TWI902892B - Heat treatment device, heat treatment method, and storage device - Google Patents

Abstract

A heat treatment device which conducts a heat treatment of a substrate on which a resist coating film has been formed and subjected to exposure processing, the heat treatment device comprising a heating plate which supports and heats the substrate, and a chamber which accommodates the heating plate, and the chamber has a ceiling section which faces the substrate on the heating plate and forms a processing space thereunder in which the heat treatment is performed, a gas discharge section which is provided in the ceiling section and discharges a process gas toward the substrate on the heating plate from above, an air supply section which supplies air toward the substrate on the heating plate from the side of the substrate within the bottom of the processing space, a central exhaust section which exhausts the contents of the processing space in the chamber from a position in the ceiling section near the center of the substrate on the heating plate when viewed from above, a peripheral exhaust section which exhausts the contents of the processing space from a position in the ceiling section further toward the periphery of the substrate on the heating plate than the central exhaust section when viewed from above, and a control section, wherein the control section performs control such that, during the heat treatment, discharge by the gas discharge section, supply of air by the air supply section, and exhaust by the peripheral exhaust section occur continuously, and exhaust by the central exhaust section increases in intensity from partway through the heat treatment process.

Description

Heat treatment apparatus, heat treatment method and recording media

This invention relates to a heat treatment apparatus, a heat treatment method, and a recording medium.

Patent 1 discloses a method for patterning a substrate using radiation. The method includes irradiating a substrate along a selected pattern to form an irradiation structure having regions of an irradiated coating and regions of the irradiated coating. The substrate includes a coating layer comprising a metal oxide-hydroxo network with organic ligands through metal carbon bonds and/or metal carboxylate bonds. [Prior Art Documents] [Patent Documents]

[Patent Document 1] Japanese Patent Publication No. 2016-530565

[The problem the invention aims to solve]

The present invention suppresses substrate contamination caused by sublimation generated from photoresist coatings on the substrate, and improves the in-plane uniformity of the substrate after heat treatment. [Means for solving the problem]

One aspect of this invention is a heat treatment apparatus for heat-treating a substrate on which a photoresist coating has been formed and which has undergone exposure treatment. The heat treatment apparatus comprises: a hot plate for supporting and heating the substrate; and a chamber for housing the hot plate. The chamber has a top portion with a processing space formed below it, facing the substrate on the hot plate. The chamber further comprises: a gas discharge section disposed at the top portion for discharging processing gas upwards toward the substrate on the hot plate; and a gas supply section for supplying gas from the side of the substrate on the hot plate, i.e., below the processing space, toward the substrate on the hot plate. The invention comprises: a plate supplying gas; a central exhaust section, located at the center of the substrate on the hot plate when viewed from the top, exhausting gas from the processing space within the chamber; a peripheral exhaust section, located at the periphery of the substrate on the hot plate when viewed from the top, further exhausting gas from the processing space; and a control unit, which, in addition to continuously discharging gas from the gas discharge section, supplying gas from the gas supply section, and exhausting gas from the peripheral exhaust section during the heat treatment, also controls the exhaust from the central exhaust section to be stronger during the heat treatment process. [Effects of the Invention]

According to the present invention, it is possible to suppress substrate contamination caused by sublimation generated by photoresist coating on the substrate and improve the in-plane uniformity of the heat-treated substrate.

In the manufacturing process of semiconductor devices, predetermined processes are performed to form photoresist patterns on semiconductor wafers (hereinafter referred to as "wafers"). These predetermined processes include, for example, photoresist coating processes, which involve supplying photoresist liquid to the wafer to form a photoresist coating; exposure processes, which expose the coating to light; PEB (Post Exposure Bake) processes, which involve heating after exposure to promote chemical reactions within the coating; and development processes, which involve developing the exposed coating.

PEB processing, for example, involves venting ambient gases from the substrate. In this case, depending on the venting method, the dimensions of the photoresist pattern may vary within the plane. Furthermore, if the photoresist is produced using sublimates containing metals, the beveled surfaces and back surface of the substrate may become contaminated with the sublimate, depending on the venting method.

In view of this, the technology of the present invention can suppress substrate contamination caused by sublimation generated by photoresist coating on the substrate, and improve the in-plane uniformity of the heat-treated substrate.

