Substrate processing apparatus having a flow control ring, and substrate processing method
The substrate processing apparatus addresses substrate contamination in PEALD by employing a flow control ring with an inclined second upper surface to eliminate height differences, reducing vortex formation and particle deposition, thereby improving processing cleanliness and efficiency.
Patent Information
- Authority / Receiving Office
- JP · JP
- Patent Type
- Patents
- Current Assignee / Owner
- ASM IP HLDG BV
- Filing Date
- 2022-02-10
- Publication Date
- 2026-06-30
Smart Images
Figure 0007882660000001 
Figure 0007882660000002 
Figure 0007882660000003
Abstract
Description
Technical Field
[0001] Examples related to a substrate processing apparatus having a flow control ring are described.
Background Art
[0002] In plasma enhanced atomic layer deposition (PEALD), for example, a flow control ring (FCR) is used. The FCR is a ring provided so as to surround the susceptor. The gas used for processing the substrate on the susceptor is guided to the discharge duct by the FCR. If there is a certain vortex in the height difference between the susceptor and the FCR during the process, particles can be trapped and then deposited on the surrounding surface after the process is completed. For example, the particles are deposited on the inner wall of the chamber, the susceptor, the FCR, the discharge duct, or the shower head. These particles can be stirred when the gate valve is open and deposited on the wafer.
Summary of the Invention
Problems to be Solved by the Invention
[0003] Some of the examples described herein can address the above problems. Some of the examples described herein can provide a substrate processing apparatus and a substrate processing method capable of reducing contamination of the substrate.
Means for Solving the Problems
[0004] In some examples, the substrate processing apparatus includes a chamber, a susceptor provided in the chamber, a shower head provided above the susceptor, and a flow control ring having a shape surrounding the susceptor, the flow control ring having a first upper surface and a second upper surface, the second upper surface having an annular shape, and the second upper surface being at a higher position than the first upper surface and being closer to the inner edge of the flow control ring than the first upper surface, the second upper surface being an inclined surface, and the height of the inclined surface decreasing toward the first upper surface. [Brief explanation of the drawing]
[0005] [Figure 1] Figure 1 is a cross-sectional view showing one embodiment of the configuration of a substrate processing apparatus. [Figure 2] Figure 2 is a magnified view of the FCR and other components shown in Figure 1. [Figure 3] Figure 3 is a plan view of the first and second top surfaces of the FCR. [Figure 4] Figure 4 shows the simulation results of the gas flow. [Figure 5] Figure 5 shows the simulation results for a substrate processing apparatus according to one comparative example. [Figure 6] Figure 6 is a table showing particle generation in substrate processing using four different recipes. [Figure 7] Figure 7 is a partial cross-sectional view showing another embodiment. [Figure 8] Figure 8 is a partial cross-sectional view showing another embodiment. [Figure 9] Figure 9 is a partial cross-sectional view showing another embodiment. [Figure 10] Figure 10 is a partial cross-sectional view showing another embodiment. [Modes for carrying out the invention]
[0006] The substrate processing apparatus and substrate processing method are described with reference to the drawings. The same or corresponding components are indicated by the same reference number, and their redundant descriptions may be omitted.
[0007] Figure 1 is a cross-sectional view showing one embodiment of the configuration of a substrate processing apparatus 10 according to one embodiment. In this embodiment, the substrate processing apparatus 10 is configured as a film deposition apparatus that performs PEALD on a substrate, for example. The substrate processing apparatus 10 includes a chamber (reactor chamber) 12. A showerhead 14 to which RF power is applied is provided inside the chamber 12. Holes 14a through which gas can pass are formed inside the showerhead 14.
[0008] A susceptor 16 is positioned inside the chamber 12, facing the shower head 14. The susceptor 16 is supported by a sliding shaft 18. In one embodiment, the sliding shaft 18 and the susceptor 16 are raised and lowered by a prime mover 19. The shower head 14 and the susceptor 16 form a parallel plate structure. The thickness of the processing space 17, which is the gap between the shower head 14 and the susceptor 16, is adjusted by raising and lowering the susceptor 16.
[0009] The gas supply unit 22 is connected to the shower head 14, with an insulating component 20 placed between them. The gas supply unit 22 is the part that supplies the raw material gas between the shower head 14 and the susceptor 16. The processing space 17 is the space in which the substrate placed on the susceptor 16 undergoes film deposition or other processing.
[0010] A discharge duct 30 is provided between the shower head 14 and the chamber 12. The discharge duct 30 is made of, for example, ceramic. A properly compressed O-ring 32 is provided between the discharge duct 30 and the shower head 14. A properly compressed O-ring 34 is provided between the discharge duct 30 and the chamber 12. In one embodiment, the discharge duct 30 is provided above the flow control ring 31 in an annular configuration in the plan view.
