Substrate processing apparatus with flow control ring, and substrate processing method

Abstract

An example of a substrate processing apparatus includes a chamber, a base provided in the chamber, a spray head provided 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 has an annular shape and is provided closer to an inner edge of the flow control ring than the first top surface and at a higher level than the first top surface. The second top surface is an inclined surface, and the height of the inclined surface decreases toward the first top surface.

Description

[Technical Field]

[0001] The description relates to an example of a substrate processing apparatus having a flow control ring. [Previous Technology]

[0002] In plasma-enhanced atomic layer deposition (PEALD), for example, a flow control ring (FCR) is used. The flow control ring is a ring provided to surround the substrate. Gas used to process the substrate on the substrate is guided by the flow control ring to the exhaust duct. If a constant vortex exists at the height difference between the substrate and the flow control ring during the process, particles can be captured after the process and then deposited on the peripheral surface. For example, particles are deposited on the chamber walls, the substrate, the flow control ring, the exhaust duct, or the spray head. When the gate valve is opened, such particles can be stirred up and deposited on the wafer. [Summary of the Invention]

[0003] Some examples described herein can address the above-mentioned problems. Some examples described herein can provide a substrate processing apparatus and a substrate processing method, which can reduce substrate contamination.

[0004] In some examples, a substrate processing apparatus includes a chamber, a base provided in the chamber, a spray head provided 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 has an annular shape and is provided closer to an inner edge of the flow control ring than the first top surface and at a higher level than the first top surface. The second top surface is an inclined surface, the height of which decreases toward the first top surface.

Implementation Method

[0006] The substrate processing equipment and substrate processing method will be described with reference to the illustrations. Identical or corresponding components are marked with the same component symbols, and redundant descriptions may be omitted.

[0007] Figure 1 is a cross-sectional view showing an example of the configuration of a substrate processing apparatus 10 according to an embodiment. In one example, the substrate processing apparatus 10 is configured as a film deposition apparatus, for example, for performing plasma-assisted atomic layer deposition (PEALD) on a substrate. The substrate processing apparatus 10 includes a chamber (reactor chamber) 12. In the chamber 12, a spray head 14 is provided to apply radio frequency (RF) power thereto. Holes 14a through which gas can pass are formed in the spray head 14.

[0008] In chamber 12, a base 16 is provided opposite to the spray head 14. The base 16 is supported by a sliding shaft 18. In one embodiment, the sliding shaft 18 and the base 16 are raised and lowered by a motor 19. The spray head 14 and the base 16 form a parallel plate structure. The thickness of the treatment space 17 (which is the gap between the spray head 14 and the base 16) is adjusted by raising and lowering the base 16.

[0009] The gas supply section 22 is connected to the spray head 14 and has an insulating component 20 disposed therebetween. The gas supply section 22 is the portion for supplying material gas to the space between the spray head 14 and the base 16. The processing space 17 described above is the space in which a substrate placed on the base 16 is subjected to film deposition or other processing.

[0010] An exhaust duct 30 is provided between the spray head 14 and the chamber 12. The exhaust duct 30 is made of, for example, ceramic. A properly compressed O-ring 32 is provided between the exhaust duct 30 and the spray head 14. A properly compressed O-ring 34 is provided between the exhaust duct 30 and the chamber 12. In one example, the exhaust duct 30 is provided in a ring configuration above the flow control ring 31 in a plan view.

[0011] The exhaust duct 30 is formed in a ring configuration in the plan view to surround the base 16. The exhaust duct 30 provides an annular flow path 30b that surrounds the processing space 17 above the base 16. To guide the gas from the processing space 17 to the annular flow path 30b, a flow control ring (FCR) 31 is provided. The flow control ring 31 is placed on the chamber 12 and has, for example, an O-ring disposed between them. The flow control ring 31 and the exhaust duct 30 provide a slit 30a, and the gas supplied to the processing space 17 is guided to the annular flow path 30b through the slit 30a. To discharge the gas in the annular flow path 30b to the outside, an exhaust port 30c is formed in the exhaust duct 30.

[0012] For example, the exhaust port 30c is connected to a gas exhaust section 40 provided on the side surface of the chamber 12. The gas exhaust section 40 is provided to exhaust the material gas used for substrate processing. A valve 42 and a vacuum pump 44 are connected to the gas exhaust section 40. The pressure in the chamber 12 can be adjusted by using the valve 42 and the vacuum pump 44 to adjust the amount of exhaust gas.

