Substrate processing apparatus and substrate processing method

Abstract

To provide a technology that can adjust the in-plane distribution of substrate temperature.SOLUTION: A substrate processing apparatus according to an aspect of the present disclosure comprises: a vacuum vessel; a rotary table installed in the vacuum vessel and having a mounting surface on the top surface on which substrates are placed; a heating section installed below the rotary table to heat the substrate by radiation; and a thermal conductivity adjustment section that adjusts the in-plane distribution of thermal conductivity of the gap between the rotary table and the substrate.SELECTED DRAWING: Figure 7

Description

Technical Field

[0001] The present disclosure relates to a substrate processing apparatus and a substrate processing method.

Background Art

[0002] There is known an apparatus for forming various films on a substrate by rotating a rotating table on which a plurality of substrates are placed to revolve each substrate, and repeatedly passing a supply region of a processing gas arranged along the radial direction of the rotating table (see, for example, Patent Document 1). The apparatus of Patent Document 1 includes a heating unit that heats a plurality of substrates by radiation, and a radiation adjustment unit that adjusts the amount of radiation from the heating unit to the plurality of substrates.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] The present disclosure provides a technique capable of adjusting the in-plane distribution of the substrate temperature.

Means for Solving the Problems

[0005] A substrate processing apparatus according to an aspect of the present disclosure includes a vacuum chamber, a rotating table provided in the vacuum chamber and having a placement surface for placing a substrate formed on an upper surface thereof, a heating unit provided below the rotating table for heating the substrate by radiation, and a thermal conductivity adjustment unit for adjusting the in-plane distribution of the thermal conductivity of a gap between the rotating table and the substrate.

Effects of the Invention

[0006] According to the present disclosure, the in-plane distribution of the substrate temperature can be adjusted.

Brief Description of the Drawings

[0007]

Figure 1

Figure 2

Figure 3

Figure 4

Figure 5

Figure 6

Figure 7

Figure 8

Figure 9

Figure 10

Figure 11

Figure 12

Embodiments for Carrying Out the Invention

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

[0009] 〔Substrate Processing Apparatus〕 A substrate processing apparatus according to an embodiment will be described. FIG. 1 is a cross-sectional view showing a configuration example of the substrate processing apparatus according to the embodiment. FIG. 2 is a perspective view showing the configuration inside the vacuum chamber 1 of the substrate processing apparatus of FIG. 1. FIG. 3 is a plan view showing the configuration inside the vacuum chamber 1 of the substrate processing apparatus of FIG. 1. In FIGS. 2 and 3, the illustration of the top plate 11 is omitted.

[0010] Referring to FIGS. 1 to 3, the substrate processing apparatus includes a flat vacuum chamber 1 having a substantially circular planar shape, and a rotary table 2 provided inside the vacuum chamber 1 and having a rotation center at the center of the vacuum chamber 1.

[0011] The vacuum chamber 1 has a container body 12 having a bottomed cylindrical shape, and a top plate 11 that is detachably and airtightly disposed on the upper surface of the container body 12 via a seal member 13 (FIG. 1) such as an O-ring.

[0012] The rotary table 2 is formed of, for example, quartz. The rotary table 2 is fixed to a cylindrical core portion 21 at the center. The core portion 21 is fixed to the upper end of a rotary shaft 22 extending in the vertical direction. The rotary shaft 22 penetrates the bottom 14 of the vacuum chamber 1, and its lower end is attached to a drive unit 23 that rotates the rotary shaft 22 (FIG. 1) around the vertical axis. The rotary shaft 22 and the drive unit 23 are housed in a cylindrical case body 20 having an open upper surface. The flange portion provided on the upper surface of the case body 20 is airtightly attached to the lower surface of the bottom 14 of the vacuum chamber 1, and the airtight state between the internal atmosphere and the external atmosphere of the case body 20 is maintained.

[0013] On the upper surface of the rotary table 2, as shown in FIGS. 2 and 3, a circular recess 24 for placing a plurality of (six in the illustrated example) substrates W along the rotation direction (circumferential direction) is provided. The substrate W is, for example, a semiconductor wafer. In FIG. 3, for the sake of convenience, only one recess 24 is shown with the substrate W. Each recess 24 is provided at a position horizontally displaced with respect to the rotation axis 22 of the rotary table 2. Each recess 24 has an inner diameter slightly larger than the diameter of the substrate W, for example, 4 mm larger, and a depth substantially equal to the thickness of the substrate W. Therefore, when the substrate W is accommodated in the recess 24, the surface of the substrate W and the surface of the rotary table 2 (the region where the substrate W is not placed) are at the same height. The bottom surface of each recess 24 serves as a placement surface 2a (FIG. 7) for placing the substrate W. Through holes (not shown in any figure), for example, three lifting pins for supporting the back surface of the substrate W and lifting and lowering the substrate W, are formed in the bottom surface of the recess 24.