The heat treatment apparatus and heat treatment method related to this embodiment will be described below with reference to the drawings. Furthermore, in this specification and drawings, elements with substantially the same functional configuration are given the same symbols and repeated descriptions are omitted.

<Coating and Development System> Figure 1 is a schematic explanatory diagram showing the internal structure of a coating and development system that includes a heat treatment apparatus related to this embodiment and serves as a substrate processing system. Figures 2 and 3 are schematic diagrams showing the internal structure of the front and back sides of the coating and development system, respectively.

The coating and display system 1 uses photoresist to form a photoresist pattern on a wafer W, which serves as a substrate. The photoresist used is a photoresist that produces sublimates, such as a photoresist containing metal. Furthermore, the metal contained in the photoresist containing metal can be arbitrary, such as tin.

The coating and developing system 1, as shown in Figures 1 to 3, includes: a cassette workstation 2, which holds multiple wafers (cassettes C) for loading and unloading; and a processing workstation 3, equipped with various processing devices for performing predetermined processes such as photoresist coating. The coating and developing system 1 is configured to integrally connect the following parts: the cassette workstation 2; the processing workstation 3; and an interface workstation 5, which transfers wafers W between the interface workstation 5 and the exposure device 4 adjacent to the processing workstation 3.

The cartridge workstation 2 is, for example, divided into a cartridge loading/unloading section 10 and a wafer transport section 11. For example, the cartridge loading/unloading section 10 is located at the end of the coating and development system 1 on the negative Y-direction (left direction in FIG. 1). A cartridge loading/unloading stage 12 is provided in the cartridge loading/unloading section 10. Multiple (e.g., four) mounting plates 13 are provided on the cartridge mounting stage 12. The mounting plates 13 are arranged in a row in the horizontal X-direction (vertical direction in FIG. 1). These mounting plates 13 can hold cartridges C when loading/unloading cartridges C from the outside of the coating and development system 1.

In the wafer transport section 11, a transport device 20 for transporting wafers W is provided. The transport device 20 is configured to move freely along a transport path 21 that extends in the X direction. The transport device 20 can move freely in the vertical direction and around the vertical axis (θ direction), and can transport wafers W between the cassettes C on each mounting plate 13 and the transfer device of the third block G3 of the processing workstation 3 described later.

In processing workstation 3, multiple blocks equipped with various devices are provided, such as the four blocks G1, G2, G3, and G4, numbered 1 to 4. For example, block G1 is provided on the front side of processing workstation 3 (the negative X-direction side in Figure 1), and block G2 is provided on the back side of processing workstation 3 (the positive X-direction side in Figure 1). Furthermore, block G3 is provided on the cassette workstation 2 side of processing workstation 3 (the negative Y-direction side in Figure 1), and block G4 is provided on the interface workstation 5 side of processing workstation 3 (the positive Y-direction side in Figure 1).

In section G1, as shown in Figure 2, multiple liquid processing devices are arranged sequentially from bottom to top, such as a developing device 30, a lower anti-reflection film forming device 31, a photoresist coating device 32, and an upper anti-reflection film forming device 33. The developing device 30 performs developing processing on the wafer W. Specifically, the developing device 30 performs developing processing on the metal-containing photoresist film of the wafer W undergoing PEB processing. The lower anti-reflection film forming device 31 forms an anti-reflection film (hereinafter referred to as "lower anti-reflection film") on the lower layer of the metal-containing photoresist film on the wafer W. The photoresist coating device 32 coats the wafer W with metal-containing photoresist to form a metal-containing photoresist coating, i.e., a metal-containing photoresist film. The upper anti-reflection film forming device 33 forms an anti-reflection film (hereinafter referred to as "upper anti-reflection film") on the metal-containing photoresist film of the wafer W.

For example, the developing apparatus 30, the lower anti-reflection film forming apparatus 31, the photoresist coating apparatus 32, and the upper anti-reflection film forming apparatus 33 are each arranged in three units in the horizontal direction. Furthermore, the number and arrangement of these developing apparatus 30, lower anti-reflection film forming apparatus 31, photoresist coating apparatus 32, and upper anti-reflection film forming apparatus 33 can be arbitrarily selected.

