based on the calculated difference. For example, the control circuit 9 determines to start the cleaning process when the absolute value of the calculated difference exceeds a preset threshold. The threshold is set through a preliminary experiment or the like so that film peeling from the susceptor 2 does not occur. If it is determined in step S15 that the cleaning process should be started (YES in step S15), the control circuit 9 proceeds to step S16. If it is determined in step S15 that the cleaning process should not be started (NO in step S15), the control circuit 9 returns the process to step S12. That is, the control circuit 9 controls each part of the film forming apparatus 100 to repeatedly perform the film forming process without performing the cleaning process until it is determined in step S15 that the cleaning process should be started. When the film forming process is repeated, the thickness of the film 101 formed on the upper surface of the susceptor 2 increases, as shown in FIG. 9 .

[0050] In step S16, the control circuit 9 controls each part of the film forming apparatus 100 to start the cleaning process. When the cleaning process starts, the thickness of the film 101 formed on the upper surface of the susceptor 2 gradually decreases, as shown in FIG.

[0051] In step S17, the imaging unit 8 captures an image of the upper surface of the susceptor 2 during the cleaning process, and acquires a second determination image of the susceptor 2. The imaging unit 8 transmits the acquired second determination image to the control circuit 9.

[0052] In step S18, the control circuit 9 calculates the difference between the color information at a predetermined position in the second determination image and the color information at a predetermined position in the comparison image. The thinner the thickness of the film 101 formed on the upper surface of the susceptor 2, the smaller the value of the difference.

[0053] In step S19, the control circuit 9 determines whether or not to end the cleaning process based on the calculated difference. For example, when the absolute value of the calculated difference is equal to or less than a preset threshold, the control circuit 9 determines that the film 101 has been removed and determines to end the cleaning process. The threshold is, for example, 0 (zero). If it is determined to end the cleaning process in step S19 (YES in step S19), the control circuit 9 proceeds to step S20. If it is determined not to end the cleaning process in step S19 (NO in step S19), the control circuit 9 returns the process to step S17. That is, the control circuit 9 controls each part of the film forming apparatus 100 to continue the cleaning process until it is determined to end the cleaning process in step S19.

[0054] In step S20, the control circuit 9 controls each part of the film forming apparatus 100 to end the cleaning process, thereby removing the film 101 formed on the upper surface of the susceptor 2, as shown in FIG.

[0055] In step S21, the control circuit 9 determines whether or not to perform apparatus maintenance. Whether or not to perform apparatus maintenance is determined based on, for example, the number of times and duration of cleaning processing performed from the time when the susceptor 2 was replaced. If it is determined in step S21 that apparatus maintenance is to be performed (YES in step S21), the control circuit 9 ends the processing shown in Fig. 6. If it is determined in step S21 that apparatus maintenance is not to be performed (NO in step S21), the control circuit 9 returns the processing to step S12.

[0056] As described above, according to the determination method of the first example embodiment, the control circuit 9 calculates the difference between the color information at a predetermined position on the first determination image and the color information at a predetermined position on the comparison image, and determines the start timing of the cleaning process based on the calculated difference. In this case, the accuracy of determining the start timing of the cleaning process can be improved. Furthermore, the control circuit 9 calculates the difference between the color information at a predetermined position on the second determination image and the color information at a predetermined position on the comparison image, and determines the end timing of the cleaning process based on the calculated difference. In this case, the accuracy of determining the end timing of the cleaning process can be improved.

[0057] A determination method according to a second example of the embodiment will be described with reference to Fig. 12. The determination method according to the second example of the embodiment differs from the determination method according to the first example of the embodiment in that the imaging unit 8 acquires a new comparison image each time a cleaning process is performed. In other respects, the determination method may be the same as the determination method according to the first example of the embodiment. Fig. 12 is a flowchart showing the determination method according to the second example of the embodiment.

[0058] 12, in the determination method according to the second example of the embodiment, if it is determined in step S21 that apparatus maintenance will not be performed (NO in step S21), the control circuit 9 returns the process to step S11. That is, the image capturing unit 8 acquires a new comparison image, and the control circuit 9 determines whether or not to terminate the cleaning process based on the difference between the color information of the second determination image and the color information of the comparison image newly received from the image capturing unit 8. In this case, even if the surface condition of the susceptor 2 changes due to the cleaning process, the latest comparison image can be used, and therefore the timing to terminate the cleaning process can be determined with high accuracy.

