Substrate mounting table

Abstract

The invention provides a substrate mounting table. The temperature distribution of the substrate is controlled so as to change sharply inside and outside the partition wall. The substrate mounting table includes: a base having a mounting surface on which a substrate is mounted; an annular support member provided on the base portion and supporting the substrate along the outer peripheral side of the substrate; an annular partition wall that is provided on the placement surface and partitions the placement surface into an outer region and an inner region in the radial direction of the substrate placed on the placement surface; a plurality of protrusions which are provided on the mounting surface in the outer region and the inner region, and which support the substrate so that a gap is formed between the upper end surface of the partition wall and the substrate; an outer flow path which is provided in the base so as to communicate with the outer region and through which a heat transfer gas supplied to a space between the substrate and the placement surface flows; an inner flow path which is provided in the base so as to communicate with the inner region and through which the heat transfer gas flows; and an annular diffusion part which is provided on the base part and diffuses the heat transfer gas in the circumferential direction of the partition wall.

Description

[0001] (This application is a divisional application of the application filed on July 3, 2020, with application number 2020106367931, entitled "Substrate Placement Stage, Substrate Processing Apparatus and Temperature Control Method".) Technical Field

[0002] The following disclosure relates to a substrate mounting stage, a substrate processing apparatus, and a temperature control method. Background Technology

[0003] A substrate mounting stage is described, which is configured to have a circular partition wall on the surface of the substrate mounting side so that heat transfer gas can flow through the lower part of the substrate (Patent Document 1).

[0004] Patent Document 1: Japanese Patent Application Publication No. 2012-129547 Summary of the Invention

[0005] The problem the invention aims to solve

[0006] This disclosure provides a technique for controlling the temperature distribution of a substrate to change drastically on the inside and outside of a partition wall.

[0007] Solution for solving the problem

[0008] A substrate mounting stage of the present disclosure includes: a base having a mounting surface for mounting a substrate; an annular support member disposed in the base and supporting the substrate along the outer periphery of the substrate; an annular partition wall disposed on the mounting surface, dividing the mounting surface into an outer region and an inner region in the radial direction of the substrate mounted on the mounting surface; a plurality of protrusions disposed on the mounting surface at the outer and inner regions, supporting the substrate by creating a gap between the upper end face of the partition wall and the substrate; an outer flow path disposed in the base in communication with the outer region, for supplying heat transfer gas to flow into the space between the substrate and the mounting surface; an inner flow path disposed in the base in communication with the inner region, for supplying heat transfer gas flow; and an annular diffuser disposed in the base, allowing heat transfer gas to diffuse circumferentially along the partition wall.

[0009] The effects of the invention

[0010] According to this disclosure, it is possible to control the temperature distribution of the substrate to change drastically on the inside and outside of the partition wall. Attached Figure Description

[0011] Figure 1 This is a schematic diagram showing the entire substrate processing apparatus according to the first embodiment.

[0012] Figure 2This is a schematic diagram illustrating the flow of heat transfer gas in the substrate processing apparatus according to the first embodiment.

[0013] Figure 3 This is a top view showing the substrate mounting stage according to the first embodiment.

[0014] Figure 4 This is a longitudinal sectional view showing the substrate mounting stage according to the first embodiment.

[0015] Figure 5 This is an enlarged longitudinal sectional view showing the main parts of the substrate mounting stage according to the first embodiment.

[0016] Figure 6 This is a top view showing the substrate mounting stage according to the second embodiment.

[0017] Figure 7 This is a longitudinal sectional view showing the substrate mounting stage according to the second embodiment.

[0018] Figure 8 This is a cross-sectional view showing the main parts of the substrate mounting stage according to the second embodiment.

[0019] Figure 9 This is an enlarged cross-sectional view showing the main parts of the substrate mounting stage according to the second embodiment. Detailed Implementation

[0020] Hereinafter, the disclosed embodiments will be described in detail based on the accompanying drawings. Furthermore, these embodiments are not intended to be limited. Additionally, the various embodiments can be appropriately combined within the scope where the processing content does not contradict each other. Furthermore, in this specification and the accompanying drawings, substantially identical structures are labeled with the same reference numerals, and repeated descriptions are omitted. In the following description, when a wafer serving as a substrate is mounted on the substrate mounting stage of the substrate processing apparatus, the stage side is referred to as "lower" when viewed from the wafer, and the opposite side is referred to as "upper."

[0021] (First Embodiment)

[0022] Figure 1 This is a schematic diagram showing the overall structure of the substrate processing apparatus according to the first embodiment. (Example) Figure 1 As shown, the substrate processing apparatus 1 includes: a substrate mounting stage 5, which holds a substrate 3; a processing chamber 6, which has the substrate mounting stage 5; a processing gas supply unit 7, which supplies processing gas for processing the substrate 3 to the processing chamber 6; a heat transfer gas supply unit 8, which supplies heat transfer gas as heat transfer gas to the enclosed space (heat transfer gas space) between the substrate 3 and the substrate mounting stage 5; and a processing gas discharge unit 9, which discharges processing gas from the processing chamber 6.

[0023] A gas supply pipe 6a connected to a processing gas supply unit 7 is provided at the upper part of the processing chamber 6, and a spray plate 10 with multiple gas supply holes 10a is provided at the position opposite to the gas supply pipe 6a. A gas discharge pipe 6b connected to a processing gas discharge unit 9 is provided at the lower part of the processing chamber 6. The processing gas may be, for example, a fluorine-containing gas or an oxygen-containing gas, and compounds containing hydrogen, nitrogen, chlorine, etc. may also be added.

