Heat treatment apparatus, heat treatment method, and storage medium

Abstract

To suppress contamination of a substrate caused by a sublimate generated from a coating of a resist on the substrate and improve substrate intra-plane uniformity of thermal processing.SOLUTION: A thermal processing device thermally processes a substrate in which a coating of a resist is formed and exposure processing is applied to the coating. The substrate processing device comprises a hot plate which supports and heats the substrate and a chamber in which the hot plate is stored, and further comprises a gas discharge unit which is provided in a ceiling part and discharges gas for processing from an upper side toward the substrate on the hot plate, a gaseous matter supply unit which supplies gaseous matter toward the substrate on the hot plate, a center exhaust unit which exhausts the inside of a processing space in the chamber, a periphery exhaust unit which exhausts the inside of the processing space, and a control unit. The discharge by the gas discharge unit, the supply of the gaseous matter by the gaseous matter supply unit, and the exhaustion by the periphery exhaust unit are continued, and control is performed to strengthen the exhaustion by the center exhaust unit in the middle of the thermal processing. The gaseous matter supply unit includes a gaseous matter passage which is provided so as to enclose a side face of the hot plate, and a rectification member for moving the gaseous matter which rises along the gaseous matter passage toward the substrate on the hot plate.SELECTED DRAWING: Figure 4

Description

[Technical Field]

[0001] The present disclosure relates to a heat treatment apparatus, a heat treatment method, and a storage medium. [Background technology]

[0002] Patent Document 1 discloses a method for patterning a substrate with radiation. The method includes irradiating a coated substrate along a selected pattern to form an irradiated structure having regions of an irradiated coating and regions of an irradiated coating. The coated substrate includes a coating comprising a metal oxo-hydroxo network with organic ligands via metal-carbon and / or metal carboxylate bonds. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Special Publication No. 2016-530565 Summary of the Invention [Problem to be solved by the invention]

[0004] The technology according to the present disclosure is capable of suppressing contamination of a substrate caused by sublimation products generated from a resist coating on the substrate. do. [Means for solving the problem]

[0005] One aspect of the present disclosure is a heat treatment apparatus for heat treating a substrate on which a resist film is formed, the heat treatment apparatus comprising: a heat plate for supporting and heating the substrate; and a chamber for accommodating the heat plate, the chamber defining a processing space below which the heat treatment is performed and having a ceiling portion facing the substrate on the heat plate; a gas discharge unit provided in the ceiling portion and configured to discharge a processing gas from above toward the substrate on the hot plate; A gas is blown from a side of the substrate on the hot plate and a lower part of the processing space toward the substrate on the hot plate. but supply configured to be a gas supply unit; a central exhaust section that exhausts air from the processing space in the chamber from a position in the ceiling section that is close to the center of the substrate on the hot plate in a top view; In the ceiling portion, a front The central exhaust section and the gas discharge section than on the hot plate The apparatus further includes an exhaust unit that exhausts the inside of the processing space from the peripheral edge side of the substrate, and a control unit, wherein the control unit controls the following during the heat treatment: Discharge by the gas discharge unit; Supply of gas by the gas supply unit and the central exhaust section and the above periphery Exhaust from the exhaust section and, To ensure that In addition, the exhaust from the central exhaust section becomes stronger during the heat treatment. The gas supply unit has a gas flow path provided so as to surround the side surface of the hot plate, and a rectifying member that directs the gas that rises along the gas flow path toward the substrate on the hot plate. The gas flow path is connected to a buffer space below the hot plate in the chamber, and the buffer space has a volume larger than that of the processing space. . [Effects of the Invention]

[0006] According to the present disclosure, it is possible to suppress contamination of the substrate due to sublimation products generated from the resist coating on the substrate, and to improve the uniformity of the heat treatment within the substrate surface. [Brief explanation of the drawings]

[0007] [Figure 1] 1 is an explanatory diagram showing an outline of the internal configuration of a coating and developing system as a substrate processing system including a heat treatment apparatus according to an embodiment of the present invention; [Figure 2] FIG. 2 is a diagram showing an outline of the internal configuration of the coating and developing system from the front side. [Figure 3] FIG. 2 is a diagram showing an outline of the internal configuration of the coating and developing system on the rear side. [Figure 4] FIG. 1 is a longitudinal sectional view schematically illustrating the outline of the configuration of a heat treatment apparatus used in PEB treatment. [Figure 5] FIG. 2 is a bottom view schematically illustrating the configuration of the upper chamber. [Figure 6] 1A and 1B are diagrams illustrating states of a heat treatment apparatus during wafer processing performed using the heat treatment apparatus; [Figure 7] 1A and 1B are diagrams illustrating states of a heat treatment apparatus during wafer processing performed using the heat treatment apparatus; [Figure 8] 1A and 1B are diagrams illustrating states of a heat treatment apparatus during wafer processing performed using the heat treatment apparatus; [Figure 9]10A and 10B are diagrams illustrating the effects of the heat treatment apparatus according to the present embodiment. [Figure 10] FIG. 10 is a diagram showing the results of a confirmation test. [Figure 11] FIG. 10 is a diagram showing the results of a confirmation test. [Figure 12] FIG. 10 is a diagram showing the results of a confirmation test. [Figure 13] FIG. 10 is a diagram showing the results of a confirmation test. [Figure 14] FIG. 10 is a diagram showing the results of a confirmation test. DETAILED DESCRIPTION OF THE INVENTION

[0008] In the manufacturing process of semiconductor devices, etc., predetermined processes are performed to form a resist pattern on a semiconductor wafer (hereinafter referred to as "wafer"). The predetermined processes include, for example, a resist coating process in which a resist solution is supplied onto the wafer to form a resist film, an exposure process in which the film is exposed to light, a PEB (Post Exposure Bake) process in which heating is performed after exposure to promote a chemical reaction in the film, and a development process in which the exposed film is developed.

[0009] PEB processing is performed, for example, while exhausting the atmosphere around the substrate. In this case, depending on the type of exhaust, the dimensions of the resist pattern may vary within the surface. Furthermore, in the case of a resist that generates sublimates, such as a metal-containing resist, depending on the type of exhaust, the bevel portion or backside of the substrate may be contaminated by the sublimates.

[0010] Therefore, the technology according to the present disclosure suppresses contamination of the substrate due to sublimation products generated from the resist coating on the substrate, and improves the uniformity of the heat treatment within the substrate surface.

[0011] Hereinafter, a heat treatment apparatus and a heat treatment method according to the present embodiment will be described with reference to the drawings. In this specification and the drawings, elements having substantially the same functional configurations are designated by the same reference numerals, and redundant description will be omitted.

[0012] <Coating and developing system> Fig. 1 is an explanatory diagram showing an outline of the internal configuration of a coating and developing system as a substrate processing system including a heat treatment apparatus according to this embodiment. Fig. 2 and Fig. 3 are diagrams showing an outline of the internal configuration of the coating and developing system from the front side and rear side, respectively.

[0013] The coating and developing system 1 uses a resist to form a resist pattern on a wafer W as a substrate. The resist used is a resist that generates a sublimation product, such as a metal-containing resist. The metal contained in the metal-containing resist is arbitrary, but is, for example, tin.