[0059] 13 to 19, a determination method according to a third example of the embodiment will be described. The determination method according to the third example of the embodiment is a method for determining the start and end timings of cleaning when a film formed on a substrate W during a film formation process is a transparent film or a white film. The transparent film is, for example, a silicon oxide film. The determination method according to the third example of the embodiment is performed under the control of a control circuit 9.

[0060] Fig. 13 is a flowchart showing a determination method according to a third example of the embodiment. Figs. 14 to 19 are cross-sectional views showing the determination method according to the third example of the embodiment. The determination method shown in Fig. 13 includes steps S31 to S40.

[0061] 14, in step S31, the imaging unit 8 captures an image of the upper surface of the susceptor 2 before the film 101 is formed, and obtains a comparative image of the susceptor 2. The imaging unit 8 transmits the obtained comparative image to the control circuit 9.

[0062] 15, in step S32, the control circuit 9 controls each part of the film forming apparatus 100 to perform a color film process to form a color film 102 on the surface of the susceptor 2. The color film process is performed, for example, in a state where the substrate W is not placed on the susceptor 2. The color film 102 is, for example, a silicon film, a silicon nitride film, a high dielectric constant (High-k) film, or a titanium nitride film.

[0063] In step S33, the control circuit 9 controls each part of the film formation apparatus 100 to perform a film formation process. The film formation process is performed with the substrate W placed on the susceptor 2. When the film formation process is performed, a film 103 is also formed on the colored film 102, as shown in FIG.

[0064] In step S34, the control circuit 9 determines whether or not to start the cleaning process. Whether or not to start the cleaning process is determined based on, for example, the effective number of times the film formation process has been performed, the execution time, etc., from the time the cleaning process was performed. If it is determined in step S34 that the cleaning process should be started (YES in step S34), the control circuit 9 proceeds to step S35. If it is determined in step S34 that the cleaning process should not be started (NO in step S34), the control circuit 9 returns the process to step S32. That is, the control circuit 9 controls each part of the film formation apparatus 100 to repeatedly perform the film formation process without performing the cleaning process until it determines in step S34 that the cleaning process should be started. When the film formation process is repeated, the thickness of the film 103 formed on the colored film 102 increases, as shown in FIG. 17.

[0065] In step S35, the control circuit 9 controls each part of the film forming apparatus 100 to start the cleaning process. When the cleaning process starts, the thickness of the film 103 formed on the colored film 102 gradually decreases, as shown in FIG.

[0066] In step S36, the imaging unit 8 captures an image of the upper surface of the susceptor 2 during the cleaning process, and obtains a second determination image of the susceptor 2. The imaging unit 8 transmits the obtained second determination image to the control circuit 9.

[0067] In step S37, the control circuit 9 calculates the difference between the color information at a predetermined position of the second determination image and the color information at a predetermined position of the comparison image. The thinner the thickness of the colored film 102 formed on the upper surface of the susceptor 2, the smaller the value of the difference.

[0068] In step S38, the control circuit 9 determines whether or not to terminate the cleaning process based on the calculated difference. For example, when the absolute value of the calculated difference is equal to or less than a preset threshold, the control circuit 9 determines that the colored film 102 has been removed and determines to terminate the cleaning process. The threshold is, for example, 0 (zero). If it is determined in step S38 that the cleaning process is to be terminated (YES in step S38), the control circuit 9 proceeds to step S39. If it is determined in step S38 that the cleaning process is not to be terminated (NO in step S38), the control circuit 9 returns the process to step S36. That is, the control circuit 9 controls each part of the film forming apparatus 100 to continue the cleaning process until it is determined in step S38 that the cleaning process is to be terminated.

[0069] In step S39, the control circuit 9 controls each part of the film forming apparatus 100 to end the cleaning process, thereby removing the colored film 102 and the film 103 formed on the upper surface of the susceptor 2, as shown in FIG.

[0070] In step S40, the control circuit 9 determines whether or not to perform apparatus maintenance. Whether or not to perform apparatus maintenance is determined based on, for example, the number of times and duration of cleaning operations performed from the time when the susceptor 2 was replaced. If it is determined in step S40 that apparatus maintenance is to be performed (YES in step S40), the control circuit 9 ends the processing shown in Fig. 13. If it is determined in step S40 that apparatus maintenance is not to be performed (NO in step S40), the control circuit 9 returns the processing to step S32.