[0013] Figure 2 is an enlarged view of the flow control ring 31 and other components shown in Figure 1. The flow control ring 31 includes a first top surface 31a and a second top surface 31b. In one example, the first top surface 31a is a flat surface, while the second top surface 31b is an inclined surface. The second top surface 31b is a surface at a higher level than the first top surface 31a. In the example shown in Figure 2, the second top surface 31b is an inclined surface whose height decreases toward the first top surface 31a. In other words, the height of the second top surface 31b increases toward the base 16. In the example shown in Figure 2, the second top surface 31b is a planar surface.

[0014] Figure 3 is a plan view of the first top surface and the second top surface of the flow control ring 31. The flow control ring 31 surrounds the base 16. The second top surface 31b is an annular surface located closer to the inner edge of the flow control ring 31 than the first top surface 31a.

[0015] A substrate processing method using the substrate processing apparatus described above will be described. First, the motor 19 is activated to raise or lower the base 16, thereby aligning the top surface of the base 16 with the highest portion of the second top surface 31b of the flow control ring 31. In this way, the height difference between the top surface of the base 16 and the top surface of the flow control ring 31 is eliminated or reduced.

[0016] Then, gas is supplied to the processing space 17 through the slit 14a of the spray head 14 above the base, and high-frequency power is applied to the spray head 14 at the same time, so that the substrate on the base 16 is subjected to a process. The process is, for example, film deposition, etching, or plasma treatment for improving film quality.

[0017] In the substrate processing, the gas in the processing space 17 flows radially in the plan view and is guided to the exhaust duct 30 by the flow control ring 31. Since the height difference between the top surface of the base 16 and the top surface of the flow control ring 31 is eliminated or reduced, the formation of significant vortex is reduced near the boundary (vicinity) between the base 16 and the flow control ring 31.

[0018] Figure 4 shows the simulation results of the gas flow. Because a second top surface 31b is provided, the gas above the base 16 does not need to travel over the height difference to flow above the flow control ring 31. In this way, the formation of significant eddies is reduced near the boundary between the base 16 and the flow control ring 31.

[0019] Figure 5 shows simulation results of a substrate processing apparatus according to a comparative example. The configuration of the flow control ring 31 in the comparative example differs from the configuration of the flow control ring 31 in the substrate processing apparatus according to this embodiment, in that the comparative example does not provide a surface at a higher level than the first top surface 31a closer to the base 16. In the example shown in Figure 5, a surface at a lower level than the first top surface 31a is present between the first top surface 31a and the base 16, as indicated by the arrows in the figure. Therefore, there is a height difference between the top surface of the base 16 and the top surface of the flow control ring 31. During substrate processing, eddies occur in the gas at this height difference. These eddies trap particles, causing internal contamination. In one example, the eddies described above may occur when the gap between the spray head 14 and the base 16 is less than 10.5 millimeters (mm).

[0020] The simulations shown in Figures 4 and 5 are performed by allowing the sealing gas to flow upwards through the gap between the base and the flow control ring. The sealing gas system is supplied to prevent process gas from flowing through the gap between the base and the flow control ring to the gas below the base. For example, the sealing gas is He.

[0021] Figure 6 shows a table of particle occurrence during substrate processing according to four different configurations R1 to R4. The gap between the spray head and the base is as narrow as 7.5 mm in configurations R1 and R3, and as wide as 10.5 mm in configurations R2 and R4. In Figure 6, the "Particles" displayed above "R1" and "R3" indicates the presence of significant particles under these conditions. Particle occurrence is shown in the wafer diagram shown at the bottom of Figure 6. This experimental result shows that particle problems may occur when there is a small gap between the spray head and the base. 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 the gas flow rate. However, in general, particles become more likely to occur as the gap decreases. However, even with such small gaps, the problem can be suppressed by reducing the height difference between the top surface of the base 16 and the top surface of the flow control ring 31.

[0022] Figure 7 is a partial cross-sectional view of another example of a display substrate processing apparatus. In this example, during substrate processing, the height of the top surface of the base 16 is different 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, since the flow control ring 31 has the second top surface 31c, the height difference between the base and the flow control ring is smaller than when the flow control ring 31 does not have the second top surface 31c, thereby reducing the occurrence of eddies near the gap between the base and the flow control ring.