[0024] Figure 2 This is a schematic diagram illustrating the flow of heat transfer gas in the substrate processing apparatus 1 according to the first embodiment. For example... Figure 2 As shown, the substrate mounting stage 5 of the substrate processing apparatus 1 is connected to the heat transfer gas supply unit 8. The heat transfer gas supply unit 8 includes: a heat transfer gas supply source 11, a vacuum pump 12, a first piping 13 and a second piping 14 that connect the heat transfer gas supply source 11 and the vacuum pump 12 in parallel. An inner heat transfer gas supply unit 8a is provided on the first piping 13 side to supply heat transfer gas to the inner region F2 of the mounting surface 21a of the substrate mounting stage 5. An outer heat transfer gas supply unit 8b is provided on the second piping 14 side to supply heat transfer gas to the outer region F1 of the mounting surface 21a of the substrate mounting stage 5.

[0025] Both the first piping 13 and the second piping 14 are sequentially provided with a gas pressure control unit 15, a gas flow control unit 16, and a supply valve V1 from the heat transfer gas supply source 11 side. Both the first piping 13 and the second piping 14 have an exhaust valve V3 on the vacuum pump 12 side, and an exhaust valve V2 and a throttling element 18 are provided parallel to the exhaust valve V3 via a bypass pipe 17. The first piping 13 is connected via a connecting pipe 13a to the inner region F2 of the substrate 3 located radially on the mounting surface 21a, and the substrate 3 is placed on the substrate mounting stage 5 described later. The second piping 14 is connected via a connecting pipe 14a to the outer region F1 of the substrate 3 located radially on the mounting surface 21a, and the substrate 3 is placed on the mounting surface 21a of the substrate mounting stage 5. The heat transfer gas is used to control the temperature of the substrate 3 placed on the substrate mounting stage 5; for example, helium or argon can be used.

[0026] The heat transfer gas supply unit 8 configured as described above corrects for unintentional temperature distributions in the outer region F1 and inner region F2 of the mounting surface 21a of the substrate mounting stage 5. In cases where temperature distributions occur in the outer region F1 and inner region F2, for example, the pressure in the inner region F2 is set higher than the pressure in the outer region F1. Thus, the high-pressure heat transfer gas significantly reduces the heat in the inner region F2 of the mounting surface 21a, thereby cooling the inner region F2 compared to the outer region F1. When cooling the inner region F2 compared to the outer region F1 of the mounting surface 21a, the pressure of the heat transfer gas supplied from the heat transfer gas supply source 11 through the first piping 13 and from the connecting pipe 13a to the inner region F2 is set to high pressure, for example, around 50 [Torr], while the pressure of the heat transfer gas supplied from the heat transfer gas supply source 11 through the second piping 14 and from the connecting pipe 14a to the outer region F1 is set to low pressure, for example, around 40 [Torr]. Utilizing the pressure difference between the outer region F1 and the inner region F2, the heat transfer gas flows from the high-pressure inner region F2 towards the low-pressure outer region F1 through the gap G between the guide strip 23 and the substrate 3 (described later). The heat transfer gas flowing to the low-pressure outer region F1 passes through the connecting pipe 14a, through the second piping 14, and through the exhaust valve V2 and the throttling device 18 at the second piping 14 before being discharged by the vacuum pump 12. At this time, the exhaust valve V2 at the second piping 14 is open, and the exhaust valve V3 is closed. When the inner region F2 of the mounting surface 21a is set to high pressure and the outer region F1 is set to low pressure, the exhaust valves V2 and V3 at the first piping 13 are closed, and the heat transfer gas is not discharged through the exhaust valves V2 and V3 at the first piping 13.

[0027] On the other hand, when cooling the outer region F1 relative to the inner region F2 of the mounting surface 21a of the substrate mounting stage 5, the high-pressure side and the low-pressure side are reversed as described above. In this case, the pressure of the heat transfer gas supplied from the heat transfer gas supply source 11 through the first piping 13 and from the connecting pipe 13a to the inner region F2 is set to low pressure, for example, about 40 [Torr], and the pressure of the heat transfer gas supplied from the heat transfer gas supply source 11 through the second piping 14 and from the connecting pipe 14a to the outer region F1 is set to high pressure, for example, about 50 [Torr]. Utilizing the pressure difference between the outer region F1 and the inner region F2, the heat transfer gas flows from the high-pressure outer region F1 toward the low-pressure inner region F2 through the gap G between the guide strip 23 and the substrate 3 (described later). The heat transfer gas from the low-pressure inner region F2 side passes through the connecting pipe 13a through the first piping 13, and through the exhaust valve V2 and the throttling device 18 at the first piping 13, and is discharged by the vacuum pump 12. At this time, exhaust valve V2 at the first pipe 13 is open and exhaust valve V3 is closed. With the outer region F1 of the mounting surface 21a set to high pressure and the inner region F2 set to low pressure, exhaust valves V2 and V3 at the second pipe 14 are closed, and the heat transfer gas does not pass through exhaust valves V2 and V3 at the second pipe 14 to be discharged.

[0028] Furthermore, when fluid flows from a region of higher pressure to a region of lower pressure, a pressure difference inversely proportional to the conductance of the fluid path is generated at each point along the fluid path. When different conductances along the fluid path are connected in series, the overall pressure difference is distributed in a manner that is the reciprocal of the conductance of each individual part. Applying this principle to the mounting surface 21a of the substrate mounting stage 5 in this embodiment, consider the fluid path from the heat transfer gas supplied from the outer flow path 26 to the outer region F1 until it reaches the inner flow path 27 of the inner region F2. In this case, the fluid path is considered to be formed by the following series of paths:

[0029] 1) The path from the hole in the outer flow path 26 within the outer region F1 to the guide strip 23;

[0030] 2) The path through the gap G between the conductor strip 23 and the substrate 3;

[0031] 3) The path from the self-guided belt 23 to the hole in the inner flow path 27 in the inner region F2.