In the developing apparatus 30, the lower anti-reflection film forming apparatus 31, the photoresist coating apparatus 32, and the upper anti-reflection film forming apparatus 33, a predetermined processing liquid is coated on the wafer W, for example, by a spin coating method. By the spin coating method, for example, the processing liquid is ejected from a nozzle onto the wafer W, and the wafer W is rotated, causing the processing liquid to diffuse on the surface of the wafer W.

For example, in section 2 G2, as shown in Figure 3, the heat treatment apparatus 40 for heat treatment of wafer W is arranged in both vertical and horizontal directions. The number or configuration of the heat treatment apparatus 40 can be arbitrarily selected. Furthermore, the heat treatment apparatus 40 performs pre-baking treatment (hereinafter referred to as "PAB processing") on the wafer W after photoresist coating, PEB processing on the wafer W after exposure processing, and post-baking treatment (hereinafter referred to as "POST processing") on the wafer W after development processing.

For example, in section 3 G3, multiple transmission devices 50, 51, 52, 53, 54, 55, and 56 are arranged sequentially from below. Also, in section 4 G4, multiple transmission devices 60, 61, and 62, as well as a back-side cleaning device 63 for cleaning the back side of wafer W, are arranged sequentially from below.

As shown in Figure 1, a wafer transport area D is formed in the area surrounded by the first block G1 to the fourth block G4. In the wafer transport area D, for example, a transport device 70 is arranged as a substrate transport device for transporting wafers W.

The transport device 70, for example, has a transport arm 70a that can move freely along the Y direction, the θ direction, and the vertical direction. The transport device 70 moves the transport arm 70a holding the wafer W within the wafer transport area D, and can transport the wafer W to predetermined devices in the surrounding first block G1, second block G2, third block G3, and fourth block G4. For example, as shown in FIG. 3, multiple transport devices 70 are arranged vertically, for example, capable of transporting the wafer W to predetermined devices at the same height in each block G1 to G4.

Furthermore, in the wafer transport area D, a connecting transport device 80 is installed between the third block G3 and the fourth block G4 to transport wafers W linearly.

The connecting transport device 80 moves the supported wafer W in a straight line along the Y direction, and the wafer W can be transported between the transfer device 52 of the third block G3 and the transfer device 62 of the fourth block G4 at the same height.

As shown in Figure 1, a transport device 90 is provided on the positive X-direction side of the third block G3. The transport device 90 has, for example, a transport arm 90a that can move freely along the θ-direction and the vertical direction. The transport device 90 moves the transport arm 90a holding the wafer W vertically, thereby transporting the wafer W to various transfer devices within the third block G3.

In the interface workstation 5, a transport device 100 and a transfer device 101 are provided. The transport device 100 has, for example, a transport arm 100a that can move freely along the θ direction and the up-down direction. The transport device 100 holds the wafer W in the transport arm 100a and can transport the wafer W between the various transfer devices, transfer devices 101 and exposure devices 4 in the fourth block G4.

As shown in FIG1, a control unit 200 is provided in the above-described coating and display system 1. The control unit 200 is, for example, a computer equipped with a processor such as a CPU or memory, and has a program storage unit (not shown). In the program storage unit, the operation of the drive systems such as the various processing devices and various transport devices described above is controlled, and the program for controlling the wafer processing described later is stored. Alternatively, the program is recorded on a non-temporary recording medium H that can be read by a computer, and can be installed from the recording medium H onto the control unit 200. The recording medium H can be temporary or non-temporary. Part or all of the program can be implemented by dedicated hardware (circuit board).

<Wafer Processing Using Coating and Display System 1> Next, an example of wafer processing using coating and display system 1 will be explained. Furthermore, the following processing is performed under the control of control unit 200.

First, the cassette C containing multiple wafers W is moved into the cassette workstation 2 of the coating and imaging system 1 and placed onto the mounting plate 13. Then, the transport device 20 sequentially removes each wafer W from the cassette C and transports it to the transfer device 53 of the third block G3 of the processing workstation 3.