[0014] As shown in FIGS. 2 and 3, above the rotary table 2, reaction gas nozzles 31, 32 and separation gas nozzles 41, 42 made of, for example, quartz are arranged at intervals in the circumferential direction of the vacuum chamber 1 (the rotation direction of the rotary table 2 indicated by the arrow A in FIG. 3). In the illustrated example, in the clockwise direction (the rotation direction of the rotary table 2) from the transfer port 15 described later, the separation gas nozzle 41, the reaction gas nozzle 31, the separation gas nozzle 42, and the reaction gas nozzle 32 are arranged in this order. Gas introduction ports 31a, 32a, 41a, 42a (FIG. 3), which are the base ends of these reaction gas nozzles 31, 32 and separation gas nozzles 41, 42, are fixed to the outer peripheral wall of the container body 12. Then, the reaction gas nozzles 31, 32 and the separation gas nozzles 41, 42 are introduced into the vacuum chamber 1 from the outer peripheral wall of the vacuum chamber 1 and are attached so as to extend horizontally with respect to the rotary table 2 along the radial direction of the container body 12.

[0015] The reaction gas nozzle 31 is connected to a supply source (not shown) of the source gas via a pipe, a flow controller, etc. (not shown). As the source gas, for example, a silicon-containing gas or a metal-containing gas can be used.

[0016] The reaction gas nozzles 32 are connected to a supply source of nitriding gas (not shown) via pipes, flow controllers, etc. (not shown). As the nitriding gas, for example, ammonia (NH3) gas can be used.

[0017] The separation gas nozzles 41 and 42 are both connected to a supply source of separation gas (not shown) via pipes, flow control valves, etc. (not shown). As the separation gas, for example, argon (Ar) gas or nitrogen (N2) gas can be used.

[0018] The reaction gas nozzles 31 and 32 are provided with a plurality of discharge holes 31h and 32h (Fig. 4) that open toward the rotary table 2, and are arranged at intervals of, for example, 10 mm along the length direction of the reaction gas nozzles 31 and 32. The lower region of the reaction gas nozzle 31 becomes a raw material gas adsorption region P1 for adsorbing the raw material gas to the substrate W. The lower region of the reaction gas nozzle 32 becomes a nitriding gas supply region P2 for nitriding the raw material gas adsorbed to the substrate W in the raw material gas adsorption region P1.

[0019] Referring to Figs. 2 and 3, two convex portions 4 are provided in the vacuum chamber 1. The convex portions 4 are attached to the back surface of the top plate 11 so as to protrude toward the rotary table 2 in order to constitute a separation region D together with the separation gas nozzles 41 and 42. Further, the convex portion 4 has a fan-shaped planar shape with the top portion cut in an arc shape. In the embodiment, the inner arc is connected to a protruding portion 5 (described later), and the outer arc is arranged along the inner peripheral surface of the chamber body 12 of the vacuum chamber 1.

[0020] FIG. 4 shows a cross-section of the vacuum chamber 1 along the concentric circles of the rotary table 2 from the reaction gas nozzle 31 to the reaction gas nozzle 32. As shown in FIG. 4, a convex portion 4 is attached to the back surface of the top plate 11. Therefore, inside the vacuum chamber 1, there is a flat and low ceiling surface (the first ceiling surface 44) which is the lower surface of the convex portion 4, and ceiling surfaces (the second ceiling surfaces 45) which are higher than the first ceiling surface 44 and are located on both circumferential sides of the first ceiling surface 44. The first ceiling surface 44 has a fan-shaped planar shape with an arc-shaped cut at the top. Also, as shown in the drawing, a groove portion 43 formed to extend in the radial direction is formed at the center in the circumferential direction of the convex portion 4, and the separation gas nozzle 42 is accommodated in the groove portion 43. Similarly, a groove portion 43 is also formed in the other convex portion 4, and the separation gas nozzle 41 is accommodated in the groove portion 43. Further, reaction gas nozzles 31 and 32 are respectively provided in the space below the second ceiling surface 45. These reaction gas nozzles 31 and 32 are provided in the vicinity of the substrate W at a distance from the second ceiling surface 45. As shown in FIG. 4, the reaction gas nozzle 31 is provided in the space 481 below the second ceiling surface 45 on the right side of the convex portion 4, and the reaction gas nozzle 32 is provided in the space 482 below the second ceiling surface 45 on the left side of the convex portion 4.

[0021] Also, a plurality of discharge holes 42h (see FIG. 4) that open toward the rotary table 2 are arranged along the length direction of the separation gas nozzle 42 at intervals of, for example, 10 mm in the separation gas nozzle 42 accommodated in the groove portion 43 of the convex portion 4. Similarly, a plurality of discharge holes 41h that open toward the rotary table 2 are arranged along the length direction of the separation gas nozzle 41 at intervals of, for example, 10 mm in the separation gas nozzle 41 accommodated in the groove portion 43 of the other convex portion 4.

[0022] The first ceiling surface 44 forms a separation space H, which is a narrow space, with respect to the rotary table 2. When Ar gas is supplied from the discharge hole 42h of the separation gas nozzle 42, the Ar gas flows through the separation space H toward the spaces 481 and 482. At this time, since the volume of the separation space H is smaller than the volumes of the spaces 481 and 482, the pressure in the separation space H can be made higher than the pressures in the spaces 481 and 482 by the Ar gas. That is, a separation space H with a high pressure is formed between the spaces 481 and 482. Further, the Ar gas flowing out from the separation space H to the spaces 481 and 482 acts as a counterflow to the source gas from the source gas adsorption region P1 and the nitriding gas from the nitriding gas supply region P2. Therefore, the source gas from the source gas adsorption region P1 and the nitriding gas from the nitriding gas supply region P2 are separated by the separation space H. Thus, the mixing and reaction of the source gas and the nitriding gas in the vacuum chamber 1 are suppressed.