[0014] 1 to 3, the coating and developing system 1 includes a cassette station 2 into which a cassette C, which is a container capable of accommodating a plurality of wafers, is carried in and out, and a processing station 3 equipped with a plurality of various processing devices that perform predetermined processes such as resist coating. The coating and developing system 1 has a configuration in which the cassette station 2, the processing station 3, and an interface station 5 that transfers the wafer W between them and an exposure device 4 adjacent to the processing station 3 are integrally connected.

[0015] The cassette station 2 is divided into, for example, a cassette loading / unloading section 10 and a wafer transport section 11. For example, the cassette loading / unloading section 10 is provided at the end of the coating and developing system 1 on the negative Y-direction side (left direction in FIG. 1). The cassette loading / unloading section 10 is provided with a cassette mounting table 12. A plurality of, for example, four mounting plates 13 are provided on the cassette mounting table 12. The mounting plates 13 are arranged in a row in the horizontal X-direction (up and down direction in FIG. 1). The cassettes C can be placed on these mounting plates 13 when they are loaded or unloaded from the coating and developing system 1.

[0016] The wafer transfer section 11 is provided with a transfer device 20 that transfers wafers W. The transfer device 20 is configured to be movable on a transfer path 21 that extends in the X direction. The transfer device 20 is also movable in the vertical direction and around the vertical axis (the θ direction), and can transfer wafers W between cassettes C on each mounting plate 13 and a transfer device in a third block G3 of the processing station 3, which will be described later.

[0017] The processing station 3 is provided with multiple blocks, for example, four blocks G1, G2, G3, and G4, each equipped with various devices. For example, a first block G1 is provided on the front side of the processing station 3 (the negative X-direction side in FIG. 1), and a second block G2 is provided on the back side of the processing station 3 (the positive X-direction side in FIG. 1). A third block G3 is provided on the cassette station 2 side of the processing station 3 (the negative Y-direction side in FIG. 1), and a fourth block G4 is provided on the interface station 5 side of the processing station 3 (the positive Y-direction side in FIG. 1).

[0018] As shown in FIG. 2, the first block G1 has a plurality of liquid processing apparatuses, such as a developing apparatus 30, a lower anti-reflection coating forming apparatus 31, a resist coating apparatus 32, and an upper anti-reflection coating forming apparatus 33, arranged in this order from bottom to top. The developing apparatus 30 performs a developing process on the wafer W. Specifically, the developing apparatus 30 performs a developing process on the metal-containing resist film on the wafer W that has been subjected to PEB processing. The lower anti-reflection coating forming apparatus 31 forms an anti-reflection coating (hereinafter referred to as a "lower anti-reflection coating") below the metal-containing resist film on the wafer W. The resist coating apparatus 32 applies a metal-containing resist to the wafer W to form a metal-containing resist coating, i.e., a metal-containing resist film. The upper anti-reflection coating forming apparatus 33 forms an anti-reflection coating (hereinafter referred to as an "upper anti-reflection coating") above the metal-containing resist film on the wafer W.

[0019] For example, three developing treatment devices 30, three lower anti-reflection coating forming devices 31, three resist coating devices 32, and three upper anti-reflection coating forming devices 33 are arranged horizontally. The number and arrangement of these developing treatment devices 30, three lower anti-reflection coating forming devices 31, three resist coating devices 32, and three upper anti-reflection coating forming devices 33 can be selected arbitrarily.

[0020] In the developing treatment device 30, the lower anti-reflection coating forming device 31, the resist coating device 32, and the upper anti-reflection coating forming device 33, a predetermined processing liquid is applied onto the wafer W by, for example, a spin coating method. In the spin coating method, the processing liquid is discharged onto the wafer W from, for example, a discharge nozzle, and the wafer W is rotated to diffuse the processing liquid over the surface of the wafer W.

[0021] 3, the second block G2 is provided with heat treatment devices 40 arranged in a vertical and horizontal direction for heat treatment of wafers W. The number and arrangement of the heat treatment devices 40 can be selected as desired. The heat treatment devices 40 perform a pre-baking process (hereinafter referred to as a "PAB process") for heating wafers W after a resist coating process, a PEB process for heating wafers W after an exposure process, a post-baking process (hereinafter referred to as a "POST process") for heating wafers W after a development process, and the like.

[0022] For example, in the third block G3, a plurality of transfer devices 50, 51, 52, 53, 54, 55, and 56 are provided in this order from the bottom. In addition, in the fourth block G4, a plurality of transfer devices 60, 61, and 62 and a back surface cleaning device 63 that cleans the back surface of the wafer W are provided in this order from the bottom.

[0023] 1, a wafer transfer area D is formed in an area surrounded by the first block G1 to the fourth block G4. In the wafer transfer area D, a transfer device 70 serving as a substrate transfer device for transferring, for example, a wafer W is disposed.

[0024] The transfer device 70 has a transfer arm 70a that is movable in, for example, the Y direction, the θ direction, and the up-down direction. The transfer device 70 moves the transfer arm 70a holding the wafer W within the wafer transfer region D, and can transfer the wafer W to a predetermined device in the surrounding first block G1, second block G2, third block G3, and fourth block G4. For example, as shown in FIG. 3, a plurality of transfer devices 70 are arranged one above the other, and can transfer the wafer W to a predetermined device at approximately the same height in each of the blocks G1 to G4.

[0025] In addition, the wafer transfer region D is provided with a shuttle transfer device 80 that transfers the wafer W linearly between the third block G3 and the fourth block G4.

[0026] The shuttle transfer device 80 moves the supported wafer W linearly in the Y direction, and can transfer the wafer W between the transfer device 52 in the third block G3 and the transfer device 62 in the fourth block G4, which are at approximately the same height.

[0027] 1, a transfer device 90 is provided on the positive X-direction side of the third block G3. The transfer device 90 has a transfer arm 90a that is movable, for example, in the θ direction and in the vertical direction. The transfer device 90 moves the transfer arm 90a holding the wafer W up and down, and can transfer the wafer W to each delivery device in the third block G3.

[0028] The interface station 5 is provided with a transfer device 100 and a delivery device 101. The transfer device 100 has a transfer arm 100a that is movable, for example, in the θ direction and in the vertical direction. The transfer device 100 holds a wafer W on the transfer arm 100a and can transfer the wafer W between each delivery device in the fourth block G4, the delivery device 101, and the exposure device 4.

[0029] The coating and developing system 1 described above is provided with a control unit 200 as shown in FIG. 1. The control unit 200 is a computer equipped with a processor such as a CPU, a memory, and the like, and has a program storage unit (not shown). The program storage unit stores a program that controls the operation of the drive systems of the various processing devices and transport devices described above, and controls the wafer processing described below. The program may be recorded on a computer-readable non-transitory storage medium H and installed from the storage medium H into the control unit 200. The storage medium H may be either temporary or non-transitory. Some or all of the program may be realized by dedicated hardware (circuit board).

[0030] <Wafer processing using coating and developing system 1> Next, a description will be given of an example of wafer processing using the coating and developing system 1. The following processing is performed under the control of the control unit 200.