Next, wafer W is transported by transport device 70 to the heat treatment device 40 in block 2 G2 for temperature regulation. Afterwards, wafer W is transported by transport device 70, for example, to the lower anti-reflection film forming device 31 in block 1 G1, where a lower anti-reflection film is formed on wafer W. Then, wafer W is transported to the heat treatment device 40 in block 2 G2 for heating. Finally, wafer W returns to the transfer device 53 in block 3 G3.

Next, wafer W is transported by transport device 70 to photoresist coating device 32, where a metal-containing photoresist film is formed on wafer W. Afterwards, wafer W is transported by transport device 70 to heat treatment device 40 for PAB processing. Finally, wafer W is transported by transport device 70 to transfer device 55 for block G3.

Next, wafer W is transported by transport device 70 to upper anti-reflection film forming device 33, where an upper anti-reflection film is formed on wafer W. Afterward, wafer W is transported by transport device 70 to heat treatment device 40, where it is heated and subjected to temperature regulation.

Then, wafer W is transported to the transfer device 56 of block G3 via the transfer device 70.

Next, wafer W is transported to transfer device 52 via transfer device 90, and then to transfer device 62 of block G4 via connecting transfer device 80. After that, wafer W is transported to back-side cleaning device 63 via transfer device 100 to clean the back side. Then, wafer W is transported to exposure device 4 via transfer device 100 of interface workstation 5, where it is exposed using EUV light to form a predetermined pattern.

Next, wafer W is transported by transport device 100 to transfer device 60 in block 4 G4. After that, wafer W is transported to heat treatment device 40 to undergo PEB processing.

Next, wafer W is transported to display processing unit 30 by transport device 70 for display. After display, wafer W is transported to heat treatment unit 40 by transport device 90 for POST processing.

Subsequently, wafer W is transported by transport device 70 to transfer device 50 of block G3, and then by transport device 20 of cassette workstation 2 to cassette C of the predetermined mounting board 13. In this way, a series of photolithography processes are completed.

<Heat Treatment Apparatus> Next, the heat treatment apparatus 40 used for PEB processing will be described. Figure 4 is a schematic longitudinal sectional view showing the configuration of the heat treatment apparatus used for PEB processing. Figure 5 is a schematic bottom view showing the configuration of the upper chamber, which will be described later.

The heat treatment apparatus 40 in Figure 4 includes a chamber 300. The chamber 300 includes an upper chamber 301, a lower chamber 302, and a rectifier 303. The upper chamber 301 is located on the upper side, and the lower chamber 302 is located on the lower side. The rectifier 303 is located between the upper chamber 301 and the lower chamber 302, specifically, between the periphery of the upper chamber 301 and the periphery of the lower chamber 302.

The upper chamber 301 is configured to be freely height-adjustable. A lifting mechanism (not shown) that powers the upper chamber 301 and is equipped with a motor or similar drive source is controlled by the control unit 200. The upper chamber 301 is, for example, formed in a circular plate shape. The upper chamber 301 has a top portion 310. A heat treatment space K1 is formed below the top portion 310 and is positioned opposite the wafer W on the hot plate 328. Furthermore, a nozzle 311 serving as a gas exhaust portion is provided on the top portion 310.

The nozzle 311 ejects processing gas from above toward the wafer W on the hot plate 328. The processing gas is, for example, a gas containing moisture. The nozzle 311 has: multiple ejection holes 312; and a gas distribution space 313.

Exhaust holes 312 are formed on the bottom surface of the nozzle 311. As shown in FIG. 5, the exhaust holes 312 are arranged substantially uniformly on the bottom surface of the nozzle 311, excluding the exhaust holes described later. The plurality of exhaust holes 312 include: a first exhaust hole located above the periphery of the wafer W on the hot plate 328; and a second exhaust hole located above the center of the wafer W on the hot plate 328.

The gas distribution space 313 distributes the processing gas supplied to it to each discharge port 312. As shown in FIG4, for the nozzle 311, a processing gas source 315 for storing the processing gas is connected via a gas supply pipe 314. A group of supply mechanisms 316 including valves for controlling the flow of the processing gas and flow regulating valves is provided in the gas supply pipe 314.

