Substrate processing apparatus and substrate processing method with flow control ring

Abstract

An example of a substrate processing apparatus includes a chamber, a pedestal disposed in the chamber, a showerhead disposed above the pedestal, and a flow control ring having a shape that surrounds the pedestal, the flow control ring having a first top surface and a second top surface, the second top surface having an annular shape and disposed closer to an inner edge of the flow control ring than the first top surface at a higher level than the first top surface, the second top surface being a sloped surface with a height that decreases toward the first top surface.

Description

Technical Field

[0001] An example related to a substrate processing apparatus with a flow control loop is described. Background Technology

[0002] In plasma-enhanced atomic layer deposition (PEALD), a flow control ring (FCR) is used, for example. The FCR is a ring positioned around a substrate. Gas used to process the substrate on the substrate is guided by the FCR to an exhaust pipe. If a constant eddy current exists at the height difference between the substrate and the FCR during processing, particles are trapped and then deposited on the peripheral surface after processing. For example, particles are deposited on the inner wall of the chamber, the substrate, the FCR, the exhaust pipe, or the spray head. When a gate valve is opened, these particles are agitated and deposited onto the wafer. Summary of the Invention

[0003] Some examples described herein can address the aforementioned problems. These examples can provide substrate processing equipment and methods that can reduce substrate contamination.

[0004] In some examples, a substrate processing apparatus includes a chamber, a base disposed in the chamber, a spray head disposed above the base, and a flow control ring having a shape surrounding the base. The flow control ring has a first top surface and a second top surface, the second top surface having an annular shape and being positioned at a higher level than the first top surface and closer to the inner edge of the flow control ring. The second top surface is an inclined surface whose height decreases toward the first top surface. Attached Figure Description

[0005] Figure 1 This is a cross-sectional view illustrating an example configuration of a substrate processing apparatus;

[0006] Figure 2 yes Figure 1 Enlarged view of the FCR and other components shown;

[0007] Figure 3 This is a plan view of the first and second top surfaces of the FCR;

[0008] Figure 4 This is a graph showing the simulation results of the gas flow;

[0009] Figure 5 This is a graph showing the simulation results of a substrate processing apparatus based on a comparative example;

[0010] Figure 6 This is a table showing the occurrence of particles in substrate treatments according to four different formulations;

[0011] Figure 7 This is a partial sectional view showing another example;

[0012] Figure 8 This is a partial sectional view showing another example;

[0013] Figure 9 This is a partial sectional view showing another example; and

[0014] Figure 10 This is a partial sectional view showing another example. Detailed Implementation

[0015] The substrate processing apparatus and substrate processing method will be described with reference to the accompanying drawings. Identical or corresponding parts are indicated by the same reference numerals, and redundant descriptions may be omitted.

[0016] Figure 1 This is a cross-sectional view illustrating an example configuration of a substrate processing apparatus 10 according to an embodiment. In one example, the substrate processing apparatus 10 is configured as, for example, a film deposition apparatus for performing PEALD on a substrate. The substrate processing apparatus 10 includes a chamber (reaction chamber) 12. A spray head 14 to which RF power is applied is disposed in the chamber 12. A hole 14a through which gas can pass is formed in the spray head 14.

[0017] In chamber 12, base 16 is positioned opposite spray head 14. Base 16 is supported by sliding shaft 18. In one example, sliding shaft 18 and base 16 are raised and lowered by motor 19. Spray head 14 and base 16 form a parallel plate structure. The thickness of processing space 17, which is the gap between spray head 14 and base 16, is adjusted by raising and lowering base 16.

[0018] A gas supply section 22 is connected to the spray head 14, with an insulating component 20 disposed therebetween. The gas supply section 22 is the portion for supplying material gas between the spray head 14 and the base 16. The aforementioned processing space 17 is the space where a substrate placed on the base 16 undergoes film deposition or other processing.

[0019] An exhaust pipe 30 is disposed between the spray head 14 and the chamber 12. The exhaust pipe 30 is made of ceramic, for example. A properly compressed O-ring 32 is disposed between the exhaust pipe 30 and the spray head 14. A properly compressed O-ring 34 is disposed between the exhaust pipe 30 and the chamber 12. In one example, the exhaust pipe 30 is arranged in a ring configuration above the flow control ring 31 in a plan view.