[0023] Figure 8 is a partial cross-sectional view of another example of a display substrate processing apparatus. The second top surface 31d of the flow control ring 31 is a curved surface. The curved surface can reduce the friction of the gas used for substrate processing that occurs when the gas flows from above the base 16 to above the flow control ring 31. The curved shape of the second top surface 31d helps to reduce the occurrence of eddies.

[0024] In all the examples described above, the occurrence of eddies between the first top surface and the second top surface of the flow control loop can be reduced by connecting the first top surface and the second top surface without a height difference.

[0025] Figure 9 is a partial cross-sectional view of another example of a display 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 includes an annular portion at the outer edge of the base 16. The peripheral top surface 16b is an inclined surface whose height decreases towards the outer edge of the base.

[0026] The flow control ring 31 has a first top surface 31a and a second top surface 31e. In this example, the height of the first top surface 31a is the same as the height of the second top surface 31e.

[0027] As shown in Figure 9, the substrate is subjected to a process in a state in which the height of the outermost portion of the peripheral top surface 16b is approximately the same as the height of the top surface of the flow control ring 31. Therefore, the gas flows above the base 16 and the flow control ring 31, and there is no height difference between them, which reduces the occurrence of eddies near the gap between the base 16 and the flow control ring 31.

[0028] Figure 10 is a partial cross-sectional view of another example of a display substrate processing apparatus. In this example, the base has a peripheral top surface 16b, and the flow control ring 31 has a second top surface 31f. The peripheral top surface 16b and the second top surface 31f are connected without any height difference, and therefore, the occurrence of eddies near the gap between the base 16 and the flow control ring 31 can be reduced.

[0029] In the examples shown in Figures 9 and 10, the base has an inclined surface. If not only the base but also the flow control ring has an inclined surface, the effect of reducing eddy current occurrence can be increased. The inclined surface of the base can be a planar surface or a curved surface. [Simplified Explanation of the Diagram]

[0005] Figure 1 is a cross-sectional view showing an example of the configuration of a substrate processing apparatus; Figure 2 is an enlarged view of the flow control ring and other components shown in Figure 1; Figure 3 is a plan view of the first and second top surfaces of the flow control ring; Figure 4 is a graph showing the simulation results of gas flow; Figure 5 is a graph showing the simulation results of a substrate processing apparatus according to a comparative example; Figure 6 is a table showing the particle occurrence in substrate processing according to four different configuration schemes; Figure 7 is a partial cross-sectional view showing another example; Figure 8 is a partial cross-sectional view showing another example; Figure 9 is a partial cross-sectional view showing another example; and Figure 10 is a partial cross-sectional view showing another example.

Claims

1. A substrate processing apparatus, comprising: One room; A base is provided in the room; A spray head is provided above the base; The system also includes a flow control ring having a shape surrounding the base, the flow control ring having a first top surface and a second top surface, the second top surface having an annular shape and being configured closer to an inner edge of the flow control ring than the first top surface, and the second top surface being configured at a higher level than the first top surface, the second top surface being an inclined surface whose height decreases toward the first top surface, wherein, in a cross-section through a vertical plane passing through a diameter of the flow control ring, the second top surface includes a curve connecting the inner edge of the flow control ring and a first top surface.

2. The substrate processing apparatus of claim 1, wherein the first top surface is a horizontal planar surface.

3. The substrate processing apparatus of claim 1, wherein the curve is a concave curve.

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

5. The substrate processing apparatus of claim 1, wherein the height of one of the top surfaces of the base is the same as the height of the highest portion of one of the second top surfaces.

6. The substrate processing apparatus as described in claim 1 further includes: An exhaust pipe is provided above the flow control ring in a ring configuration in the plan view.

7. The substrate processing apparatus of claim 1, wherein an annular portion of one outer edge of the top surface of the base is an inclined surface, the height of the inclined surface decreasing toward the outer edge.

8. The substrate processing apparatus of claim 2, wherein the first top surface extends to one of the outer edges of the flow control ring.

9. The substrate processing apparatus of claim 1, wherein the spray head has a slit above the base.

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