[0032] Calculating the conductance of each part, we get:

[0033] 1) 6×10 -6 [m 3 / sec];2)1×10 -6 [m 3 / sec];3)1×10 -4 [m 3The overall pressure difference is 50 [Torr] - 40 [Torr] = 10 [Torr]. Since this pressure difference is distributed in a manner that is the reciprocal of the flow conductance, a pressure difference of 8.5 [Torr], which is equivalent to 85 [%] of the overall pressure difference, is generated on the outer and inner circumferences of the guide belt 23 in this embodiment. At this time, the flow rate of the heat transfer gas generated by the overall pressure difference of 10 [Torr] is 0.67 [cc] per minute at standard atmospheric pressure.

[0034] For example, the pressure of the heat transfer gas in the inner region F2 separated by the guide strip 23 is higher than the pressure of the heat transfer gas in the outer region F1. Therefore, the center of the substrate 3 can be cooled more strongly by the heat transfer gas compared to the outer periphery. In this embodiment, as an example, the pressure of the heat transfer gas in the inner region F2 is 10 [Torr] higher than the pressure of the heat transfer gas in the outer region F1. However, this is not a limitation on the pressure difference or pressure range; the heat transfer gas supply section 8 can be modified, and the distribution of cooling efficiency of the substrate 3 can be controlled with the guide strip 23 as the boundary. This allows control of process characteristics dependent on the temperature of the substrate 3, such as the distribution of etching rate on the surface of the substrate 3.

[0035] (Structure of the substrate mounting stage)

[0036] Figure 3 This is a top view showing the substrate mounting stage 5 according to the first embodiment. Figure 4 This is a longitudinal sectional view showing the substrate mounting stage 5 according to the first embodiment, along... Figure 3 The longitudinal section view of line AA in the diagram. (See example...) Figure 3 and Figure 4 As shown, the substrate mounting stage 5 includes: a base 21 having a mounting surface 21a for mounting the substrate 3; a sealing strip 22 serving as an annular support member that supports the substrate 3 along its outer periphery; and a guide strip 23 serving as an annular partition wall that divides the mounting surface 21a into an outer region F1 and an inner region F2 in the radial direction (hereinafter referred to as the radial direction of the substrate 3) of the substrate 3 mounted on the mounting surface 21a. Furthermore, the substrate mounting stage 5 includes a plurality of first protrusions 24 and a plurality of second protrusions 25 that support the substrate 3 by creating a gap G between the upper end surface 23a of the guide strip 23 and the substrate 3.

[0037] The mounting surface 21a of the base 21 is the surface opposite to the substrate 3, and is the surface on which the substrate 3 is mounted by means of a plurality of first protrusions 24 on the guide strip 23, a plurality of second protrusions 25 on the mounting surface 21a, and the sealing strip 22. The sealing strip 22 is provided on the mounting surface 21a of the base 21, and the height from the mounting surface 21a is formed to be 15 [μm]. The guide strip 23 is provided on the mounting surface 21a of the base 21 and is arranged concentrically with the sealing strip 22.

[0038] The height of the guide strip 23 from the mounting surface 21a is formed to be 12 [μm], and a gap G of 3 [μm] is ensured between the substrate 3 supported by the sealing strip 22 and the upper end surface 23a of the guide strip 23. Furthermore, the width of the guide strip 23 in the radial direction of the substrate 3, i.e., in the radial direction of the guide strip 23, is formed to be 10 [mm]. The guide strip 23 is a structural part that acts as a resistance to the flow of heat transfer gas between the outer region F1 and the inner region F2 of the mounting surface 21a of the base 21.

[0039] A plurality of first protrusions 24 are formed in a cylindrical shape and are disposed on the upper end surface 23a of the guide strip 23. The height of the plurality of first protrusions 24 from the upper end surface 23a of the guide strip 23 is formed to be 3 [μm]. The plurality of first protrusions 24 are arranged at predetermined intervals along the circumference of the guide strip 23 and are arranged in two concentric circles relative to the center of the substrate 3. The first protrusions 24 in each row may also be staggered in position relative to the circumference of the guide strip 23, and are arranged in an alternating manner.

[0040] Multiple second protrusions 25 are formed in a cylindrical shape and are disposed on the mounting surface 21a at the outer region F1 and the inner region F2. The height of the multiple second protrusions 25 from the mounting surface 21a is formed to be 15 [μm], which is set to be equal to the height of the sealing strip 22. Figure 3 As shown, multiple second protrusions 25 are arranged radially from the center of the mounting surface 21a.

[0041] The substrate 3, placed on the mounting surface 21a, is supported by a sealing strip 22 and a plurality of first protrusions 24 and a plurality of second protrusions 25. At this time, a gap G of 3 [μm] is maintained between the upper end face 23a of the guide strip 23 and the substrate 3 in the vertical direction of the base 21, i.e., in the thickness direction of the substrate 3. By ensuring this gap G, the upper end face 23a of the guide strip 23 does not contact the substrate 3, thereby suppressing heat transfer between the substrate 3 and the guide strip 23. Therefore, it is possible to prevent a temperature singularity with a localized temperature drop from occurring directly above the guide strip 23 of the substrate 3.