[0020] In the plan view, the exhaust pipe 30 is formed in a ring configuration surrounding the base 16. The exhaust pipe 30 provides an annular flow path 30b surrounding the processing space 17 above the base 16. To guide gas from the processing space 17 to the annular flow path 30b, a flow control ring (FCR) 31 is provided. For example, the FCR 31 is placed on the chamber 12, with an O-ring disposed therebetween. The FCR 31 and the exhaust pipe 30 provide a slit 30a, and the gas supplied to the processing space 17 is guided through the slit 30a to the annular flow path 30b. To discharge the gas in the annular flow path 30b to the outside, an exhaust port 30c is formed in the exhaust pipe 30.

[0021] Exhaust port 30c is connected to an exhaust section 40, for example, disposed on a side surface of chamber 12. Exhaust section 40 is configured to discharge material gases used for substrate processing. Valve 42 and vacuum pump 44 are connected to exhaust section 40. The pressure in chamber 12 can be adjusted by regulating the amount of exhaust gas using valve 42 and vacuum pump 44.

[0022] Figure 2 yes Figure 1 An enlarged view of the FCR31 and other components is shown. The FCR31 includes a first top surface 31a and a second top surface 31b. In one example, the first top surface 31a is a flat surface, and the second top surface 31b is a sloping surface. The second top surface 31b is a surface at a higher level than the first top surface 31a. Figure 2 In the example shown, the second top surface 31b is an inclined surface whose height decreases towards the first top surface 31a. In other words, the height of the second top surface 31b increases towards the base 16. Figure 2 In the example shown, the second top surface 31b is a planar surface.

[0023] Figure 3 This is a plan view of the first and second top surfaces of FCR31. FCR31 surrounds base 16. The second top surface 31b is an annular surface located closer to the inner edge of FCR31 than the first top surface 31a.

[0024] A substrate processing method using the above-described substrate processing apparatus will be described. First, motor 19 is activated to raise or lower base 16, thereby aligning the top surface of base 16 and the highest portion of the second top surface 31b of FCR 31 with each other. In this way, the height difference between the top surface of base 16 and the top surface of FCR 31 is eliminated or reduced.

[0025] The substrate on the base 16 is then processed by supplying gas to the processing space 17 through the slit 14a of the spray head 14 above the base and simultaneously applying high-frequency power to the spray head 14. This process is, for example, film deposition, etching, or plasma treatment to improve film quality.

[0026] In the substrate processing, the gas in the processing space 17 flows radially in the planar view and is guided to the exhaust pipe 30 through the flow control ring 31. Because the height difference between the top surface of the base 16 and the top surface of the FCR 31 is eliminated or reduced, the formation of significant eddies is reduced near the boundary between the base 16 and the FCR 31.

[0027] Figure 4 This is a diagram illustrating the simulation results of the gas flow. As a result of setting the second top surface 31b, the gas above the base 16 flows above the FCR 31 without crossing the height difference. Thus, the formation of significant vortices is reduced near the boundary between the base 16 and the FCR 31.

[0028] Figure 5 This is a diagram illustrating simulation results of the substrate processing apparatus according to the comparative example. The configuration of FCR31 in the comparative example differs from the configuration of FCR31 in the substrate processing apparatus according to this embodiment in that there is no surface at a higher level than the first top surface 31a set closer to the base 16. Figure 5 In the example shown, there is a surface at a lower level than the first top surface 31a between the first top surface 31a and the base 16, as indicated by the arrow in the figure. Therefore, a height difference exists between the top surface of the base 16 and the top surface of the FCR 31. During substrate processing, eddies appear in the gas at this height difference. These eddies trap particles, leading to contamination inside the chamber. In one example, these eddies are likely to occur when the gap between the spray head 14 and the base 16 is less than 10.5 mm.

[0029] Figure 4 and Figure 5 The simulation shown is performed by allowing a sealing gas to flow upwards through the gap between the base and the FCR. The sealing gas is supplied to prevent process gas from flowing down to the area below the base via the gap between the base and the FCR. The sealing gas is, for example, He.

[0030] Figure 6 This is a table showing the particle occurrence during substrate processing according to four different formulations R1 to R4. The gap between the spray head and the substrate is as narrow as 7.5 mm in formulations R1 and R3, while it is as wide as 10.5 mm in formulations R2 and R4. Figure 6 The "particles" shown above "R1" and "R3" indicate the presence of significant particles under these conditions. The presence of particles is indicated by... Figure 6The wafer diagram shown at the bottom illustrates this. The experimental results indicate that particle problems are more likely to occur when the gap between the spray head and the base is small. The presence or absence of significant particles depends not only on the size of the gap between the spray head and the base but also on various other factors, such as gas flow rate. However, generally, particles become more likely to appear as the gap decreases. Even with such a small gap, the problem can be suppressed by reducing the height difference between the top surface of the base 16 and the top surface of the FCR31.