[0071] As described above, according to the determination method of the second embodiment, the control circuit 9 calculates the difference between the color information at a predetermined position in the second determination image and the color information at a predetermined position in the comparison image, and determines the end timing of the cleaning process based on the calculated difference. In this case, the accuracy of determining the end timing of the cleaning process can be improved.

[0072] A determination method according to a fourth example of the embodiment will be described with reference to Fig. 20. The determination method according to the fourth example of the embodiment differs from the determination method according to the third example of the embodiment in that the imaging unit 8 acquires a new comparison image each time a cleaning process is performed. In other respects, the determination method may be the same as the determination method according to the third example of the embodiment. Fig. 20 is a flowchart showing the determination method according to the fourth example of the embodiment.

[0073] 20 , in the determination method according to the fourth example of the embodiment, if it is determined in step S40 that apparatus maintenance will not be performed (NO in step S40), the control circuit 9 returns the process to step S31. That is, the image capturing unit 8 acquires a new comparison image, and the control circuit 9 determines whether or not to terminate the cleaning process based on the difference between the color information of the second determination image and the color information of the comparison image newly received from the image capturing unit 8. In this case, even if the surface condition of the susceptor 2 changes due to the cleaning process, the latest comparison image can be used, and therefore the timing to terminate the cleaning process can be determined with high accuracy.

[0074] 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.

[0075] In the above embodiment, the first information is an image of the top surface of the susceptor captured by the imaging unit, but the present disclosure is not limited to this. The first information may be information about various electromagnetic waves transmitted through or reflected by the susceptor.

[0076] In the above embodiment, the member placed in the vacuum chamber is a susceptor, but the present disclosure is not limited to this. The member placed in the vacuum chamber may be any of various members made of quartz, silicon, silicon carbide, or aluminum.

[0077] In the above embodiment, the film formation apparatus is a semi-batch type apparatus in which multiple substrates placed on a susceptor in a vacuum chamber are revolved by the susceptor and processed by passing the substrates sequentially through an adsorption region and a reaction region, but the present disclosure is not limited to this. For example, the film formation apparatus may be a single-wafer type apparatus in which substrates are processed one by one, or a batch type apparatus in which multiple substrates are processed at once. [Explanation of symbols]

[0078] 1 Vacuum container 2 susceptor 8. Imaging unit 9 Control Circuit 100 Film deposition equipment 101, 103 membrane

Claims

1. A film formation apparatus that performs a film formation process to form a film in a vacuum chamber and a cleaning process to remove the film formed in the vacuum chamber, A vacuum vessel; a member disposed within the vacuum vessel; an acquisition unit that acquires first information related to electromagnetic waves transmitted through or reflected by the member; a control circuit; Equipped with the control circuit determines at least one of a start timing and an end timing of the cleaning process based on the first information acquired by the acquisition unit. Film deposition equipment.

2. The first information is color information of the member. The film forming apparatus according to claim 1 .

3. The color information is an RGB value or an HSL value. The film forming apparatus according to claim 2 .

4. At least one of the start timing and the end timing is the end timing. The film forming apparatus according to claim 1 .

5. the control circuit determines the end timing based on a difference between color information of the member during the cleaning process and color information of the member before the film is formed. The film forming apparatus according to claim 4 .

6. the control circuit controls to terminate the cleaning process at the determined termination timing. The film forming apparatus according to claim 5 .

7. At least one of the start timing and the end timing is the start timing. The film forming apparatus according to claim 1 .

8. the control circuit determines the start timing based on a difference between color information of the member during or after the film formation process and color information of the member before the film is formed. The film forming apparatus according to claim 7 .

9. The film is a transparent film or a white film, the control circuit controls the formation of a colored film on the surface of the member before the film formation process; The film forming apparatus according to claim 1 .

10. The member is a susceptor on which a substrate is placed. The film forming apparatus according to claim 1 .

11. The member is formed of quartz, silicon, silicon carbide, or aluminum. The film forming apparatus according to claim 1 .

12. 1. A determination method for a film formation apparatus that performs a film formation process to form a film in a vacuum chamber and a cleaning process to remove the film formed in the vacuum chamber, the method comprising: acquiring first information regarding electromagnetic waves transmitted through or reflected by a member disposed within the vacuum vessel; determining at least one of a start timing and an end timing of the cleaning process based on the first information; A determination method comprising:

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