[0042] Additionally, the substrate mounting stage 5 includes: an outer flow path 26 for supplying heat transfer gas to the enclosed space between the substrate 3 and the mounting surface 21a; an inner flow path 27 for supplying heat transfer gas; and an electrostatic chuck (not shown) for holding the substrate 3 mounted on the mounting surface 21a. Furthermore, the substrate mounting stage 5 includes a refrigerant flow path (not shown) for circulating refrigerant within the substrate mounting stage 5. The refrigerant flow path is connected to an external chiller (not shown) via a hose for supplying refrigerant. Heat from the plasma generated in the processing chamber 6 during the processing of the substrate 3 flows into the substrate 3 and the substrate mounting stage 5, but by circulating the refrigerant within the substrate mounting stage 5, the heat flowing in from the plasma is removed, thereby controlling the temperature of the substrate 3 and the substrate mounting stage 5 during processing to a predetermined temperature.

[0043] The outer flow path 26 is provided on the base 21 in a manner that communicates with the outer region F1, and extends through the base 21 in the vertical direction. Multiple outer flow paths 26 are arranged at predetermined intervals around the guide strip 23, for example, six are arranged at intervals with a rotation angle of 60 degrees around the center of the mounting surface 21a. The outer flow path 26 is connected to the connecting pipe 14a of the heat transfer gas supply section 8 (see reference). Figure 2 ).

[0044] The inner flow path 27 is provided in the base 21 in a manner that communicates with the inner region F2, and extends through the base 21 in the vertical direction. Multiple inner flow paths 27 are arranged at predetermined intervals around the guide strip 23, for example, six are arranged at intervals of 60 degrees around the center of the mounting surface 21a. Figure 3 As shown, the inner flow path 27 is positioned in the same circumferential direction as the outer flow path 26 on the guide strip 23. The inner flow path 27 is connected to the connecting pipe 13a of the heat transfer gas supply section 8 (see reference). Figure 2 ).

[0045] Although not shown, the electrostatic chuck has an insulator and electrodes disposed on the base 21. The electrostatic chuck holds the substrate 3 placed on the mounting surface 21a by applying a voltage to the electrodes. The chuck for holding the substrate 3 on the substrate mounting stage 5 is not limited to an electrostatic chuck; a chuck that mechanically holds the substrate 3 can also be used.

[0046] (Structure of the diffuser)

[0047] Moreover, such as Figure 3 and Figure 4As shown, the substrate mounting stage 5 includes an annular diffusion section 28 that allows heat transfer gas to diffuse circumferentially along the guide strip 23. The diffusion section 28 is a recessed portion that opens into the mounting surface 21a of the base 21 and is formed with a square groove cross-section. The diffusion section 28 includes an outer diffusion section 28a that communicates with the outer region F1 and an inner diffusion section 28b that communicates with the inner region F2.

[0048] The outer diffuser 28a diffuses the heat transfer gas flowing into the outer region F1 from the outer flow path 26 circumferentially along the outer periphery of the guide strip 23. The inner diffuser 28b diffuses the heat transfer gas flowing into the inner region F2 from the inner flow path 27 circumferentially along the inner periphery of the guide strip 23.

[0049] Figure 5 This is an enlarged longitudinal sectional view showing the main parts of the substrate mounting stage 5 according to the first embodiment. (Example) Figure 4 and Figure 5 As shown, the outer diffuser 28a includes: a first outer diffuser 28a1, which opens in the mounting surface 21a and is disposed along the outer peripheral surface of the guide strip 23; and a second outer diffuser 28a2, which opens in the mounting surface 21a and is disposed at the end of the outer flow path 26. Figure 3 As shown, the second outer diffuser portion 28a2 is disposed radially on the substrate 3 at an open interval from the inner peripheral surface of the sealing strip 22.

[0050] like Figure 4 and Figure 5 As shown, the inner diffuser 28b includes: a first inner diffuser 28b1, which opens in the mounting surface 21a and is disposed along the inner circumferential surface of the guide strip 23; and a second inner diffuser 28b2, which opens in the mounting surface 21a and is disposed at the end of the inner flow path 27. Figure 3 As shown, the second inner diffuser portion 28b2 is disposed radially on the substrate 3 at approximately the midpoint between the center of the mounting surface 21a and the inner circumferential surface of the guide strip 23.

[0051] A connecting passage 29a is provided on the base 21 along the radial direction of the substrate 3 placed on the mounting surface 21a, and the connecting passage 29a connects the first outer diffuser 28a1 and the second outer diffuser 28a2. The connecting passage 29a is a recessed portion that opens into the mounting surface 21a. Heat transfer gas flowing along the first outer diffuser 28a1 and the second outer diffuser 28a2 passes through the connecting passage 29a and flows into the first outer diffuser 28a1 and the second outer diffuser 28a2. Since the first outer diffuser 28a1, the second outer diffuser 28a2 and the connecting passage 29a are arranged to surround the outer region F1, the overall flow conductance of the outer region F1 is improved, thereby homogenizing the pressure within the outer region F1.

[0052] Furthermore, a connecting passage 29b is provided on the base 21 along the radial direction of the substrate 3 placed on the mounting surface 21a. This connecting passage 29b connects the first inner diffuser 28b1 and the second inner diffuser 28b2. The connecting passage 29b is a recessed portion that opens into the mounting surface 21a and is formed with a square groove cross-section. The heat transfer gas flowing along the first inner diffuser 28b1 and the second inner diffuser 28b2 passes through the connecting passage 29b and flows into the first inner diffuser 28b1 and the second inner diffuser 28b2. Since the first inner diffuser 28b1, the second inner diffuser 28b2, and the connecting passage 29b are arranged to surround the inner region F2, the overall flow conductance of the inner region F2 is improved, thereby homogenizing the pressure within the inner region F2.