[0023] The height h1 of the first ceiling surface 44 with respect to the upper surface of the rotary table 2 is set to a height suitable for making the pressure in the separation space H higher than the pressures in the spaces 481 and 482 in consideration of the pressure in the vacuum chamber 1 during film formation, the rotation speed of the rotary table 2, the flow rate of the separation gas (Ar gas), and the like.

[0024] On the other hand, a protrusion 5 (FIGS. 2 and 3) surrounding the outer periphery of the core portion 21 that fixes the rotary table 2 is provided on the lower surface of the top plate 11. In the embodiment, the protrusion 5 is continuous with the portion on the rotation center side of the convex portion 4, and its lower surface is formed at the same height as the first ceiling surface 44.

[0025] FIG. 1, which was referred to earlier, is a cross-sectional view taken along line I-I' of FIG. 3 and shows the region where the second ceiling surface 45 is provided. On the other hand, FIG. 5 is a cross-sectional view showing the region where the first ceiling surface 44 is provided. As shown in FIG. 5, at the periphery of the fan-shaped convex portion 4 (the portion on the outer edge side of the vacuum vessel 1), a bent portion 46 that bends in an L-shape so as to face the outer end surface of the rotary table 2 is formed. Similar to the convex portion 4, the bent portion 46 suppresses the intrusion of the reaction gas from both sides of the separation region D and suppresses the mixing of the source gas and the nitriding gas. Since the fan-shaped convex portion 4 is provided on the top plate 11 and the top plate 11 can be removed from the container body 12, there is a slight gap between the outer peripheral surface of the bent portion 46 and the container body 12. The gap between the inner peripheral surface of the bent portion 46 and the outer end surface of the rotary table 2 and the gap between the outer peripheral surface of the bent portion 46 and the container body 12 are set to dimensions similar to the height of the first ceiling surface 44 with respect to the upper surface of the rotary table 2, for example.

[0026] The inner peripheral wall of the container body 12 is formed as a vertical surface close to the outer peripheral surface of the bent portion 46 in the separation region D (FIG. 5), but in the portion outside the separation region D, for example, it is recessed outward from the portion facing the outer end surface of the rotary table 2 to the bottom 14 (FIG. 1). Hereinafter, for the sake of convenience of explanation, the recessed portion having a generally rectangular cross-sectional shape will be referred to as the exhaust region E. Specifically, the exhaust region communicating with the source gas adsorption region P1 is referred to as the first exhaust region E1, and the region communicating with the nitriding gas supply region P2 is referred to as the second exhaust region E2. At the bottoms of these first exhaust region E1 and second exhaust region E2, as shown in FIGS. 1 to 3, a first exhaust port 61 and a second exhaust port 62 are formed, respectively. The first exhaust port 61 and the second exhaust port 62 are each connected to, for example, a vacuum pump 64, which is a vacuum exhaust unit, via an exhaust pipe 63 as shown in FIG. 1. Further, a pressure controller 65 is provided in the exhaust pipe 63, and the pressure inside the vacuum vessel 1 is configured to be adjustable.

[0027] In the space between the rotary table 2 and the bottom 14 of the vacuum chamber 1, a heater unit 7 which is a heating section is provided as shown in FIGS. 1 and 5. The heater unit 7 heats the substrate W on the rotary table 2 to a temperature determined by the process recipe by radiation.

[0028] FIG. 6 is a view showing an example of the arrangement of the heater unit 7. FIG. 6 is a plan view showing the position of the heater unit 7 with respect to the rotary table 2 when viewed from a direction perpendicular to the upper surface of the rotary table 2. As shown in FIG. 6, the heater unit 7 has a plurality (for example, four) of heaters 111, 112, 113, 114. The plurality of heaters 111, 112, 113, 114 are provided on concentric circles centered on the rotation axis 22 of the rotary table 2. The plurality of heaters 111, 112, 113, 114 are provided in this order from the center side to the outer peripheral side of the rotary table 2. The plurality of heaters 111, 112, 113, 114 are, for example, independently controlled in output.

[0029] An annular cover member 71 is provided below the vicinity of the periphery of the rotary table 2 (FIG. 5). The cover member 71 partitions the atmosphere from the upper space of the rotary table 2 to the first exhaust region E1 and the second exhaust region E2 and the atmosphere in which the heater unit 7 is placed, and suppresses the intrusion of gas into the lower region of the rotary table 2. The cover member 71 includes an inner member 71a provided so as to face the outer edge of the rotary table 2 and the outer peripheral side of the outer edge from below, and an outer member 71b provided between the inner member 71a and the inner peripheral surface of the vacuum chamber 1. The outer member 71b is provided in the separation region D in the vicinity of the bent portion 46 formed on the outer edge of the convex portion 4 below the bent portion 46. The inner member 71a surrounds the heater unit 7 over the entire circumference below the outer edge of the rotary table 2 (and below a portion slightly outside the outer edge).