[0031] First, a cassette C containing a plurality of wafers W is carried into the cassette station 2 of the coating and developing system 1 and placed on the placement plate 13. Thereafter, the transfer device 20 sequentially removes each wafer W from the cassette C and transfers them to the delivery device 53 in the third block G3 of the processing station 3.

[0032] Next, the wafer W is transferred by the transfer device 70 to the heat treatment device 40 in the second block G2, where it is subjected to temperature adjustment processing. Thereafter, the wafer W is transferred by the transfer device 70 to, for example, the bottom anti-reflection coating forming device 31 in the first block G1, where a bottom anti-reflection coating is formed on the wafer W. Thereafter, the wafer W is transferred to the heat treatment device 40 in the second block G2, where it is subjected to heat treatment. Thereafter, the wafer W is returned to the delivery device 53 in the third block G3.

[0033] Next, the wafer W is transferred by the transfer device 70 to the resist coating device 32, where a metal-containing resist film is formed on the wafer W. Thereafter, the wafer W is transferred by the transfer device 70 to the heat treatment device 40, where it is subjected to PAB treatment. Thereafter, the wafer W is transferred by the transfer device 70 to the delivery device 55 in the third block G3.

[0034] Next, the wafer W is transferred by the transfer device 70 to the top anti-reflection coating forming device 33, where a top anti-reflection coating is formed on the wafer W. Thereafter, the wafer W is transferred by the transfer device 70 to the heat treatment device 40, where it is heated and its temperature is adjusted.

[0035] Thereafter, the wafer W is transferred by the transfer device 70 to the delivery device 56 in the third block G3.

[0036] Next, the wafer W is transferred to the transfer device 52 by the transfer device 90, and then transferred to the transfer device 62 in the fourth block G4 by the shuttle transfer device 80. Thereafter, the wafer W is transferred to the back surface cleaning device 63 by the transfer device 100, where the back surface is cleaned. Next, the wafer W is transferred to the exposure device 4 by the transfer device 100 in the interface station 5, where it is exposed to EUV light in a predetermined pattern.

[0037] Next, the wafer W is transferred to the delivery device 60 in the fourth block G4 by the transfer device 100. Thereafter, the wafer W is transferred to the heat treatment device 40 and subjected to the PEB treatment.

[0038] Next, the wafer W is transferred by the transfer device 70 to the developing treatment device 30 and developed. After the development is completed, the wafer W is transferred by the transfer device 90 to the heat treatment device 40 and subjected to POST treatment.

[0039] Thereafter, the wafer W is transferred by the transfer device 70 to the delivery device 50 in the third block G3, and then transferred by the transfer device 20 in the cassette station 2 to the cassette C on the predetermined mounting plate 13. In this way, a series of photolithography steps is completed.

[0040] <Heat treatment equipment> Next, a description will be given of the heat treatment apparatus 40 used for PEB processing. Fig. 4 is a vertical cross-sectional view showing a schematic outline of the configuration of the heat treatment apparatus 40 used for PEB processing. Fig. 5 is a bottom view showing a schematic outline of the configuration of an upper chamber 301 described below.

[0041] 4 includes a chamber 300. The chamber 300 includes an upper chamber 301, a lower chamber 302, and a flow straightening member 303. The upper chamber 301 is located on the upper side, and the lower chamber 302 is located on the lower side. The flow straightening member 303 is located between the upper chamber 301 and the lower chamber 302, specifically, between the peripheral edge of the upper chamber 301 and the peripheral edge of the lower chamber 302.

[0042] The upper chamber 301 is configured to be able to move up and down freely. A lifting mechanism (not shown) having a drive source such as a motor for lifting and lowering the upper chamber 301 is controlled by the control unit 200. The upper chamber 301 is formed, for example, in a disk shape. The upper chamber 301 has a ceiling 310. The ceiling 310 forms a processing space K1 below which heat treatment is performed, and is disposed so as to face the wafer W on the heating plate 328. The ceiling 310 is also provided with a shower head 311 as a gas discharge unit.

[0043] The shower head 311 discharges a processing gas from above toward the wafer W on the heating plate 328. The processing gas is, for example, a gas containing moisture, that is, a moisture-containing gas. The shower head 311 has a plurality of outlet holes 312 and a gas distribution space 313 .

[0044] The discharge holes 312 are formed in the lower surface of the shower head 311. For example, as shown in Fig. 5, the discharge holes 312 are arranged approximately uniformly on the lower surface of the shower head 311 in a portion other than the exhaust holes, which will be described later. The plurality of discharge holes 312 includes a first discharge hole located above the peripheral portion of the wafer W on the heat plate 328 and a second discharge hole located above the central portion of the wafer W on the heat plate 328.

[0045] The gas distribution space 313 distributes the processing gas supplied thereto and supplies it to each outlet hole 312. As shown in Fig. 4, a processing gas source 315 that stores the processing gas is connected to the shower head 311 via a gas supply pipe 314. The gas supply pipe 314 is provided with a supply device group 316 that includes valves, flow rate control valves, etc. that control the flow of the processing gas.

[0046] Furthermore, a central exhaust section 317 is provided on the ceiling section 310 of the upper chamber 301. The central exhaust section 317 evacuates the processing space K1 above the hot plate 328 in the chamber 300 from a position on the ceiling section 310 near the center of the wafer W on the hot plate 328 in a top view (from the center position in the illustrated example). The central exhaust section 317 has exhaust holes 318. As shown in FIG. 5, the exhaust holes 318 are provided on the underside of the shower head 311 near the center of the wafer W on the hot plate 328 in a top view (the center position in the illustrated example), and open downward. The central exhaust section 317 evacuates the processing space K1 through the exhaust holes 318. Although not shown, a plurality of exhaust holes 318 may be provided to surround a position directly above the center of the wafer W. In this case, the plurality of exhaust holes 318 are provided, for example, at positions in an area within one-third of the wafer radius from the center of the wafer W when viewed from above, so as not to impair the exhaust action of the central exhaust section 317 described below.

[0047] 4, central exhaust section 317 has central exhaust path 319 formed to extend upward from exhaust hole 318. Exhaust device 321 such as a vacuum pump is connected to central exhaust path 319 via exhaust pipe 320. Exhaust pipe 320 is provided with exhaust equipment group 322 having valves and the like for adjusting the amount of exhaust.

[0048] Furthermore, a peripheral exhaust section 323 is provided on the ceiling section 310 of the upper chamber 301. The peripheral exhaust section 323 exhausts air from the processing space K1 from a portion of the ceiling section 310 closer to the peripheral edge of the wafer W on the hot plate 328 than the central exhaust section 317 in a top view. The peripheral exhaust section 323 has an exhaust port 324. As shown in FIG. 5 , the exhaust port 324 opens downward from the underside of the ceiling section 310 so as to surround the outer periphery of the shower head 311. The exhaust port 324 may be a plurality of exhaust holes arranged along the outer periphery of the shower head 311. The peripheral exhaust section 323 exhausts air from the processing space K1 through the exhaust port 324.