[0053] In addition, such as Figure 3 As shown, a plurality of third protrusions 31 supporting the substrate 3 are provided on the bottom surface within the connecting passages 29a and 29b. The height of the plurality of third protrusions 31 from the bottom surface of the connecting passages 29a and 29b is formed to be 65 [μm], and the top of the third protrusion 31 is aligned with the upper end surface of the sealing strip 22, the top of each of the first protrusion 24, and the top of each of the second protrusion 25. Furthermore, the substrate mounting stage 5 is not limited to the structure having the third protrusions 31.

[0054] Furthermore, the cross-sectional shape of the diffuser 28 is not limited to a square groove shape. For example, it can also be formed as a V-groove shape, with a tapered surface whose width gradually expands toward the mounting surface 21a in the radial direction of the substrate 3. In addition, the connecting passages 29a and 29b are formed as openings in the mounting surface 21a, but they can also be provided as the internal space of the base 21.

[0055] In addition, such as Figure 3 and Figure 4 As shown, a flange-shaped fixing part 30 is formed on the outer periphery of the base 21, and a plurality of fixing holes 30a are provided at intervals around the fixing part 30 for fixing members such as bolts (not shown) to pass through.

[0056] (Diffusion effect of the diffuser section)

[0057] As described above, the conductance within the outer region F1 is increased by utilizing the first outer diffuser 28a1, the second outer diffuser 28a2, and the connecting passage 29a. Therefore, the pressure gradient of the heat transfer gas within the outer region F1 can be suppressed, thereby homogenizing the pressure of the heat transfer gas within the outer region F1. Similarly, the conductance within the inner region F2 is increased by utilizing the first inner diffuser 28b1, the second inner diffuser 28b2, and the connecting passage 29b. Therefore, the pressure gradient of the heat transfer gas within the inner region F2 is suppressed, thereby homogenizing the pressure of the heat transfer gas within the inner region F2.

[0058] Furthermore, due to manufacturing errors in the substrate mounting stage 5 and wear over time, the height of the upper end face 23a of the guide strip 23 may deviate in the circumferential direction of the guide strip 23. In this case, heat transfer gas tends to flow into the guide strip 23 from a location where the gap G between the substrate 3 and the upper end face 23a of the guide strip 23 is relatively large (where the height of the guide strip 23 is lower). Therefore, a pressure gradient of heat transfer gas may also be generated in the circumferential direction of the guide strip 23 in areas outside the guide strip 23 (within the outer region F1 and the inner region F2). Consequently, when a pressure gradient is generated in the circumferential direction of the guide strip 23 towards a location where heat transfer gas tends to flow in, the pressure distribution becomes non-axisymmetric relative to the central axis of the substrate 3, resulting in a non-axisymmetric distribution of etching characteristics.

[0059] In this case, a portion of the heat transfer gas that flows locally into the circumferential direction of the guide belt 23 also flows circumferentially along the guide belt 23 through the first outer diffuser 28a1 along the outer circumferential surface of the guide belt 23 and the first inner diffuser 28b1 along the inner circumferential surface of the guide belt 23. Therefore, even assuming flow concentration occurs on the guide belt 23, the generation of a pressure gradient of heat transfer gas in the circumferential direction of the guide belt 23 outside the guide belt 23 can be suppressed. Furthermore, in this case, a portion of the heat transfer gas that flows locally into the circumferential direction of the guide belt 23 also flows circumferentially along the guide belt 23 through the second outer diffuser 28a2 and the second inner diffuser 28b2. Therefore, the generation of a pressure gradient of heat transfer gas in the circumferential direction of the guide belt 23 is further suppressed.

[0060] (Temperature control method)

[0061] The temperature control method according to the embodiment includes the following: the substrate 3 is supported on an annular sealing strip 22 along the outer periphery of the substrate 3, the annular sealing strip 22 is provided on a base 21, the base 21 has a mounting surface 21a for mounting the substrate 3; the mounting surface 21a is divided into an outer region F1 and an inner region F2 in the radial direction of the substrate 3 mounted on the mounting surface 21a by an annular guide strip 23 provided on the mounting surface 21a; and the substrate 3 is supported by a first protrusion 24 provided on the guide strip 23 in such a way that a gap G is left between the upper end surface 23a of the guide strip 23 and the substrate 3. Furthermore, the temperature control method includes the following: using an annular diffuser 28 provided on the base 21, heat transfer gas supplied to the space between the substrate 3 and the mounting surface 21a via an outer flow path 26 and an inner flow path 27 diffuses along the circumferential direction of the guide strip 23. The outer flow path 26 and the inner flow path 27 are provided on the base 21 in a manner that communicates with the outer region F1 and the inner region F2, respectively.