[0030] The bottom portion 14 at a site on the side of the rotation center rather than the space where the heater unit 7 is disposed protrudes upward to form a protruding portion 12a so as to approach the core portion 21 near the center of the lower surface of the rotary table 2. A narrow space is formed between the protruding portion 12a and the core portion 21, and the gap between the inner peripheral surface of the through-hole of the rotary shaft 22 penetrating the bottom portion 14 and the rotary shaft 22 is narrow, and these narrow spaces communicate with the case body 20. And a purge gas supply pipe 72 for supplying and purging Ar gas, which is a purge gas, into the narrow space is provided in the case body 20. Further, a plurality of purge gas supply pipes 73 for purging the arrangement space of the heater unit 7 are provided at predetermined angular intervals in the circumferential direction below the heater unit 7 on the bottom portion 14 of the vacuum vessel 1 (only one purge gas supply pipe 73 is shown in FIG. 5). Further, between the heater unit 7 and the rotary table 2, a lid member 7a is provided to cover the space between the inner peripheral wall of the outer member 71b (the upper surface of the inner member 71a) and the upper end of the protruding portion 12a in the circumferential direction in order to suppress the intrusion of gas into the region where the heater unit 7 is provided. The lid member 7a is formed of, for example, quartz.

[0031] Further, a separation gas supply pipe 51 is connected to the center of the top plate 11 of the vacuum vessel 1, and is configured to supply Ar gas, which is a separation gas, to the space 52 between the top plate 11 and the core portion 21. The separation gas supplied to the space 52 is discharged toward the periphery along the surface on the wafer mounting region side of the rotary table 2 through the narrow gap 50 between the protruding portion 5 and the rotary table 2. The gap 50 can be maintained at a higher pressure than the spaces 481 and 482 by the separation gas. Therefore, the gap 50 suppresses the mixing of the source gas supplied to the source gas adsorption region P1 and the nitriding gas supplied to the nitriding gas supply region P2 through the central region C. That is, the gap 50 (or the central region C) functions in the same manner as the separation space H (or the separation region D).

[0032] Furthermore, as shown in FIGS. 2 and 3, a transfer port 15 for transferring the substrate W between the external transfer arm 10 and the rotary table 2 is formed in the side wall of the vacuum chamber 1. The transfer port 15 is opened and closed by a gate valve (not shown). Below the rotary table 2, at a position corresponding to the transfer position of the substrate W, a lift pin for lifting the substrate W from the back surface through the recess 24 and its lifting mechanism (both not shown) are provided.

[0033] In addition, the substrate processing apparatus includes a thermal conductivity adjustment unit 90 that adjusts the in-plane distribution of the thermal conductivity of the gap between the rotary table 2 and the substrate W. The thermal conductivity adjustment unit 90 will be described later.

[0034] Also, as shown in FIG. 1, the substrate processing apparatus is provided with a control unit 100 composed of a computer for controlling the operation of the entire apparatus. In the memory of the control unit 100, a program for causing the substrate processing apparatus to perform a film forming method described later is stored under the control of the control unit 100. The program is composed of a group of steps so as to execute the film forming method described later. The program is stored in a medium 102 such as a hard disk, a compact disk, a magneto-optical disk, a memory card, or a flexible disk, read into the storage unit 101 by a predetermined reading device, and installed in the control unit 100.

[0035] 〔Thermal Conductivity Adjustment Unit〕 With reference to FIGS. 7 and 8, the thermal conductivity adjustment unit 90 will be described. FIG. 7 is a cross-sectional view showing the thermal conductivity adjustment unit 90. FIG. 8 is a plan view showing the thermal conductivity adjustment unit 90.

[0036] Based on the in-plane distribution of the temperature of the substrate W placed on the placement surface 2a of the rotary table 2, the thermal conductivity adjuster 90 adjusts the in-plane distribution of the thermal conductivity on the lower surface side of the substrate W placed on the placement surface 2a, that is, in the gap between the rotary table 2 and the substrate W. For example, with the substrate W placed on the placement surface 2a and the substrate W being heated by the heater unit 7, the thermal conductivity adjuster 90 adjusts the in-plane distribution of the thermal conductivity in the gap between the rotary table 2 and the substrate W based on the in-plane distribution of the temperature of the substrate W placed on the placement surface 2a. The thermal conductivity adjuster 90 is provided corresponding to each of the six substrates W placed on the rotary table 2. Hereinafter, the thermal conductivity adjuster 90 provided corresponding to one of the six substrates W will be described, but the same may apply to the thermal conductivity adjusters 90 provided corresponding to each of the remaining five substrates W.

[0037] As shown in FIG. 7, the thermal conductivity adjuster 90 includes suction grooves 91a, 91b, 91c, suction holes 92a, 92b, 92c, suction channels 93a, 93b, 93c, on-off valves 94a, 94b, 94c, first ballast channels 95a, 95b, 95c, first ballast sources 96a, 96b, 96c, on-off valves 97a, 97b, 97c, pressure control valves 98a, 98b, 98c, and an exhaust device 99.