[0011] The discharge duct 30 is formed in an annular configuration in the plan view and surrounds the susceptor 16. The discharge duct 30 provides an annular flow path 30b surrounding the processing space 17 above the susceptor 16. A flow control ring (FCR) 31 is provided to guide the gas from the processing space 17 to the annular flow path 30b. For example, the FCR 31 is fixed on the chamber 12 and an O-ring is positioned between them. The FCR 31 and the discharge duct 30 provide a slit 30a through which the gas supplied to the processing space 17 is guided to the annular flow path 30b. A discharge port 30c is formed in the discharge duct 30 to release the gas in the annular flow path 30b to the outside.
[0012] The discharge port 30c is connected to a gas discharge section 40, which is provided, for example, on the side of the chamber 12. The gas discharge section 40 is provided to release the raw material gas used in substrate processing. A valve 42 and a vacuum pump 44 are connected to the gas discharge section 40. The pressure inside the chamber 12 can be adjusted by adjusting the amount of exhaust gas with the valve 42 and the vacuum pump 44.
[0013] Figure 2 is an enlarged view of the FCR31 and other components shown in Figure 1. The FCR31 includes a first upper surface 31a and a second upper surface 31b. In one embodiment, the first upper surface 31a is a flat surface and the second upper surface 31b is an inclined surface. The second upper surface 31b is a surface located higher than the first upper surface 31a. In the embodiment shown in Figure 2, the second upper surface 31b is an inclined surface, and the height of this inclined surface decreases toward the first upper surface 31a. In other words, the height of the second upper surface 31b increases toward the susceptor 16. In the embodiment shown in Figure 2, the second upper surface 31b is a flat surface.
[0014] Figure 3 is a plan view of the first and second upper surfaces of the FCR31. The FCR31 surrounds the susceptor 16. The second upper surface 31b is an annular surface located closer to the inner edge of the FCR31 than the first upper surface 31a.
[0015] A substrate processing method using the above-described substrate processing apparatus will now be explained. First, the prime mover 19 is started, and the susceptor 16 is raised or lowered, thereby aligning the upper surface of the susceptor 16 with the highest part of the second upper surface 31b of the FCR 31. In this way, the height difference between the upper surface of the susceptor 16 and the upper surface of the FCR 31 is eliminated or reduced.
[0016] Next, the substrate on the susceptor 16 is processed by supplying gas through the slit 14a of the shower head 14 above the susceptor to the processing space 17 and at the same time applying high-frequency power to the shower head 14. The processing is, for example, film deposition, etching, or plasma processing for improving the quality of the film.
[0017] In substrate processing, the gas in the processing space 17 flows radially in a plan view and is guided to the discharge duct 30 by the flow control ring 31. Since the height difference between the upper surface of the susceptor 16 and the upper surface of the FCR 31 is eliminated or reduced, significant vortex formation is reduced near the boundary between the susceptor 16 and the FCR 31.
[0018] FIG. 4 is a diagram showing the simulation result of the gas flow. As a result of providing the second upper surface 31b, the gas above the susceptor 16 flows above the FCR 31 without exceeding the height difference. In this way, significant vortex formation is reduced near the boundary between the susceptor 16 and the FCR 31.
[0019] FIG. 5 is a diagram showing the simulation result of a substrate processing apparatus according to a comparative example. The configuration of the FCR 31 in this comparative example is different from the configuration of the FCR 31 of the substrate processing apparatus according to this embodiment in that there is no surface at a position higher than the first upper surface 31a provided closer to the susceptor 16. In the example shown in FIG. 5, as indicated by the arrow in the drawing, there is a surface at a position lower than the first upper surface 31a between the first upper surface 31a and the susceptor 16. Therefore, there is a height difference between the upper surface of the susceptor 16 and the upper surface of the FCR 31. In substrate processing, vortices are generated in the gas due to the height difference. The vortices capture particles, which cause contamination inside the chamber. In one example, the above-mentioned vortices are likely to occur when the gap between the shower head 14 and the susceptor 16 is less than 10.5 mm.
[0020] The simulations shown in FIGS. 4 and 5 are performed by flowing the seal gas upward in the gap between the susceptor and the FCR. The seal gas is a gas supplied to prevent the process gas from flowing downward from the susceptor through the gap between the susceptor and the FCR. The seal gas is, for example, He.
[0021] FIG. 6 is a table showing particle generation in substrate processing according to four different recipes R1 to R4. The gap between the shower head and the susceptor is narrow at 7.5 mm in recipes R1 and R3, while the gap is wide at 10.5 mm in recipes R2 and R4. In FIG. 6, the "particles" shown above "R1" and "R3" indicate that significant particles are generated under these conditions. Particle generation is shown in the wafer map shown at the bottom of FIG. 6. This experimental result shows that when the gap between the shower head and the susceptor is small, there is a high possibility of particle problems. The presence or absence of significant particles depends not only on the size of the gap between the shower head and the susceptor but also on various other factors such as gas flow rate. However, generally, as the gap decreases, the possibility of particle generation becomes higher. However, even if the gap is so small, the problem can be suppressed by reducing the height difference between the upper surface of the susceptor 16 and the upper surface of the FCR 31.