Furthermore, a central exhaust section 317 is provided at the top 310 of the upper chamber 301. The central exhaust section 317 is located near the center of the wafer W on the hot plate 328 of the top 310 when viewed from above (in the example, from the center mentioned above), allowing air to escape from the processing space K1 above the hot plate 328 within the chamber 300. The central exhaust section 317 has an exhaust port 318. As shown in FIG. 5, the exhaust port 318 is located near the center of the wafer W on the hot plate 328 on the bottom surface of the nozzle 311 when viewed from above (in the example, from the center mentioned above), and opens downwards. The central exhaust section 317 allows air to escape from the processing space K1 through the exhaust port 318. Also, although not shown, multiple exhaust ports 318 can be provided in a manner that surrounds a position directly above the center of the wafer W. At this time, in a manner that does not impair the function of venting by the central venting section 317 described later, for example, multiple vents 318 are provided in a region within one-third of the wafer radius from the center of the wafer W when viewed from above.

As shown in Figure 4, the central exhaust section 317 has a central exhaust passage 319, which extends upward from the exhaust port 318. An exhaust device 321, such as a vacuum pump, is connected to the central exhaust passage 319 via an exhaust pipe 320. An exhaust mechanism group 322, including valves for adjusting the exhaust volume, is installed in the exhaust pipe 320.

Furthermore, a peripheral vent 323 is provided at the top 310 of the upper chamber 301. Viewed from the top 310, the peripheral vent 323, compared to the central vent 317 which vents from the periphery of the wafer W on the hot plate 328, further vents air from the processing space K1. The peripheral vent 323 has an exhaust port 324. As shown in FIG. 5, the exhaust port 324 opens downwards from the bottom surface of the top 310, surrounding the outer periphery of the nozzle 311. Multiple exhaust holes are arranged along the outer periphery of the nozzle 311 via the exhaust port 324. The peripheral vent 323 vents air from the processing space K1 through this exhaust port 324.

The exhaust port 324 is, for example, located between the periphery of the exhaust port 324 and the periphery of the wafer W on the hot plate 328 when viewed from above, and 10 mm inside the wafer W.

The peripheral exhaust section 323 in Figure 4 has a peripheral exhaust path extending from the exhaust port 324. The peripheral exhaust path is connected to an exhaust device 326, such as a vacuum pump, via an exhaust pipe 325. An exhaust mechanism group 327, such as a valve for adjusting the exhaust volume, is provided in the exhaust pipe 325.

Furthermore, the upper chamber 301 is configured to be heatable. For example, a heater (not shown) for heating the upper chamber 301 is built into the upper chamber 301. The heater is controlled by the control unit 200, and the upper chamber 301 (specifically, for example, nozzle 311) is adjusted to a predetermined temperature.

The lower chamber 302 is configured to surround the hot plate 328 that supports the heating of the wafer W.

The hot plate 328 has a disc shape with thickness. Also, a heater 329 is built into the hot plate 328, for example. Then, the temperature of the hot plate 328 is controlled, for example, by the control unit 200, to heat the wafer W placed on the hot plate 328 to a predetermined temperature.

Furthermore, the hot plate 328, for example, has a plurality of adsorption holes 330 for adsorbing wafers W onto the hot plate 328. Each adsorption hole 330 is formed to penetrate the hot plate 328 in the thickness direction. Additionally, each adsorption hole 330 is connected to a relay hole 332 of the relay member 331. Each relay hole 332 is connected to a venting conduit 333 for venting gas during adsorption.

The connection between the adsorption hole 330 and the intermediate relay hole 332 is made through a metal component 334 and a resin pad 335. Specifically, the connection between the adsorption hole 330 and the intermediate relay hole 332 is made through the flow channels in the metal component 334 and the flow channels in the resin pad 335.

Metal component 334 is located on the side of adsorption hole 330, and resin pad 335 is located on the side of relay hole 332. One end of metal component 334 is directly connected to hot plate 328 (specifically, adsorption 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 connected to the corresponding adsorption hole 330 and to hot plate 328 via metal component 334. Furthermore, the other end of resin pad 335 is directly connected to relay component 331 (specifically, relay hole 332).