[0038] The suction grooves 91a, 91b, 91c are provided on the placement surface 2a formed on the upper surface of the rotary table 2. The suction grooves 91a, 91b, 91c are provided on concentric circles centered on the central axis C1 of the placement surface 2a. The suction grooves 91a, 91b, 91c are provided in this order from the central axis C1 of the placement surface 2a toward the outer peripheral side of the recess 24.

[0039] The suction holes 92a, 92b, and 92c are provided inside the rotary table 2. Each of the suction holes 92a, 92b, and 92c extends along the thickness direction of the rotary table 2 and penetrates the rotary table 2. The upper end of the suction hole 92a communicates with the suction groove 91a. For example, two suction holes 92a are provided along the circumferential direction of the recess 24. The two suction holes 92a are provided on the same circumference centered on the central axis C1 of the mounting surface 2a. The upper end of the suction hole 92b communicates with the suction groove 91b. For example, two suction holes 92b are provided along the circumferential direction of the recess 24. The two suction holes 92b are provided on the same circumference centered on the central axis C1 of the mounting surface 2a. The upper end of the suction hole 92c communicates with the suction groove 91c. For example, two suction holes 92c are provided along the circumferential direction of the recess 24. The two suction holes 92c are provided on the same circumference centered on the central axis C1 of the mounting surface 2a. Each of the suction holes 92a, 92b, and 92c may be one, or may be three or more.

[0040] The suction flow path 93a connects the suction hole 92a and the exhaust device 99. The suction flow path 93b connects the suction hole 92b and the exhaust device 99. The suction flow path 93c connects the suction hole 92c and the exhaust device 99.

[0041] The on-off valve 94a is provided in the suction flow path 93a. The on-off valve 94a is a valve that switches on and off the discharge of fluid from the suction hole 92a to the exhaust device 99. In the open state, the on-off valve 94a allows fluid to flow from the suction hole 92a to the exhaust device 99, and in the closed state, it does not allow fluid to flow from the suction hole 92a to the exhaust device 99.

[0042] The on-off valve 94b is provided in the suction flow path 93b. The on-off valve 94b is a valve that switches on and off the discharge of fluid from the suction hole 92b to the exhaust device 99. In the open state, the on-off valve 94b allows fluid to flow from the suction hole 92b to the exhaust device 99, and in the closed state, it does not allow fluid to flow from the suction hole 92b to the exhaust device 99.

[0043] The on-off valve 94c is provided in the suction channel 93c. The on-off valve 94c is a valve that switches the on and off of the discharge of fluid from the suction hole 92c to the exhaust device 99. In the open state, the on-off valve 94c allows fluid to flow from the suction hole 92c to the exhaust device 99, and in the closed state, it does not allow fluid to flow from the suction hole 92c to the exhaust device 99.

[0044] The first ballast channel 95a merges into the suction channel 93a downstream of the on-off valve 94a. In the first ballast channel 95a, a first ballast source 96a, an on-off valve 97a, and a pressure control valve 98a are provided in order from the upstream. The first ballast source 96a is a supply source of the first ballast gas. The first ballast gas is, for example, nitrogen gas. The first ballast gas may be argon gas. The on-off valve 97a is a valve that switches the on and off of the supply of the first ballast gas to the suction channel 93a. In the open state, the on-off valve 97a allows the first ballast gas to flow from the first ballast source 96a to the suction channel 93a, and in the closed state, it does not allow the first ballast gas to flow from the first ballast source 96a to the suction channel 93a. The pressure control valve 98a controls the pressure of the suction channel 93a by adjusting the flow rate Fa of the first ballast gas supplied from the first ballast source 96a to the suction channel 93a.

[0045] The first ballast channel 95b merges into the suction channel 93b downstream of the on-off valve 94b. In the first ballast channel 95b, a first ballast source 96b, an on-off valve 97b, and a pressure control valve 98b are provided in order from the upstream. The first ballast source 96b is a supply source of the first ballast gas. The on-off valve 97b is a valve that switches the on and off of the supply of the first ballast gas to the suction channel 93b. In the open state, the on-off valve 97b allows the first ballast gas to flow from the first ballast source 96b to the suction channel 93b, and in the closed state, it does not allow the first ballast gas to flow from the first ballast source 96b to the suction channel 93b. The pressure control valve 98b controls the pressure of the suction channel 93b by adjusting the flow rate Fb of the first ballast gas supplied from the first ballast source 96b to the suction channel 93b.

[0046] The first ballast channel 95c merges into the suction channel 93c downstream of the on-off valve 94c. In the first ballast channel 95c, a first ballast source 96c, an on-off valve 97c, and a pressure control valve 98c are provided in order from the upstream. The first ballast source 96c is a supply source of the first ballast gas. The on-off valve 97c is a valve that switches the on and off of the supply of the first ballast gas to the suction channel 93c. In the open state, the on-off valve 97c allows the first ballast gas to flow from the first ballast source 96c to the suction channel 93c, and in the closed state, it does not allow the first ballast gas to flow from the first ballast source 96c to the suction channel 93c. The pressure control valve 98c controls the pressure in the suction channel 93c by adjusting the flow rate Fc of the first ballast gas supplied from the first ballast source 96c to the suction channel 93c.