[0049] The exhaust port 324 is provided, for example, between a position where the peripheral edge of the exhaust port 324 overlaps with the peripheral edge of the wafer W on the heating plate 328 in a top view and a position 10 mm inside that position.

[0050] 4 has a peripheral exhaust path extending from an exhaust port 324. An exhaust device 326 such as a vacuum pump is connected to the peripheral exhaust path via an exhaust pipe 325. An exhaust device group 327 having a valve for adjusting the amount of exhaust is provided in the exhaust pipe 325.

[0051] Furthermore, the upper chamber 301 is configured to be able to heat the upper chamber 301. For example, the upper chamber 301 has a built-in heater (not shown) that heats the upper chamber 301. This heater is controlled by the control unit 200, and the upper chamber 301 (specifically, for example, the shower head 311) is adjusted to a predetermined temperature.

[0052] The lower chamber 302 is provided to surround the periphery of a hot plate 328 that supports and heats the wafer W.

[0053] The heating plate 328 has a thick disk shape. The heating plate 328 has, for example, a built-in heater 329. The temperature of the heating plate 328 is controlled by, for example, the control unit 200, and the wafer W placed on the heating plate 328 is heated to a predetermined temperature.

[0054] Furthermore, the hot plate 328 has, for example, a plurality of suction holes 330 for suctioning the wafer W to the hot plate 328. Each suction hole 330 is formed so as to penetrate the hot plate 328 in the thickness direction. Each suction hole 330 is connected to a relay hole 332 of a relay member 331. Each relay hole 332 is connected to an exhaust line 333 that exhausts air for suction.

[0055] The suction holes 330 and the relay holes 332 are connected via a metal member 334 made of metal and a resin pad 335. Specifically, the suction holes 330 and the relay holes 332 are connected via a flow path in the metal member 334 and a flow path in the resin pad 335.

[0056] The metal member 334 is located on the suction hole 330 side, and the resin pad 335 is located on the relay hole 332 side. One end of the metal member 334 is directly connected to the heat plate 328 (specifically, the suction hole 330), and the other end is directly connected to one end of the corresponding resin pad 335. In other words, each resin pad 335 is in communication with the corresponding suction hole 330 and connected to the heat plate 328 via the metal member 334. The other end of the resin pad 335 is directly connected to the relay member 331 (specifically, the relay hole 332).

[0057] The metal member 334 has a large-diameter portion 336 on the resin pad 335 side. The interior of the large-diameter portion 336 has a flow path space 336a with a larger cross-sectional area than the portion of the metal member 334 connected to the hot plate 328, reducing the risk of clogging due to sublimates generated during heat treatment. Furthermore, this flow path space 336a with a large cross-sectional area reduces the heat of the gas sucked from the processing space K1 when the wafer W is adsorbed, allowing it to flow toward the adsorption exhaust line 333. In other words, the risk of deterioration due to high temperatures of the devices constituting the exhaust flow path from the resin pad 335 to the exhaust line 333 can be reduced.

[0058] Also, in the lower chamber 302, for example, three lift pins (not shown) are provided below the heat plate 328 to support and lift the wafer W from below. The lift pins are raised and lowered by a lift mechanism (not shown) having a drive source such as a motor. This lift mechanism is controlled by the control unit 200. In addition, a through hole (not shown) through which the lift pins pass is formed in the center of the heat plate 328. The lift pins can pass through the through hole and protrude from the upper surface of the heat plate.

[0059] Additionally, the lower chamber 302 includes a support ring 337 and a bottom chamber 338 .

[0060] The support ring 337 has a cylindrical shape. The support ring 337 is made of a metal such as stainless steel. The support ring 337 covers the outer surface of the heat plate 328. The support ring 337 is fixed onto the bottom chamber 338.

[0061] The bottom chamber 338 has a cylindrical shape with a bottom. The aforementioned hot plate 328 is supported, for example, on the bottom wall of the bottom chamber 338. Specifically, the hot plate 328 is supported on the bottom wall of the bottom chamber 338 via a support part 339. The support part 339 has, for example, a support pillar 340 whose upper end is connected to the hot plate 328, an annular member 341 that supports the support pillar 340, and a leg member 342 that supports the annular member 341 on the bottom wall of the bottom chamber 338.

[0062] The ring-shaped member 341 is made of metal and is provided with a gap equal to the height of the support pillars 340 from most of the rear surface of the heat plate 328. By positioning the resin pad 335 below the ring-shaped member 341 provided in this manner, the ring-shaped member 341 effectively blocks the heat from the heat plate 328, making the resin pad 335 less likely to be exposed to high temperatures (less likely to be thermally deteriorated).

[0063] Furthermore, the lower chamber 302 has an intake port 343. The intake port 343 takes in gas from the outside of the chamber 300 into the chamber 300. The intake port 343 is formed in, for example, the cylindrical side wall of the bottom chamber 338. The inner circumferential surface of the side wall of the bottom chamber 338 and the inner circumferential surface of the support ring 337 have, for example, the same diameter.

[0064] The chamber 300 also has a gas supply unit 344. The gas supply unit 344 supplies gas toward the wafer W on the heating plate 328 from below the surface (ie, the upper surface) of the wafer W on the heating plate 328.

[0065] The gas supply unit 344 includes a gas flow path 345 provided so as to surround the side surface of the heat plate 328 , and a flow straightening member 303 .

[0066] The gas flow path 345 is, for example, formed by the space between the outer surface of the heat plate 328 and the inner circumferential surface of the support ring 337. Therefore, the gas flow path 345 is formed, for example, in a circular shape in a plan view. Note that the outer surface of the heat plate 328 may be supported by the inner circumferential surface of the side wall of the lower chamber 302 via a support member, and a plurality of through holes penetrating in the vertical direction may be formed in the support member in an annular pattern, and the plurality of through holes may serve as the gas flow path 345.

[0067] The flow straightening member 303 is a member that directs the gas that has risen along the gas flow path 345 toward the wafer W on the heating plate 328 .

[0068] The flow regulating member 303 is formed, for example, in a circular ring shape in a plan view. The inner peripheral lower surface of the rectifying member 303 serves as a guide surface that guides the gas rising along the gas flow path 345 toward the center of the hot plate 328. The inner peripheral end of the lower surface of the rectifying member 303 is located at a height equal to or less than half the height of the processing space K1, that is, the height from the surface of the hot plate 328 on which the wafer W is placed to the lower surface of the shower head 311, on which the discharge holes 312 are formed and which faces the wafer W on the hot plate 328. For example, the inner peripheral end of the lower surface of the rectifying member 303 is located below the surface of the wafer W on the hot plate 328. The inner circumferential side of the rectifying member 303 overlaps the peripheral edge of the hot plate 328 in a top view, but does not overlap the wafer W on the hot plate 328 in a top view. The gas rising along the gas flow path 345 passes through a gap G between the lower surface of the inner circumferential side of the rectifying member 303 and the upper surface of the peripheral edge of the hot plate 328, and flows toward the wafer W from the side of the wafer W on the hot plate 328 in the processing space K1. If the space above the surface of the hot plate 328 is defined as the processing space K1, the gap G that allows gas to flow into the processing space K1 is provided in the lower part of the processing space K1.