Metal component 334 has a large diameter portion 336 on the side of the resin pad 335. The interior of the large diameter portion 336 has a flow channel space 336a that is larger in cross-sectional area than the portion of the hot plate 328 connected to the aforementioned metal component 334, thereby reducing the risk of blockage caused by sublimation generated during heat treatment. Furthermore, due to the larger cross-sectional area of the flow channel space 336a, the heat of the gas drawn from the processing space K1 during the adsorption of the wafer W is reduced, and the gas flows toward the exhaust pipe 333 used for adsorption. In other words, the risk of degradation caused by high temperature in the machine that forms the exhaust flow channel up to the resin pad 335 and the exhaust pipe 333 can be suppressed.

Furthermore, within the lower chamber 302, below the hot plate 328, for example, three lifting pins (not shown) are provided to support and raise/lower the wafer W from below. The lifting pins are raised and lowered by a lifting mechanism (not shown) driven by a motor or similar source. This lifting mechanism is controlled by the control unit 200. Also, a through-hole (not shown) is formed in the center of the hot plate 328 through which the lifting pins pass. The lifting pins can protrude from the top surface of the hot plate through the through-hole.

Furthermore, the lower chamber 302 has a support ring 337 and a bottom chamber 338.

The support ring 337 has a cylindrical shape. The material of the support ring 337 is, for example, a metal such as stainless steel. The support ring 337 covers the outer surface of the heating plate 328. The support ring 337 is fixed to the bottom chamber 338.

The bottom chamber 338 has a bottomed cylindrical shape. The aforementioned hot plate 328 is supported, for example, by the bottom wall of the bottom chamber 338. Specifically, the hot plate 328 is supported by the bottom wall of the bottom chamber 338 via a support portion 339. The support portion 339 includes, for example: a support post 340 whose upper end is connected to the hot plate 328; an annular member 341 supporting the support post 340; and foot members 342 supporting the annular member 341 on the bottom wall of the bottom chamber 338. The annular member 341 is formed of metal and is provided with a gap, mostly separated from the back side of the hot plate 328 by the height of the support post 340. By positioning the resin pad 335 below the annular member 341 arranged as described above, the annular member 341 effectively blocks heat from the hot plate 328, making the resin pad 335 less susceptible to high temperatures (less prone to thermal degradation).

Furthermore, the lower chamber 302 has an intake port 343. The intake port 343 draws gas into the chamber 300 from the outside. The intake port 343 is formed, for example, on the cylindrical sidewall of the bottom chamber 338. And, for example, the inner circumferential surface of the sidewall of the bottom chamber 338 and the inner circumferential surface of the support ring 337 have the same diameter.

Furthermore, the chamber 300 has a gas supply section 344. The gas supply section 344 supplies gas to the wafer W on the hot plate 328 from a position below the surface (i.e., the top surface) of the wafer W on the hot plate 328.

The gas supply unit 344 includes: a gas flow channel 345, which is arranged to surround the side of the heat plate 328; and a rectifier component 303.

The gas flow channel 345 is formed, for example, by the space between the outer surface of the hot plate 328 and the inner circumferential surface of the support ring 337. Therefore, the gas flow channel 345 is formed, for example, in a ring shape when viewed from above. Furthermore, the outer surface of the hot plate 328 can be supported by the inner circumferential surface of the side wall of the lower chamber 302 via a support member, and the support member is provided with a plurality of through holes in a ring shape that penetrate in the vertical direction, and the plurality of through holes are configured as the gas flow channel 345.

The rectifier 303 is a component that directs the gas rising along the gas flow channel 345 toward the wafer W on the hot plate 328.

The rectifier 303 is, for example, formed in a ring shape when viewed from above. The inner peripheral bottom surface of the rectifier 303 serves as a guide surface for directing the gas rising along the gas flow channel 345 toward the center of the hot plate 328. The inner peripheral end of the bottom surface of the rectifier 303 is located at a height less than half the height from the processing space K1 (i.e., the surface of the hot plate 328 on which the wafer W is placed) to the bottom surface of the nozzle 311, which has the discharge hole 312 and faces the wafer W on the hot plate 328. For example, the inner peripheral end of the bottom surface of the rectifier 303 is located closer to below the surface of the wafer W on the hot plate 328. The inner peripheral side of the rectifier 303 overlaps with the periphery of the hot plate 328 when viewed from above, but does not overlap with the wafer W on the hot plate 328 when viewed from above. Gas rising along the gas flow channel 345 passes through the gap G between the bottom surface of the inner peripheral side of the rectifier 303 and the top surface of the periphery of the hot plate 328, and flows from the side of the wafer W on the hot plate 328 within the processing space K1 toward the wafer W. If the space above the surface of the hot plate 328 is designated as the processing space K1, the gap G for gas flow into the processing space K1 is located at the lower part of the processing space K1.