[0047] The exhaust device 99 is connected to the suction channels 93a, 93b, and 93c. The exhaust device 99 discharges the fluid in the gap between the rotary table 2 and the substrate W through the suction channel 93a, the suction hole 92a, and the suction groove 91a. The exhaust device 99 discharges the fluid in the gap between the rotary table 2 and the substrate W through the suction channel 93b, the suction hole 92b, and the suction groove 91b. The exhaust device 99 discharges the fluid in the gap between the rotary table 2 and the substrate W through the suction channel 93c, the suction hole 92c, and the suction groove 91c. As a result, the pressure on the lower surface side of the substrate W placed on the mounting surface 2a, that is, the pressure in the gap between the rotary table 2 and the substrate W, becomes lower than the pressure on the upper surface side of the substrate W placed on the mounting surface 2a. The exhaust device 99 includes, for example, a vacuum pump.

[0048] Referring to FIGS. 9 and 10, a method for the heat conductivity adjustment unit 90 to adjust the in-plane distribution of the substrate temperature will be described. FIG. 9 is a diagram showing the method for adjusting the in-plane distribution of the substrate temperature. In FIG. 9(a), the horizontal axis represents the in-plane position of the substrate W, and the vertical axis represents the temperature of the substrate W. In FIG. 9(b), the horizontal axis represents the in-plane position of the substrate W, and the vertical axis represents the pressure of the gap between the rotary table 2 and the substrate W. In FIG. 9(c), the horizontal axis represents the in-plane position of the substrate W, and the vertical axis represents the heat conductivity of the gap between the rotary table 2 and the substrate W. In FIG. 9(d), the horizontal axis represents the in-plane position of the substrate W, and the vertical axis represents the substrate temperature. FIG. 10 is a diagram showing the relationship between the pressure and the heat conductivity, and is a double logarithmic graph with the logarithm of the pressure on the horizontal axis and the logarithm of the heat conductivity on the vertical axis.

[0049] As shown in FIG. 9(a), consider the case where the temperature at the center of the substrate W is higher than the temperature at the end of the substrate W in the in-plane distribution. In this case, the heat conductivity adjustment unit 90 controls the pressure control valves 98a, 98b, 98c such that the magnitude relationship of the flow rates Fa, Fb, Fc of the first ballast gas supplied to the suction channels 93a, 93b, 93c is Fa < Fb < Fc. As a result, as shown in FIG. 9(b), the pressure of the gap at the end of the substrate W becomes higher than the pressure of the gap at the center of the substrate W.

[0050] In the gap between the rotary table 2 and the substrate W, as shown in FIG. 10, the pressure and the heat conductivity are proportional. This is because the gas in the gap between the rotary table 2 and the substrate W is in molecular flow or transitional flow. As a result, as shown in FIG. 9(c), the heat conductivity of the gap at the end of the substrate W becomes higher than the heat conductivity of the gap at the center of the substrate W. Therefore, heat is more easily transferred from the rotary table 2 to the substrate W at the end of the substrate W than at the center of the substrate W. As a result, as shown in FIG. 9(d), the in-plane distribution is adjusted such that the temperature at the center of the substrate W is equal to the temperature at the end of the substrate W.

[0051] Referring to FIG. 11, the heat conductivity adjusting unit 90A according to the modified example will be described. FIG. 11 is a cross-sectional view showing the heat conductivity adjusting unit 90A according to the modified example. The heat conductivity adjusting unit 90A is different from the heat conductivity adjusting unit 90 in a configuration that can change the types of the ballast gases supplied to the suction channels 93a, 93b, and 93c. Other configurations may be the same as those of the heat conductivity adjusting unit 90. Hereinafter, the description will focus on the configurations different from those of the heat conductivity adjusting unit 90.

[0052] As shown in FIG. 11, in addition to the configuration of the heat conductivity adjusting unit 90, the heat conductivity adjusting unit 90A includes second ballast channels 191a, 191b, and 191c, second ballast sources 192a, 192b, and 192c, and on-off valves 193a, 193b, and 193c.

[0053] The second ballast flow path 191a merges into the first ballast flow path 95a between the on-off valve 97a and the pressure control valve 98a. In the second ballast flow path 191a, a second ballast source 192a and an on-off valve 193a are provided in order from the upstream. The second ballast source 192a is a supply source of the second ballast gas. The second ballast gas is a gas having a higher thermal conductivity than the first ballast gas. The second ballast gas may be, for example, hydrogen gas. The second ballast gas may be helium gas. Hydrogen gas and helium gas are gases having a higher thermal conductivity than nitrogen gas and argon gas. The on-off valve 193a is a valve that switches on and off the supply of the second ballast gas to the suction flow path 93a. In the open state, the on-off valve 193a allows the second ballast gas to flow from the second ballast source 192a to the suction flow path 93a, and in the closed state, the on-off valve 193a does not allow the second ballast gas to flow from the second ballast source 192a to the suction flow path 93a. The thermal conductivity adjustment unit 90A changes the type of the ballast gas supplied to the suction flow path 93a by switching the on-off valve 97a and the on-off valve 193a between the open state and the closed state. The thermal conductivity adjustment unit 90A supplies the first ballast gas to the suction flow path 93a by setting the on-off valve 97a to the open state and the on-off valve 193a to the closed state. The thermal conductivity adjustment unit 90A supplies the second ballast gas to the suction flow path 93a by setting the on-off valve 97a to the closed state and the on-off valve 193a to the open state. The thermal conductivity adjustment unit 90A supplies the first ballast gas and the second ballast gas to the suction flow path 93a by setting the on-off valve 97a and the on-off valve 193a to the open state.