[0069] The gap G is connected to one end of the gas flow path 345. The other end of the gas flow path 345 is connected to a buffer space K2 below the heat plate 328 in the chamber 300. The buffer space K2 below the heat plate 328 has a larger volume than the processing space above the heat plate 328.

[0070] The inner peripheral surface of the flow regulating member 303 extends linearly downward from the ceiling portion 310 of the upper chamber 301 .

[0071] In one embodiment, the rectifying member 303 is a solid body. The rectifying member 303 is made of a metal material such as stainless steel. The entire upper surface of the rectifying member 303 is in contact with the lower surface of the upper chamber 301 . More specifically, the flow regulating member 303 is fixed to the upper chamber 301 in a manner that the entire upper surface thereof contacts the lower surface of the upper chamber 301 , and moves up and down together with the upper chamber 301 .

[0072] The rectifying member 303 descends together with the upper chamber 301 and abuts against the lower chamber 302 (specifically, the support ring 337), thereby closing the chamber 300. To prevent dust generation due to contact between the metallic rectifying member 303 and the metallic support ring 337, the following may be adopted. Specifically, a resin protrusion may be provided on the surface of the support ring 337 facing the rectifying member 303, so that the rectifying member 303 comes into contact with the resin protrusion when it descends. Alternatively, a resin protrusion may be provided on the surface of the rectifying member 303 facing the support ring 337, so that the rectifying member 303 comes into contact with the support ring 337 when it descends. In these cases, it is preferable that the height of the resin protrusion be as small as possible. This is to reduce the gap between the lower surface of the rectifying member 303 and the upper surface of the support ring 337 and prevent sublimates and the like from entering this gap. The height of the resin protrusion is at least such that the gap between the lower surface of the rectifying member 303 and the upper surface of the support ring 337 is smaller than the shortest distance from the rectifying member 303 to the wafer W on the heating plate 328 .

[0073] The heat treatment apparatus 40 may further include a cooling plate (not shown) that has the function of cooling the wafer W. The cooling plate, for example, reciprocates between a cooling position outside the chamber 300 and a transfer position where at least a portion of the cooling plate is disposed inside the chamber 300 and where the wafer W is transferred between the cooling plate and the heating plate 328. Alternatively, the cooling plate may be fixed at a position horizontally aligned with the heating plate 328, and the heat treatment apparatus 40 may include a transfer arm that transfers the wafer W between the cooling plate and the heating plate 328.

[0074] <Wafer Processing Using Heat Treatment Device 40> Next, an example of wafer processing performed using heat treatment apparatus 40 will be described with reference to Figures 6 to 8. Figures 6 to 8 are views showing the state of heat treatment apparatus 40 during wafer processing performed using heat treatment apparatus 40. The following wafer processing is performed under the control of control unit 200.

[0075] (Step S1: Adjusting the condition inside the chamber) First, for example, before the wafer W is placed on the heating plate 328, the condition inside the chamber 300 is adjusted. Specifically, the temperature of the hot plate 328 is adjusted to a predetermined temperature. 6A, the humidity in the processing space K1 is adjusted by exhausting the gas from the central exhaust unit 317, exhausting the gas from the peripheral exhaust unit 323, and discharging the processing gas from the shower head 311.

[0076] (Step S2: Wafer placement) Next, the wafer W coated with the metal-containing resist is placed on the heating plate 328. Specifically, as shown in FIG. 6(b), exhaust by the peripheral exhaust unit 323 and discharge of the process gas from the shower head 311 continue, but only exhaust by the central exhaust unit 317 is stopped, and the upper chamber 301 is raised. Thereafter, the wafer W is transported above the hot plate 328 by the transfer device 70. Next, the lift pins are raised and lowered, and the wafer W is transferred from the transfer device 70 to the lift pins and from the lift pins to the hot plate 328. As shown in FIG. 7(a), the wafer W is placed on the hot plate 328. Thereafter, the wafer W is adsorbed to the hot plate 328 via the adsorption holes 330.

[0077] (Step S3: PEB processing) Subsequently, the wafer W on the heating plate 328 is subjected to PEB processing.

[0078] (Step S3a: Start of PEB processing) 7(b), the upper chamber 301 is lowered, the flow rectifying member 303 contacts the support ring 337 of the lower chamber 302, and the chamber 300 is closed. This starts the PEB process for the wafer W on the heating plate 328.

[0079] Until a first predetermined time has elapsed since the start of the PEB process, exhaust by the central exhaust unit 317 is not performed, and gas is discharged from the shower head 311 and exhausted by the peripheral exhaust unit 323. Furthermore, the process gas is discharged from the shower head 311 and exhausted by the peripheral exhaust unit 323 so that gas is supplied by the gas supply unit 344. For example, control is performed so that the exhaust flow rate L2 from the processing space K1 by the peripheral exhaust unit 323 is greater than the discharge flow rate L1 from the shower head 311 to the processing space K1. As a result, a gas corresponding to the flow rate (L2-L1) is taken into the chamber 300 from outside the chamber 300 through the inlet 343. Then, a gas corresponding to the flow rate (L2-L1) is supplied from the gas supply unit 344 toward the wafer W on the heating plate 328. The flow rate of gas supplied from the gas supply unit 344 toward the wafer W on the heating plate 328 is approximately uniform in the circumferential direction. The intake port 343 can be said to be an introduction portion for the gas to be introduced into the processing space K1 at a position below the heating plate 328.

[0080] When exhaust is performed only by the peripheral exhaust unit 323, a flow of the processing gas is formed in the vicinity of the surface of the wafer W, moving radially along the surface of the wafer W toward the peripheral edge of the wafer W. In contrast, when exhaust is performed using the central exhaust unit 317, the process gas does not flow along the surface of the wafer W, but flows upward from the periphery of the wafer W toward the center. As a result, the distance between the boundary layer of the process gas flow toward the central exhaust unit 317 and the surface of the wafer W varies across the surface of the wafer W. This causes variations in the amount of evaporation from the coating on the wafer W. This variation in the amount of evaporation adversely affects the in-plane uniformity of the film thickness on the wafer W when solidification is not yet advanced and the amount of evaporation is large in the early stages of PEB processing.

[0081] Therefore, as described above, exhaust by the central exhaust unit 317 is not performed until the first predetermined time has elapsed from the start of the PEB process, and gas is discharged from the shower head 311 and exhaust by the peripheral exhaust unit 323. The first predetermined time is set so that the metal-containing resist coating on the wafer W is solidified to a desired level. In other words, the first predetermined time is set so that dehydration condensation of the metal-containing resist on the wafer W progresses to a desired level.

[0082] Furthermore, since the process gas is discharged from the shower head 311 and exhausted by the peripheral exhaust unit 323 so that the gas is supplied by the gas supply unit 344, the gas supplied from the gas supply unit 344 toward the wafer W moves toward the exhaust port 324, forming an upward flow around the wafer W. At this time, the process gas, which may contain sublimates and which is discharged from the shower head 311 toward the wafer W and moves along the surface of the wafer W, also moves upward together with the upward flow and is exhausted to the outside via the exhaust port 324. Therefore, it is possible to prevent the sublimates from adhering to the back surface or bevel of the wafer W.