[0062] (Effects of the first embodiment)

[0063] The substrate mounting stage 5 according to the first embodiment includes: a sealing strip 22 that supports the substrate 3; a guide strip 23 that divides the mounting surface 21a into an outer region F1 and an inner region F2; a plurality of second protrusions 25 that support the substrate 3 by leaving a gap G between the guide strip 23 and the substrate 3; an outer flow path 26 and an inner flow path 27 for the flow of heat transfer gas; and an annular diffuser 28 that allows the heat transfer gas to diffuse circumferentially along the guide strip 23. By using the diffuser 28 to allow the heat transfer gas to diffuse smoothly circumferentially along the guide strip 23, the conductance of the outer region F1 and the inner region F2 is increased, resulting in a relatively large conductance ratio with respect to the guide strip 23. Therefore, the pressure difference between the outer region F1 and the inner region F2 separated by the guide strip 23 can be ensured to a greater extent. Thus, the temperature distribution (pressure distribution) of the substrate 3, whose temperature is controlled by the heat transfer gas, can be controlled to change drastically in the outer region F1 and the inner region F2. Therefore, the accuracy of temperature control of substrate 3 using heat transfer gas can be improved. In particular, in the control of the process characteristics of substrate 3, there are situations where it is necessary to control the local temperature distribution of substrate 3. Therefore, since a sharp pressure difference can be applied at the boundary with the conductor strip, the range of process characteristics control can be expanded.

[0064] Furthermore, the diffusion section 28 of the substrate mounting stage 5 according to the first embodiment includes: an outer diffusion section 28a, which is provided in communication with the outer region F1, allowing heat transfer gas to diffuse circumferentially along the outer periphery of the guide strip 23; and an inner diffusion section 28b, which is provided in communication with the inner region F2, allowing heat transfer gas to diffuse circumferentially along the inner periphery of the guide strip 23. When the heat transfer gas passing through the gap G between the guide strip 23 and the substrate 3 flows to a relatively large extent locally in a portion of the circumferential direction of the guide strip 23, regardless of whether the outer region F1 or the inner region F2 is the low-pressure side, the heat transfer gas can be made to flow circumferentially along the guide strip 23 using either the outer diffusion section 28a or the inner diffusion section 28b. Therefore, it is possible to suppress the generation of a pressure gradient of heat transfer gas within the outer region F1 and the inner region F2.

[0065] Furthermore, the outer diffusion portion 28a of the substrate mounting stage 5 according to the first embodiment includes: a first outer diffusion portion 28a1, which opens at the mounting surface 21a and is provided along the outer peripheral surface of the guide strip 23; and a second outer diffusion portion 28a2, which opens at the mounting surface 21a and is provided at the end of the outer flow path 26. Thus, by utilizing the first outer diffusion portion 28a1 and the second outer diffusion portion 28a2, the heat transfer gas in the outer region F1 can be smoothly diffused in the circumferential direction of the guide strip 23. Therefore, the pressure of the heat transfer gas in the outer region F1 can be made more uniform, thereby improving the accuracy of temperature distribution control of the substrate 3. In addition, since the first outer diffusion portion 28a1 and the second outer diffusion portion 28a2 are open at the mounting surface 21a, the processability of the first outer diffusion portion 28a1 and the second outer diffusion portion 28a2 can be well ensured.

[0066] Furthermore, the inner diffusion portion 28b of the substrate mounting stage 5 according to the first embodiment includes: a first inner diffusion portion 28b1, which opens at the mounting surface 21a and is disposed along the inner circumferential surface of the guide strip 23; and a second inner diffusion portion 28b2, which opens at the mounting surface 21a and is disposed at the end of the inner flow path 27. Thus, by utilizing the first inner diffusion portion 28b1 and the second inner diffusion portion 28b2, the heat transfer gas in the inner region F2 can be smoothly diffused in the circumferential direction of the guide strip 23. Therefore, the pressure of the heat transfer gas in the inner region F2 is made more uniform, thereby improving the accuracy of temperature distribution control of the substrate 3. In addition, since the first inner diffusion portion 28b1 and the second inner diffusion portion 28b2 are open at the mounting surface 21a, the processability of the first inner diffusion portion 28b1 and the second inner diffusion portion 28b2 can be well ensured.

[0067] Furthermore, the base 21 of the substrate mounting stage 5 according to the first embodiment is provided with a connecting passage 29a, which connects the first outer diffuser 28a1 and the second outer diffuser 28a2. Therefore, within the outer region F1, the heat transfer gas flowing through the first outer diffuser 28a1 and the second outer diffuser 28a2 can flow to and from the first outer diffuser 28a1 and the second outer diffuser 28a2 via the connecting passage 29a. This makes the pressure of the heat transfer gas within the outer region F1 more uniform, thereby improving the accuracy of temperature distribution control of the substrate 3.

[0068] Furthermore, the substrate mounting stage 5 according to the first embodiment has a connecting passage 29b at its base 21, which connects the first inner diffuser 28b1 and the second inner diffuser 28b2. Therefore, within the inner region F2, the heat transfer gas flowing through the first inner diffuser 28b1 and the second inner diffuser 28b2 can flow between them via the connecting passage 29b. This makes the pressure of the heat transfer gas within the inner region F2 more uniform, thereby improving the accuracy of temperature distribution control of the substrate 3.

[0069] Furthermore, in the substrate mounting stage 5 according to the first embodiment, a plurality of first protrusions 24 are provided on the guide strip 23, and the plurality of first protrusions 24 support the substrate 3 in such a way that a gap G is left between the guide strip 23 and the substrate 3. By using a plurality of first protrusions 24 to support the substrate 3, the stability of the support state of the substrate 3 placed on the mounting surface 21a can be improved.

[0070] Furthermore, the first embodiment is not limited to including both the outer diffuser 28a and the inner diffuser 28b; the diffuser 28b may be provided only in the relatively low-pressure (high-temperature) region side of the outer region F1 and the inner region F2. For example, in the case of a substrate mounting stage 5 used to control the temperature distribution so that the inner region F2 is set to a low temperature and the outer region F1 is set to a high temperature, by having only the outer diffuser 28a and omitting the inner diffuser 28b, the structure is simplified, and the manufacturing cost of the substrate mounting stage 5 can be reduced.