[0054] The second ballast flow path 191b merges into the first ballast flow path 95b between the on-off valve 97b and the pressure control valve 98b. In the second ballast flow path 191b, a second ballast source 192b and an on-off valve 193b are provided in order from the upstream. The second ballast source 192b is a supply source of the second ballast gas. The on-off valve 193b is a valve that switches on and off the supply of the second ballast gas to the suction flow path 93b. When the on-off valve 193b is in the open state, the second ballast gas flows from the second ballast source 192b to the suction flow path 93b, and when it is in the closed state, the second ballast gas does not flow from the second ballast source 192b to the suction flow path 93b. The thermal conductivity adjustment unit 90A changes the type of the ballast gas supplied to the suction flow path 93b by switching the on-off valve 97b and the on-off valve 193b between the open state and the closed state. The thermal conductivity adjustment unit 90A supplies the first ballast gas to the suction flow path 93b by setting the on-off valve 97b to the open state and the on-off valve 193b to the closed state. The thermal conductivity adjustment unit 90A supplies the second ballast gas to the suction flow path 93b by setting the on-off valve 97b to the closed state and the on-off valve 193b to the open state. The thermal conductivity adjustment unit 90A supplies the first ballast gas and the second ballast gas to the suction flow path 93b by setting the on-off valve 97b and the on-off valve 193b to the open state.

[0055] The second ballast flow path 191c merges into the first ballast flow path 95c between the on-off valve 97c and the pressure control valve 98c. In the second ballast flow path 191c, a second ballast source 192c and an on-off valve 193c are provided in order from the upstream. The second ballast source 192c is a supply source of the second ballast gas. The on-off valve 193c is a valve that switches on and off the supply of the second ballast gas to the suction flow path 93c. When the on-off valve 193c is in the open state, the second ballast gas flows from the second ballast source 192c to the suction flow path 93c, and when it is in the closed state, the second ballast gas does not flow from the second ballast source 192c to the suction flow path 93c. The thermal conductivity adjustment unit 90A changes the type of the ballast gas supplied to the suction flow path 93c by switching the on-off valve 97c and the on-off valve 193c between the open state and the closed state. The thermal conductivity adjustment unit 90A supplies the first ballast gas to the suction flow path 93c by setting the on-off valve 97c to the open state and the on-off valve 193c to the closed state. The thermal conductivity adjustment unit 90A supplies the second ballast gas to the suction flow path 93c by setting the on-off valve 97c to the closed state and the on-off valve 193c to the open state. The thermal conductivity adjustment unit 90A supplies the first ballast gas and the second ballast gas to the suction flow path 93c by setting the on-off valve 97c and the on-off valve 193c to the open state.

[0056] Referring to FIG. 12, a method in which the thermal conductivity adjustment unit 90A adjusts the in-plane distribution of the substrate temperature will be described. FIG. 12 is a diagram showing a method of adjusting the in-plane distribution of the substrate temperature. In FIG. 12(a), the horizontal axis indicates the in-plane position of the substrate W, and the vertical axis indicates the temperature of the substrate W. In FIG. 12(b), the horizontal axis indicates the in-plane position of the substrate W, and the vertical axis indicates the thermal conductivity of the gap between the rotary table 2 and the substrate W. In FIG. 10(c), the horizontal axis indicates the in-plane position of the substrate W, and the vertical axis indicates the substrate temperature.

[0057] As shown in FIG. 12(a), consider a case where the temperature distribution in the plane of the substrate W is such that the temperature at the center of the substrate W is higher than the temperature at the edge of the substrate W. In this case, the thermal conductivity adjustment unit 90A controls the on-off valves 97a, 97b, 97c, 193a, 193b, 193c so that the first ballast gas is supplied to the suction channels 93a and 93b, and the second ballast gas is supplied to the suction channel 93c. Specifically, the on-off valves 97a, 97b, 193c are set to the open state, and the on-off valves 193a, 193b, 97c are set to the closed state. As a result, as shown in FIG. 12(b), the thermal conductivity of the gap at the edge of the substrate W becomes higher than the thermal conductivity of the gap at the center of the substrate W. For this reason, heat is more easily transferred from the rotary table 2 to the substrate W at the edge of the substrate W than at the center of the substrate W. As a result, as shown in FIG. 12(c), the temperature distribution in the plane is adjusted so that the temperature at the center of the substrate W is equal to the temperature at the edge of the substrate W.