[0083] During the PEB process, the upper chamber 301 is heated to prevent sublimates from re-solidifying and adhering to the upper chamber 301. During the PEB process, the process gas supplied from the shower head 311 is heated by the heated upper chamber 301. During the PEB process, the gas supplied from the gas supply unit 344 toward the wafer W on the heating plate 328 is gas taken into the chamber 300 from the intake port 343, and is gas heated by the heating plate 328 in the buffer space K2 or gas heated by the gas taken into the chamber 300. During the PEB process, the gas supplied from the gas supply unit 344 toward the wafer W on the heating plate 328 is also heated by the rectifying member 303 heated by the upper chamber 301.

[0084] (Step S3b: Start of central exhaust) When a first predetermined time has elapsed since the start of the PEB process, exhaust by the central exhaust unit 317 begins while gas continues to be discharged from the shower head 311 and exhaust by the peripheral exhaust unit 323 continues. As described above, the first predetermined time is set so that the metal-containing resist coating on the wafer W solidifies to a desired level. Information about the first predetermined time is stored in a storage unit (not shown).

[0085] In this stage, exhaust by the central exhaust unit 317, discharge of the process gas from the shower head 311, and exhaust by the peripheral exhaust unit 323 are performed so that gas is supplied by the gas supply unit 344. For example, control is performed so that the sum of the exhaust flow rate L2 from the processing space K1 by the peripheral exhaust unit 323 and the exhaust L3 by the central exhaust unit 317 is greater than the discharge flow rate L1 from the shower head 311 to the processing space K1. In other words, control is performed so that L2 + L3 > L1. As a result, a gas corresponding to the flow rate (L2 + L3 - L1) is taken into the chamber 300 from outside the chamber 300 through the inlet 343. Then, a gas corresponding to the flow rate (L2 + L3 - L1) is supplied from the gas supply unit 344 toward the wafer W on the heating plate 328. The flow rate of the gas supplied from the gas supply unit 344 toward the wafer W on the heating plate 328 is approximately uniform in the circumferential direction.

[0086] By operating the central exhaust unit 317, a flow of process gas is formed near the surface of the wafer W, flowing from the outer periphery of the wafer W toward the center of the wafer W. Therefore, process gas that may contain sublimates near the surface of the wafer W is also exhausted via the central exhaust unit 317. The exhaust volume of the central exhaust unit 317 may be greater than the exhaust volume of the peripheral exhaust unit 323. In this case, process gas that may contain sublimates near the surface of the wafer W is mainly exhausted via the central exhaust unit 317. This further prevents sublimates from adhering to the backside or bevel of the wafer W. At the stage of exhausting using the central exhaust unit 317, the metal-containing resist coating has already solidified, and the airflow associated with the exhaust has little effect on film thickness fluctuations. Therefore, exhausting using the central exhaust unit 317 has little effect on the in-plane film thickness uniformity.

[0087] (Step S3c: Stop PEB processing) The PEB process ends when a second predetermined time has elapsed since the start of exhaust by the central exhaust unit 317. Specifically, for example, the upper chamber 301 is raised and the chamber 300 is opened. At this time, exhaust by the central exhaust unit 317, discharge of the processing gas from the shower head 311, and exhaust by the peripheral exhaust unit 323 continue. The second predetermined time is set so that the metal-containing resist coating on the wafer W is solidified to a desired level. Information about the second predetermined time is stored in a storage unit (not shown).

[0088] The first and second predetermined times are set as follows: That is, the time during which exhaust is performed by the central exhaust unit 317 is set to a ratio of 1 / 20 to 1 / 2 of the total time of the PEB process. More specifically, when the total time of the PEB process is 60 seconds, the time during which exhaust is performed by the central exhaust unit 317 is set to 3 to 30 seconds. The total time of the PEB process is, for example, the time from when the upper chamber 301 is lowered and the chamber 300 is closed after the wafer W is placed on the heating plate 328 until the upper chamber 301 is raised and the chamber 300 is opened.

[0089] (Step S4: Unloading the wafer) Thereafter, the wafer W is removed from the heating plate 328 in the reverse order to that used when the wafer W was placed, and is carried out to the outside of the heat treatment apparatus 40.

[0090] <Modification> In the above example, when the PEB process starts, exhausting by the central exhaust unit 317 is not performed, and halfway through the PEB process, exhausting by the central exhaust unit 317 is performed. Alternatively, when the PEB process starts, exhausting by the central exhaust unit 317 may be performed weakly, and halfway through the PEB process, exhausting by the central exhaust unit 317 may be performed strongly.

[0091] Furthermore, the control unit 200 may perform control so that the supply flow rate of the processing gas to the gas distribution space 313 of the shower head 311 is increased during a period during which exhaust by the central exhaust unit 317 is performed or during which exhaust by the central exhaust unit 317 is strengthened (hereinafter referred to as a central exhaust strengthening period) from the middle of the PEB process. The reason for this is as follows. The peripheral-side outlet holes 312 and the central-side outlet holes 312 share the gas distribution space 313. Furthermore, during the central exhaust intensification period, the discharge flow rate of the processing gas from the central-side outlet holes 312 closer to the central exhaust unit 317 (specifically, the exhaust holes 318) increases. Therefore, during the central exhaust intensification period, depending on the strength of the exhaust by the central exhaust unit 317, as shown in FIG. 9 , the processing gas may not be discharged from the peripheral-side outlet holes 312 to the processing space K1, and instead, the peripheral-side outlet holes 312 may suck in gas from the processing space K1. By increasing the supply flow rate of the processing gas to the gas distribution space 313 of the showerhead 311 during the central exhaust intensification period, the above-mentioned sucking of gas from the processing space K1 by the peripheral-side outlet holes 312, i.e., backflow of gas into the showerhead 311, can be suppressed.

[0092] <Major Effects of This Embodiment> As described above, in this embodiment, the heat treatment apparatus 40 includes the heating plate 328 that supports and heats the wafer W, and the chamber 300 that houses the heating plate 328 and has a ceiling 310 that faces the wafer W on the heating plate 328. The heat treatment apparatus 40 also includes the shower head 311 that is provided on the ceiling 310 and discharges a process gas toward the wafer W from above, and the gas supply unit 344 that supplies gas toward the wafer W from below the surface of the wafer W. The heat treatment apparatus 40 also includes the central exhaust unit 317 that exhausts the processing space K1 above the heating plate 328 in the chamber 300 from a position on the ceiling 310 closer to the center of the wafer W in a top view, the peripheral exhaust unit 323 that exhausts the processing space K1 from a position on the ceiling 310 closer to the peripheral edge of the wafer W than the central exhaust unit 317 in a top view, and the control unit 200. The control unit 200 then controls the gas discharge unit to continue discharging, the gas supply unit to supply gas, and the peripheral exhaust unit to continue exhausting during the heat treatment, while increasing the exhaust strength of the central exhaust unit midway through the heat treatment.