[0071] (Second Implementation)

[0072] Figure 6 This is a top view showing the substrate mounting stage according to the second embodiment. Figure 7 This is a longitudinal sectional view showing the substrate mounting stage according to the second embodiment, along... Figure 6 The longitudinal sectional view along the BB line in the second embodiment differs from the diffuser 28 in the first embodiment in that the diffuser is located inside the base 21.

[0073] like Figure 6 and Figure 7 As shown, the substrate mounting stage 35 includes an annular diffusion section 38 that allows heat transfer gas to diffuse circumferentially along the guide strip 23. The diffusion section 38 is formed as the internal space of the base 21 and has a quadrilateral cross-sectional shape. For example, the diffusion section 38 may also be formed as a circular cross-sectional shape. The diffusion section 38 includes an outer diffusion section 38a that communicates with the outer region F1 and an inner diffusion section 38b that communicates with the inner region F2.

[0074] (Structure of the diffuser)

[0075] Figure 8 This is a cross-sectional view showing the main parts of the substrate mounting stage according to the second embodiment, along... Figure 7 A cross-sectional view of the CC line in the image. Figure 9 This is an enlarged cross-sectional view showing the main parts of the substrate mounting stage according to the second embodiment. For example... Figure 7 and Figure 9 As shown, the outer diffuser 38a is provided inside the base 21 in a manner that communicates with the outer flow path 26. In addition, the inner diffuser 38b is provided inside the base 21 in a manner that communicates with the inner flow path 27.

[0076] like Figure 7 and Figure 8 As shown, the outer flow path 26 has a main flow path 26a extending from the outer diffuser 38a to the bottom surface of the base 21, and the main flow path 26a is connected to the connecting pipe 14a of the heat transfer gas supply section 8 (see reference). Figure 2 The inner flow path 27 has a main flow path 27a extending from the inner diffuser 38b to the bottom surface of the base 21, and the main flow path 27a is connected to the connecting pipe 13a of the heat transfer gas supply section 8 (see reference). Figure 2 A main flow path 26a of an outer flow path 26 is provided at a predetermined position in the circumferential direction of the guide belt 23. Similarly, a main flow path 27a of an inner flow path 27 is provided at a predetermined position in the circumferential direction of the guide belt 23.

[0077] Furthermore, the outer flow path 26 has, in the radial direction of the substrate 3 placed on the mounting surface 21a, an outer branch flow path 26b extending from the outer periphery of the outer diffuser 38a to the mounting surface 21a; and an inner branch flow path 26c extending from the inner periphery of the outer diffuser 38a to the mounting surface 21a. The inner branch flow path 26c of the outer flow path 26 is disposed adjacent to the outer periphery of the guide strip 23, and is used to smoothly guide the heat transfer gas flowing into the outer region F1 from the upper end surface 23a side of the guide strip 23 through the inner branch flow path 26c into the outer diffuser 38a. Therefore, the heat transfer gas flowing into the outer diffuser 38a from the inner branch flow path 26c flows smoothly along the circumference of the guide strip 23 through the outer diffuser 38a.

[0078] Furthermore, the inner flow path 27 has, in the radial direction of the substrate 3 placed on the mounting surface 21a, an outer branch flow path 27b extending from the outer periphery of the inner diffuser 38b to the mounting surface 21a; and an inner branch flow path 27c extending from the inner periphery of the inner diffuser 38b to the mounting surface 21a. The outer branch flow path 27b of the inner flow path 27 is disposed adjacent to the inner periphery of the guide strip 23, and is used to smoothly guide the heat transfer gas flowing into the inner region F2 from the upper end surface 23a side of the guide strip 23 through the outer branch flow path 27b into the inner diffuser 38b. Therefore, the heat transfer gas flowing into the inner diffuser 38b from the outer branch flow path 27b passes through the inner diffuser 38b and flows smoothly along the circumference of the guide strip 23.

[0079] (Diffusion effect of the diffuser section)

[0080] In the second embodiment, similar to the diffuser 28 in the first embodiment, since an outer diffuser 38a is formed along the circumference of the guide band 23, the heat transfer gas supplied to the outer region F1 through the outer flow path 26 flows through the outer diffuser 38a and in the circumference of the guide band 23, smoothly distributing throughout the outer region F1 via the outer branch flow path 26b and the inner branch flow path 26c. Therefore, the pressure gradient of the heat transfer gas in the outer region F1 is suppressed, and the pressure of the heat transfer gas in the outer region F1 is homogenized. Similarly, since an inner diffuser 38b is formed along the circumference of the guide band 23, the heat transfer gas supplied to the inner region F2 through the inner flow path 27 flows through the inner diffuser 38b and in the circumference of the guide band 23, smoothly distributing throughout the inner region F2 via the outer branch flow path 27b and the inner branch flow path 27c. Therefore, the pressure gradient of the heat transfer gas generated in the inner region F2 is suppressed, thereby making the pressure of the heat transfer gas in the inner region F2 uniform.

[0081] Furthermore, when the height of the guide belt 23 deviates in the circumferential direction, a portion of the heat transfer gas that flows in locally from the circumferential direction of the guide belt 23 also flows along the circumferential direction of the guide belt 23 through the outer diffuser 38a connected to the outer region F1 and the inner diffuser 38b connected to the inner region F2. Therefore, the pressure gradient of the heat transfer gas in the circumferential direction of the guide belt 23 is suppressed, and the pressure of the heat transfer gas in the outer region F1 and the inner region F2 is homogenized.