[0022] FIG. 7 is a partial cross-sectional view showing another embodiment of the substrate processing apparatus. In this embodiment, in substrate processing, the height of the upper surface of the susceptor 16 is not the same as the height of the highest part of the second upper surface 31c. In this embodiment, the upper surface of the susceptor 16 is higher than the highest part of the second upper surface 31c. However, since the FCR 31 has the second upper surface 31c, the height difference between the susceptor and the FCR is smaller than when the FCR 31 does not have the second upper surface 31c. As a result, the generation of vortices in the vicinity of the gap between the susceptor and the FCR can be reduced.
[0023] Figure 8 is a partial cross-sectional view showing another embodiment of the substrate processing apparatus. The second upper surface 31d of the FCR31 is curved. The curved surface can reduce friction of the gas used for substrate processing, which occurs when the gas flows from above the susceptor 16 to above the FCR31. The curved shape of the second upper surface 31d contributes to reducing vortex generation.
[0024] In all of the above embodiments, the generation of vortices between the first upper surface and the second upper surface of the FCR can be reduced by connecting the first upper surface and the second upper surface without any difference in height.
[0025] Figure 9 is a partial cross-sectional view showing another embodiment of the substrate processing apparatus. In this embodiment, the upper surface of the susceptor 16 includes a central upper surface 16a that forms the central portion of the upper surface of the susceptor 16, and a peripheral upper surface 16b that forms the peripheral portion of the upper surface of the susceptor 16. The peripheral upper surface 16b is an annular portion that includes the outer edge of the susceptor 16. The peripheral upper surface 16b is a sloped surface, and the height of the sloped surface decreases toward the outer edge of the susceptor.
[0026] The FCR31 has a first upper surface 31a and a second upper surface 31e. In this embodiment, the height of the first upper surface 31a and the height of the second upper surface 31e are the same.
[0027] As shown in Figure 9, the substrate is processed with the height of the outermost part of the peripheral upper surface 16b being approximately the same as the height of the upper surface of FCR31. Therefore, the gas flows over the susceptor 16 and FCR31, and there is no height difference between the susceptor 16 and FCR31. As a result, the generation of vortices near the gap between the susceptor 16 and FCR31 can be reduced.
[0028] Figure 10 is a partial cross-sectional view showing another embodiment of the substrate processing apparatus. In this embodiment, the susceptor has a peripheral upper surface 16b, and the FCR 31 has a second upper surface 31f. The peripheral upper surface 16b and the second upper surface 31f are connected without any difference in height, and thus the generation of vortices near the gap between the susceptor 16 and the FCR 31 can be reduced.
[0029] In the embodiments shown in Figures 9 and 10, the susceptor has an inclined surface. If both the susceptor and the FCR have inclined surfaces, the effect of reducing vortex generation can be increased. The inclined surface of the susceptor may be a flat surface or a curved surface.
Claims
1. A substrate processing apparatus, Chamber and A susceptor provided inside the chamber, A shower head is provided above the susceptor, A flow control ring having a shape that surrounds the susceptor, wherein the flow control ring has a first upper surface and a second upper surface, the second upper surface has an annular shape, and the second upper surface is located higher than the first upper surface and closer to the inner edge of the flow control ring than the first upper surface, the second upper surface is an inclined surface, and the height of the inclined surface decreases toward the first upper surface, A substrate processing apparatus further comprising a discharge duct located above the flow control ring in an annular configuration in a plan view.
2. The substrate processing apparatus according to claim 1, wherein the second upper surface is a flat surface.
3. The substrate processing apparatus according to claim 1, wherein the second upper surface is a curved surface.
4. The substrate processing apparatus according to claim 1, wherein the first upper surface and the second upper surface are connected without any difference in height.
5. The substrate processing apparatus according to claim 1, wherein the height of the upper surface of the susceptor and the height of the highest part of the second upper surface are the same.
6. The substrate processing apparatus according to claim 1, wherein the annular portion including the outer edge of the upper surface of the susceptor is a gradient surface, and the height of the gradient surface decreases toward the outer edge.
7. The substrate processing apparatus according to claim 6, wherein the gradient surface is a flat surface or a curved surface.
8. The substrate processing apparatus according to claim 1, wherein the shower head has a slit above the susceptor.
9. A substrate processing method, The height of the upper surface of the susceptor and the height of the highest part of the inclined surface of the upper surface of the flow control ring surrounding the susceptor are to be made to match, such that the inclined surface is located closer to the inner edge of the flow control ring. The process involves supplying gas to a processing space to cause the substrate on the susceptor to undergo processing, wherein the processing space is the space between the susceptor and a shower head provided above the susceptor. A substrate processing method comprising: causing the gas in the processing space to flow radially in a plan view, and guiding it to a discharge duct provided above the flow control ring in an annular configuration in a plan view by the flow control ring.
10. The substrate processing method according to claim 9, wherein the formation of significant vortices is reduced near the boundary between the susceptor and the flow control ring.