[0093] The wafer processing according to this embodiment includes a step of placing the wafer W on the heating plate 328 and a step of heat-treating the wafer W on the heating plate 328. The heat-treating step includes: (A) a step of discharging a processing gas toward the wafer W from a ceiling portion 310 facing the wafer W of a chamber 300 accommodating a heating plate 328; (B) supplying a gas toward the wafer W from below the surface of the wafer W; (C) exhausting the processing space K1 above the heating plate 328 in the chamber 300 from a position on the ceiling 310 near the center of the wafer W in top view; (D) A step of evacuating the processing space K1 from the ceiling portion 310 closer to the peripheral edge of the wafer W than in the step (C) in a top view. In this wafer processing, the above-mentioned (A) step is continuously performed during the heat treatment, and the above-mentioned (B) step and the above-mentioned (D) step are continuously performed to form an upward flow around the wafer W, and the exhaust in the above-mentioned (C) step is strengthened from the middle of the heat treatment.

[0094] That is, in this embodiment, the supply of the process gas to the wafer W on the heating plate 328 and the exhaust of the gas from the ceiling 310 from a position closer to the periphery of the wafer W on the heating plate 328 are continued during the heat treatment. This improves the in-plane uniformity of the heat treatment. This also reduces contamination of the bevel and backside of the wafer W due to sublimates generated from the resist coating on the wafer W. Furthermore, exhaust from the ceiling 310 from a position closer to the peripheral edge of the wafer W on the heating plate 328 and supply of gas toward the wafer W from below the surface of the wafer W on the heating plate 328 are continued during the heat treatment. As a result, an upward flow is formed at the peripheral edge of the wafer W. Furthermore, in this embodiment, as the heat treatment progresses, the influence of exhaust from a position closer to the center of the wafer W on the heating plate 328 (i.e., central exhaust) on film thickness fluctuations becomes smaller, and then central exhaust, which is excellent in recovering sublimates, is performed. Therefore, contamination of the wafer W by sublimates generated from the resist coating on the wafer W can be further suppressed.

[0095] Therefore, according to this embodiment, contamination of the wafer W due to sublimates generated from the resist coating on the wafer can be suppressed, and the uniformity of the heat treatment within the wafer surface can be improved. Furthermore, since an upward flow is formed as described above, according to this embodiment, it is possible to prevent the sublimate from adhering to members (for example, the chamber 300) located around the hot plate 328.

[0096] In this embodiment, the gas supplied by the gas supply unit 344 from below the surface of the wafer on the heating plate 328 toward the wafer W on the heating plate 328 is gas heated by the heating plate 328 in the buffer space K2 or gas heated by the heated gas. The buffer space K2 has a larger volume than the processing space K1. Therefore, the heated gas can be supplied to the processing space K1 for as long as possible. If unheated gas is supplied to the processing space K1, the gas may cool components surrounding the processing space K1 (e.g., the upper chamber 301), causing the sublimates to solidify. In this embodiment, the heated gas can be supplied to the processing space K1 for as long as possible, thereby preventing the solidification of the sublimates. Furthermore, if unheated gas is supplied from the gas supply unit 344 toward the wafer W, it may affect the heat treatment of the peripheral portion of the wafer W. In contrast, in this embodiment, the gas supplied from the gas supply unit 344 toward the wafer W is heated, thereby preventing the gas from deteriorating the in-plane uniformity of the heat treatment. On the other hand, since the volume of the processing space K1 is small, the heat capacity of the gas inside the processing space K1 is also small, so the temperature of the processing space K1 is more likely to be stable when the heated gas is supplied to the processing space K1 for a long period of time.

[0097] Furthermore, in this embodiment, the upper chamber 301 is configured to be heatable. The entire upper surface of the rectifying member 303 is in contact with the lower surface of the upper chamber 301. Therefore, the rectifying member 303 can be efficiently heated by heating the upper chamber 301. Furthermore, the rectifying member 303 is a solid body with a large heat capacity. Therefore, by heating the rectifying member 303, the gas supplied from the gas supply unit 344 can be efficiently heated by the rectifying member 303. Therefore, according to this embodiment, the gas supplied from the gas supply unit 344 can be heated by the heated upper chamber 301. Therefore, the solidification of the sublimate and the deterioration of the in-plane uniformity of the heat treatment, which are caused by the gas supplied from the gas supply unit 344, can be suppressed.

[0098] Furthermore, in this embodiment, the rectifying member 303 moves up and down together with the upper chamber 301. Therefore, the rectifying member 303 is heated by the upper chamber 301 regardless of the position of the upper chamber 301. In other words, even when the upper chamber 301 is raised and the chamber 300 is in the open state in order to place the wafer W on the hot plate 328, the rectifying member 303 is heated by the upper chamber 301. As a result, the rectifying member 303 can be maintained at a high temperature. Therefore, according to this embodiment, even immediately after the chamber 300 is closed, the gas supplied from the gas supply unit 344 can be heated by the rectifying member 303. This makes it possible to suppress the solidification of the sublimate and the deterioration of the in-plane uniformity of the heat treatment, which are caused by the gas supplied from the gas supply unit 344.

[0099] Furthermore, in this embodiment, the inner peripheral surface of the rectifying member 303 extends linearly downward from the ceiling portion 310 of the upper chamber 301. In other words, the inner peripheral side of the rectifying member 303 does not have a recess that is recessed outward above the lower surface, i.e., the guide surface, of the inner peripheral side. If such a recess were to exist, gas that may contain sublimates would remain in the recess, causing particles. In contrast, the absence of such a recess makes it possible to suppress the generation of particles.

[0100] The shape of the inner circumferential surface of rectifying member 303 extending downward from ceiling portion 310 of upper chamber 301 does not have to be a perfect straight line; in other words, the inner circumferential surface of rectifying member 303 may be slightly recessed outward as long as gas does not stagnate. For example, in order to prevent damage to the upper corners of the inner circumferential surface of rectifying member 303, the upper corners may be chamfered, and as a result, the inner circumferential surface of rectifying member 303 may be recessed outward. The recess formed by chamfering to prevent damage to the corners is sufficiently small so that gas does not stagnate, and even if it does stagnate, the impact is small.

[0101] Furthermore, in this embodiment, the resin pad 335 communicates with the suction holes 330 and is connected to the hot plate 328 via the metal member 334. Therefore, according to this embodiment, deterioration of the resin pad 335 due to heat from the hot plate 328 can be suppressed compared to when the resin pad 335 is directly connected to the hot plate 328.

[0102] <Confirmation test> Tests were conducted to measure the line width of the resist pattern of a metal-containing resist and the number of metal atoms on the backside and bevel of the wafer W in the following cases 1-3. Figures 10 to 14 show the test results. Figures 10 to 12 each show the thickness of the line width of the resist pattern in shades of black. The vertical axis of Figure 13 shows 3σ of the line width of the resist pattern on a linear scale, which represents the critical dimension uniformity (CDU) of the line width of the resist pattern. The vertical axis of Figure 14 shows the number of metal atoms per unit area on a logarithmic scale.