[0082] (Effects of the second embodiment)

[0083] Since the substrate mounting stage 35 according to the second embodiment includes a diffusion portion 38, similarly to the first embodiment, the pressure difference between the outer region F1 and the inner region F2 separated by the guide strip 23 can be ensured to a greater extent. Therefore, the temperature distribution of the substrate 3 can be controlled to change drastically between the outer region F1 and the inner region F2. Consequently, the accuracy of temperature control of the substrate 3 using heat transfer gas can be improved.

[0084] Furthermore, since the diffusion portion 38 of the substrate mounting stage 35 is not located at the opening of the mounting surface 21a but is situated inside the base 21, it is possible to suppress the influence of the diffusion portion 38 on the process characteristics when processing the substrate 3 with the processing gas. In the case of a recessed portion opening at the mounting surface 21a, the width and depth of the recess can sometimes affect the process characteristics when processing the substrate 3. However, according to the second embodiment, it is advantageous to suppress the pressure gradient within the outer region F1 and the inner region F2 without affecting the mounting surface 21a.

[0085] Furthermore, the substrate mounting stage 35 can ensure a greater amount of space for the diffuser 28 to function as the diffuser 38 compared to the diffuser 28 in the first embodiment, thereby improving the circumferential flow of the heat transfer gas relative to the guide belt 23. Therefore, even if manufacturing deviations in the guide belt 23 cause a portion of the heat transfer gas to flow locally between the outer region F1 and the inner region F2 in the circumferential direction of the guide belt 23, the generation of a pressure gradient of the heat transfer gas in the circumferential direction of the guide belt 23 can be suppressed, thereby homogenizing the pressure of the heat transfer gas in the outer region F1 and the inner region F2.

[0086] Furthermore, the substrate mounting stage 5 according to the first and second embodiments includes one guide strip 23, but may also include multiple guide strips. In this case, the multiple guide strips are arranged concentrically with respect to the center of the mounting surface 21a. Additionally, the first and second embodiments may be combined as needed. For example, the substrate mounting stage may include the outer diffusion portion 38a and the inner diffusion portion 38b in the second embodiment, and the second outer diffusion portion 28a2 and the second inner diffusion portion 28b2 in the first embodiment.

Claims

1. A substrate mounting stage, comprising: The base, which has a top surface; An annular partition wall protrudes from the top surface to divide the top surface into an outer region and an inner region; Multiple first protrusions protrude from the outer and inner regions of the top surface; A sealing strip that protrudes from the top surface and extends along the periphery of the top surface; At least one outer annular groove is formed in the outer region of the top surface; At least one inner annular groove is formed in the inner region of the top surface; At least one outer gas flow path is formed in the base and communicates with the at least one outer annular groove; and At least one inner gas flow path is formed in the base and communicates with the at least one inner annular groove.

2. The substrate mounting stage according to claim 1, wherein, The at least one outer annular groove includes a first outer annular groove and a second outer annular groove that are connected to each other.

3. The substrate mounting stage according to claim 2, wherein, The first outer annular groove is connected to the second outer annular groove through multiple outer connecting passages.

4. The substrate mounting stage according to claim 3, wherein, Each of the plurality of outer connecting passages extends radially from the first outer annular groove to the second outer annular groove.

5. The substrate mounting stage according to claim 2, wherein, The at least one outer gas flow path is connected to the second outer annular groove.

6. The substrate mounting stage according to claim 5, wherein, The at least one outer gas flow path includes a plurality of outer gas flow paths arranged circumferentially.

7. The substrate mounting stage according to claim 6, wherein, The second outer annular groove surrounds the first outer annular groove.

8. The substrate mounting stage according to claim 2, wherein, The at least one inner annular groove includes a first inner annular groove and a second inner annular groove that are connected to each other.

9. The substrate mounting stage according to claim 8, wherein, The first inner annular groove is connected to the second inner annular groove through multiple inner connecting passages.

10. The substrate mounting stage according to claim 9, wherein, Each of the plurality of inner connecting passages extends radially from the first inner annular groove to the second inner annular groove.

11. The substrate mounting stage according to claim 8, wherein, The at least one inner gas flow path is connected to the second inner annular groove.

12. The substrate mounting stage according to claim 11, wherein, The at least one inner gas flow path includes a plurality of inner gas flow paths arranged in the circumferential direction.

13. The substrate mounting stage according to claim 12, wherein, The first inner annular groove surrounds the second inner annular groove.

14. The substrate mounting stage according to claim 1, wherein, The height of the annular partition wall is lower than the height of the sealing strip.

15. The substrate mounting stage of claim 14, further comprising a plurality of second protrusions extending from the annular partition wall.

16. A substrate mounting stage, comprising: The base, which has a top surface; An annular partition wall protrudes from the top surface to divide the top surface into an outer region and an inner region; Multiple first protrusions protrude from the outer and inner regions of the top surface; A sealing strip that protrudes from the top surface and extends along the periphery of the top surface; An outer annular gas diffusion path extends horizontally within the base; An inner annular gas diffusion path extends horizontally within the base; Multiple outer gas ports are formed in the outer region of the top surface and communicate with the outer annular gas diffusion path; and Multiple inner gas ports are formed in the inner region of the top surface and are connected to the inner annular gas diffusion path.

17. The substrate mounting stage according to claim 16, wherein, The height of the annular partition wall is lower than the height of the sealing strip.

18. The substrate mounting stage of claim 17, further comprising a plurality of second protrusions extending from the annular partition wall.

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