[0058] As described above, the substrate processing apparatus according to the embodiment includes a thermal conductivity adjustment unit 90 that adjusts the in-plane distribution of the thermal conductivity of the gap between the rotary table 2 and the substrate W. In this case, the ease of heat transfer from the rotary table 2 to the substrate W is controlled, and the in-plane distribution of the substrate temperature can be adjusted.

[0059] The embodiments disclosed this time should be considered to be illustrative in all respects and not restrictive. The above embodiments may be omitted, replaced, or changed in various forms without departing from the scope and spirit of the appended claims.

[0060] In the above embodiment, the case where the thermal conductivity adjustment units 90 and 90A have three suction channels 93a, 93b, and 93c has been described, but the present disclosure is not limited to this. For example, the thermal conductivity adjustment units 90 and 90A may have one or two suction channels, or may have four or more suction channels.

[0061] In the above-described embodiment, the case where the thermal conductivity adjustment unit 90A is configured to be able to supply two types of ballast gas to each of the suction channels 93a, 93b, and 93c has been described. However, the present disclosure is not limited thereto. For example, the thermal conductivity adjustment unit 90A may be configured to be able to supply three or more types of ballast gas to each of the suction channels 93a, 93b, and 93c.

[0062] In the above-described embodiment, the case where the thermal conductivity adjustment unit 90A has the pressure control valves 98a, 98b, and 98c has been described. However, the present disclosure is not limited thereto. For example, the thermal conductivity adjustment unit 90A may not have the pressure control valves 98a, 98b, and 98c.

Explanation of Reference Numerals

[0063] 1 Vacuum chamber 2 Rotating table 2a Placement surface 7 Heater unit 90 Thermal conductivity adjustment unit W Substrate

Claims

1. A vacuum chamber, a rotary table provided in the vacuum chamber and having a placement surface for placing a substrate formed on an upper surface thereof, a heating unit provided below the rotary table for heating the substrate by radiation, a thermal conductivity adjuster for adjusting an in-plane distribution of a thermal conductivity of a gap between the rotary table and the substrate, A substrate processing apparatus comprising the above.

2. The thermal conductivity adjuster has a first suction groove provided on the placement surface, a first suction hole communicating with the first suction groove, and a first suction flow path connected to the first suction hole and supplied with a ballast gas, and the thermal conductivity adjuster adjusts the in-plane distribution of the thermal conductivity of the gap by controlling a flow rate of the ballast gas supplied to the first suction flow path. The substrate processing apparatus according to claim 1.

3. The thermal conductivity adjuster has a second suction groove provided at a position different from the first suction groove on the placement surface, a second suction hole communicating with the second suction groove, and a second suction flow path connected to the second suction hole and supplied with the ballast gas, and the thermal conductivity adjuster adjusts the in-plane distribution of the thermal conductivity of the gap by controlling a flow rate of the ballast gas supplied to the first suction flow path and a flow rate of the ballast gas supplied to the second suction flow path. The substrate processing apparatus according to claim 2.

4. The thermal conductivity adjuster has a first suction groove provided on the placement surface, a first suction hole communicating with the first suction groove, and a first suction flow path connected to the first suction hole and supplied with a ballast gas, and the thermal conductivity adjuster adjusts the in-plane distribution of the thermal conductivity of the gap by changing a type of the ballast gas supplied to the first suction flow path. The substrate processing apparatus according to claim 1.

5. The thermal conductivity adjuster has a second suction groove provided at a position different from the first suction groove on the placement surface, a second suction hole communicating with the second suction groove, and a second suction flow path connected to the second suction hole and supplied with the ballast gas, and the thermal conductivity adjuster adjusts the in-plane distribution of the thermal conductivity of the gap by changing at least one type of the ballast gas supplied to the first suction flow path and the ballast gas supplied to the second suction flow path. The substrate processing apparatus according to claim 4.

6. The first suction groove and the second suction groove are provided on concentric circles centered on a central axis of the placement surface. The substrate processing apparatus according to claim 3 or 5.

7. The pressure in the gap is lower than the pressure on the upper surface side of the substrate. The substrate processing apparatus according to any one of claims 1 to 5.

8. The center of the placement surface is provided at a position horizontally displaced with respect to the rotation axis of the rotary table. The substrate processing apparatus according to any one of claims 1 to 5.

9. A plurality of the placement surfaces are provided along the circumferential direction of the rotary table. The substrate processing apparatus according to claim 8.

10. The heating unit includes a plurality of heaters. The plurality of heaters are provided on concentric circles centered on the rotation axis of the rotary table. The substrate processing apparatus according to any one of claims 1 to 5.

11. The rotary table is formed of quartz. The substrate processing apparatus according to any one of claims 1 to 5.

12. The thermal conductivity adjustment unit adjusts the in-plane distribution of the thermal conductivity of the gap based on the in-plane distribution of the temperature of the substrate placed on the placement surface. The substrate processing apparatus according to any one of claims 1 to 5.

13. Placing a substrate on a placement surface formed on the upper surface of a rotary table provided in a vacuum chamber; Rotating the rotary table with the substrate placed on the placement surface; Heating the substrate by radiation with a heating unit provided below the rotary table; Adjusting the in-plane distribution of the thermal conductivity of the gap between the rotary table and the substrate; A substrate processing method having the above steps.

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