[0103] (Case 1) A conventional heat treatment apparatus was used that did not have the gas supply unit 344. During the PEB treatment, exhaust was performed by the central exhaust unit 317 and the processing gas was discharged from the shower head 311, but exhaust by the peripheral exhaust unit 323 was not performed. (Case 2) The heat treatment apparatus 40 shown in Fig. 4 was used. Exhaust by the peripheral exhaust unit 323 and discharge of the processing gas from the shower head 311 were performed so that gas was continuously supplied from the gas supply unit 344 from the start to the end of the PEB treatment. Furthermore, exhaust by the central exhaust unit 317 was not performed at all during the PEB treatment. (Case 3) 4 and other figures was used. Exhaust was performed by the peripheral exhaust unit 323 and processing gas was discharged from the shower head 311 so that gas was continuously supplied from the gas supply unit 344 from the start to the end of the PEB process. In addition, exhaust was performed by the central exhaust unit 317 from the middle of the PEB process to the end of the PEB process.

[0104] In all of cases 1 to 3, after the PEB process, a development process and a POST process were performed to form a resist pattern of metal-containing resist, and then the line width of the resist pattern and the number of metal atoms on the back surface and bevel of the wafer W were measured.

[0105] In Case 1, as shown in Figure 10, there was a large difference in the line width of the resist pattern between the center and the periphery of the wafer W. In contrast, in Cases 2 and 3, as shown in Figures 11 and 12, there was almost no difference in the line width of the resist pattern between the center and the periphery of the wafer W. Furthermore, as shown in FIG. 13, in Cases 2 and 3, 3σ (σ is the line width of the resist pattern), which indicates the in-plane uniformity (CDU) of the line width of the resist pattern, was approximately half that of Case 1.

[0106] Furthermore, as shown in FIG. 14, in Case 2, the number of metal atoms on the back surface and bevel of the wafer W was about 1 / 10 of that in Case 1. In contrast, in Case 3, the number of metal atoms on the back surface and bevel of the wafer W was about 1 / 100 of that in Case 1. These results also show that this embodiment can suppress contamination of the wafer W by sublimates generated from the resist coating on the wafer W, and can improve the uniformity of the heat treatment across the wafer surface.

[0107] The embodiments disclosed herein should be considered to be illustrative in all respects and not restrictive, and the above-described embodiments may be omitted, substituted, or modified in various ways without departing from the scope and spirit of the appended claims. [Explanation of symbols]

[0108] 40 Heat treatment equipment 200 control section 300 Chamber 310 Ceiling 311 shower head 317 Central exhaust section 323 Peripheral exhaust 328 Hot plate 344 Gas Supply Section K1 Processing Space W wafer

Claims

1. A heat treatment apparatus for heat treating a substrate on which a resist film is formed, a hot plate that supports and heats the substrate; a chamber that accommodates the hot plate; the chamber has a ceiling portion that forms a processing space below which the heat treatment is performed and faces the substrate on the heat plate; a gas discharge unit provided in the ceiling portion and configured to discharge a processing gas from above toward the substrate on the hot plate; a gas supply unit configured to supply gas from a side of the substrate on the hot plate and from a lower part of the processing space toward the substrate on the hot plate; a central exhaust section that exhausts air from the processing space in the chamber from a position in the ceiling section that is close to the center of the substrate on the hot plate in a top view; a peripheral exhaust section in the ceiling section that exhausts air from inside the processing space from a side closer to a peripheral portion of the substrate on the hot plate than the central exhaust section and the gas discharge section in a top view; a control unit, the control unit performs control so that, during the heat treatment, the discharge by the gas discharge unit, the supply of gas by the gas supply unit, and the exhaust by the central exhaust unit and the peripheral exhaust unit are performed, and the exhaust by the central exhaust unit is strengthened from the middle of the heat treatment; The gas supply unit is a gas flow path provided so as to surround a side surface of the hot plate; a straightening member that directs the gas that has risen along the gas flow path toward the substrate on the hot plate, the gas flow path is connected to a buffer space below the hot plate in the chamber; The thermal processing apparatus, wherein the buffer space has a volume larger than that of the processing space.

2. The heat treatment apparatus according to claim 1 , wherein the heat treatment apparatus processes the substrate on which a metal-containing resist film is formed as the film.

3. the chamber has an upper chamber including the ceiling portion and configured to be freely raised and lowered; The upper chamber is configured to be heatable, The flow rectifying member is It is a solid body, The heat treatment apparatus according to claim 1 or 2, wherein the entire upper surface thereof is in contact with the lower surface of the upper chamber.

4. the chamber has an upper chamber including the ceiling portion and configured to be freely raised and lowered; The upper chamber is configured to be heatable, The flow rectifying member is It is a solid body, 3. The heat treatment apparatus according to claim 1, wherein the entire upper surface of the heat treatment apparatus is fixed to the upper chamber in contact with the lower surface of the upper chamber, and the heat treatment apparatus moves up and down together with the upper chamber.

5. the hot plate has suction holes for suction-holding the substrate to the hot plate; a resin pad having a flow path communicating with the suction hole; 5. The heat treatment apparatus according to claim 1, wherein the resin pad communicates with the suction holes and is connected to the heat plate via a metal member.

6. The heat treatment apparatus according to claim 5 , wherein the metal member has a large diameter portion.

7. Further, an annular member is provided which is connected to the lower side of the hot plate via a support pillar, The heat treatment apparatus according to claim 5 , wherein the resin pad is located below the annular member.

8. A heat treatment apparatus described in any one of claims 1 to 7, wherein the control unit controls the flow rate of the processing gas supplied toward the gas discharge section to be increased during a period when the exhaust from the central exhaust section is stronger.

9. A heat treatment method for heat treating a substrate on which a resist film is formed, comprising the steps of: placing the substrate on a hot plate that supports and heats the substrate; and heat-treating the substrate on the hot plate, The heat treatment step includes: (A) discharging a processing gas toward the substrate on the hot plate from a ceiling portion of a chamber accommodating the hot plate, the ceiling portion facing the substrate on the hot plate and defining a processing space below where the heat processing is performed; (B) supplying a gas from a side of the substrate on the heat plate and a lower part of the processing space where the heat processing is performed toward the substrate on the heat plate; (C) exhausting the processing space in the chamber from a position on the ceiling near the center of the substrate on the hot plate in a top view; (D) exhausting the processing space from the ceiling portion, from a side of the peripheral edge of the substrate on the hot plate relative to the exhaust position in the (C) step and the discharge position in the (A) step, in a top view; During the heat treatment, the steps (A), (B), and (D) are continuously performed to form an upward flow around the substrate on the hot plate, and the exhaust in the step (C) is strengthened from the middle of the heat treatment, The step (B) includes directing the gas rising along the gas flow path provided so as to surround the side surface of the hot plate toward the substrate on the hot plate by a straightening member; the gas flow path is connected to a buffer space below the hot plate in the chamber; The thermal processing method, wherein the buffer space has a volume larger than that of the processing space.

10. A readable computer storage medium storing a program that runs on a computer of a control unit that controls a heat treatment apparatus to cause the heat treatment apparatus to perform the heat treatment method according to claim 9.

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