[0031] Figure 7 This is a partial cross-sectional view illustrating another example of a substrate processing apparatus. In this example, during substrate processing, the height of the top surface of the base 16 differs from the height of the highest portion of the second top surface 31c. In this example, the top surface of the base 16 is higher than the highest portion of the second top surface 31c. However, because the FCR 31 has the second top surface 31c, the height difference between the base and the FCR is smaller than the height difference when the FCR 31 does not have the second top surface 31c, thereby reducing the occurrence of eddies near the gap between the base and the FCR.

[0032] Figure 8 This is a partial cross-sectional view illustrating another example of a substrate processing apparatus. The second top surface 31d of the FCR31 is a curved surface. The curved surface reduces friction of the gas used for substrate processing generated when gas flows from above the base 16 to above the FCR31. The curved shape of the second top surface 31d helps to reduce the occurrence of eddies.

[0033] In all the examples above, by connecting the first top surface and the second top surface without any height difference, the occurrence of eddies between the first top surface and the second top surface of the FCR can be reduced.

[0034] Figure 9 This is a partial cross-sectional view illustrating another example of a substrate processing apparatus. In this example, the top surface of the base 16 includes a central top surface 16a forming a central portion of the top surface of the base 16 and a peripheral top surface 16b forming a peripheral portion of the top surface of the base 16. The peripheral top surface 16b is an annular portion including the outer edge of the base 16. The peripheral top surface 16b is a slope whose height decreases towards the outer edge of the base.

[0035] FCR31 has a first top surface 31a and a second top surface 31e. In this example, the height of the first top surface 31a and the height of the second top surface 31e are the same.

[0036] like Figure 9As shown, the substrate is processed with the height of the outermost part of the outermost top surface 16b approximately the same as the height of the top surface of the FCR31. Therefore, gas flows over the base 16 and the FCR31, and there is no height difference between the base 16 and the FCR31, thereby reducing eddies near the gap between the base 16 and the FCR31.

[0037] Figure 10 This is a partial cross-sectional view illustrating another example of a substrate processing apparatus. In this example, the base has a peripheral top surface 16b, and the FCR31 has a second top surface 31f. The peripheral top surface 16b and the second top surface 31f are connected without a height difference, thus reducing the occurrence of eddies near the gap between the base 16 and the FCR31.

[0038] exist Figure 9 and 10 In the example shown, the base has a sloping surface. If both the base and the FCR have sloping surfaces, the effect of reducing eddy currents can be increased. The sloping surface of the base can be a flat surface or a curved surface.

Claims

1. A substrate processing apparatus, comprising: room; A base set inside the room; Sprinkler heads installed above the base; The exhaust pipe is arranged in a ring above the flow control ring in the plan view; as well as A flow control ring having a shape surrounding a base, the flow control ring having a gap between the flow control ring and the base, the flow control ring having a flat first top surface and a second top surface, the second top surface having an annular shape and being positioned at a higher level than the first top surface and closer to the inner edge of the flow control ring than the first top surface, the second top surface being an inclined surface whose height decreases toward the first top surface; The flow control ring has a flat first top surface and the exhaust pipe has a slit, through which gas is guided into an annular flow path in the exhaust pipe.

2. The substrate processing apparatus according to claim 1, wherein, The second top surface is a planar surface.

3. The substrate processing apparatus according to claim 1, wherein, The second top surface is a curved surface.

4. The substrate processing apparatus according to claim 1, wherein, The first top surface and the second top surface are connected without any height difference.

5. The substrate processing apparatus according to claim 1, wherein, The height of the top surface of the base is approximately the same as the height of the highest part of the second top surface.

6. The substrate processing apparatus according to claim 1, wherein, The annular portion including the outer edge of the top surface of the base is a slope whose height decreases toward the outer edge.

7. The substrate processing apparatus according to claim 6, wherein, The inclined surface is a flat surface or a curved surface.

8. The substrate processing apparatus according to claim 1, wherein, The spray head has a slit above the base.

9. A method for substrate processing using the substrate processing apparatus according to any one of claims 1-8, comprising: The height of the top surface of the base and the height of the highest part of the inclined surface of the top surface of the flow control ring surrounding the base are made to be approximately the same, with the inclined surface set closer to the inner edge of the flow control ring. The substrate on the base is processed by supplying gas to a processing space, which is the space between the base and the spray head disposed above the base; as well as The gas in the processing space flows radially in the plan view and is guided to the exhaust pipe by the flow control loop.

10. The substrate processing method according to claim 9, wherein, Significant eddy formation is reduced near the boundary between the base and the flow control ring.

Images