The aforementioned gap G is connected to one end of the gas flow channel 345. The other end of the gas flow channel 345 is connected to a buffer space K2 below the hot plate 328 within the chamber 300. The volume of the buffer space K2 below the hot plate 328 is larger than the volume of the processing space above the hot plate 328.

The inner circumferential surface of the rectifier 303 extends in a straight line downward from the top 310 of the upper chamber 301.

In one embodiment, the rectifier 303 is a solid body. The material of the rectifier 303 is, for example, a metal such as stainless steel. Furthermore, the top surface of the rectifier 303 is entirely in contact with the bottom surface of the upper chamber 301. More specifically, the rectifier 303 is fixed to the upper chamber 301 with its top surface entirely in contact with the bottom surface of the upper chamber 301, and rises and falls together with the upper chamber 301.

The rectifier 303 descends together with the upper chamber 301 and comes into contact with the lower chamber 302 (specifically, the support ring 337), thereby closing the chamber 300. Dust is suppressed by the contact between the metal rectifier 303 and the metal support ring 337, and can be configured as follows: That is, a resin protrusion can be provided on the surface of the support ring 337 opposite to the rectifier 303, and this resin protrusion contacts the rectifier 303 as it descends. Alternatively, a resin protrusion can be provided on the surface of the rectifier 303 opposite to the support ring 337, and this resin protrusion contacts the support ring 337 as the rectifier 303 descends. In these cases, the smaller the height of the resin protrusion, the better. This is because it reduces the gap between the bottom surface of the rectifier 303 and the top surface of the support ring 337, thus inhibiting the infiltration of sublimates into that gap. The height of the resin protrusion is such that the gap between the bottom surface of the rectifier 303 and the top surface of the support ring 337 is smaller than the shortest distance from the rectifier 303 to the wafer W on the hot plate 328.

Furthermore, the heat treatment apparatus 40 may additionally include a cooling plate (not shown) that functions to cool the wafer W. The cooling plate may move back and forth, for example, between a cooling position outside the chamber 300 and a transfer position where at least a portion is disposed within the chamber 300 and where the wafer W is transferred between the cooling plate and the hot plate 328. Alternatively, the cooling plate may be fixed in a position aligned horizontally with the hot plate 328, and the heat treatment apparatus 40 may include a transfer arm for transporting the wafer W between the cooling plate and the hot plate 328.

<Wafer Processing Using Heat Processing Apparatus 40> Next, an example of wafer processing using heat processing apparatus 40 will be described using Figures 6 to 8. Figures 6 to 8 are diagrams showing the state of heat processing apparatus 40 during wafer processing using heat processing apparatus 40. Furthermore, the following wafer processing is performed under the control of control unit 200.

(Step S1: Adjustment of Chamber Conditions) First, for example, before placing the wafer W toward the hot plate 328, adjust the conditions within the chamber 300. Specifically, adjust the hot plate 328 to a predetermined temperature. Also, adjust the humidity within the processing space K1. The humidity adjustment within the processing space K1 is shown in Figure 6(a) and is performed by exhausting air using the central exhaust section 317, exhausting air using the peripheral exhaust section 323, and expelling processing gas from the nozzle 311.

(Step S2: Wafer Placement) Next, a wafer W with a photoresist coating containing metal is placed on the hot plate 328. Specifically, as shown in FIG6(b), while the peripheral exhaust section 323 continuously exhausts gas and the nozzle 311 continuously ejects processing gas, only the exhaust from the central exhaust section 317 is stopped, and the upper chamber 301 is raised. Then, the wafer W is transported above the hot plate 328 by the transport device 70. Then, the lifting pin is moved up and down, transferring the wafer W from the transport device 70 toward the lifting pin and from the lifting pin toward the hot plate 328, as shown in FIG7(a), thus placing the wafer W on the hot plate 328. Then, the wafer W is adsorbed toward the hot plate 328 through the adsorption hole 330.

(Step S3: PEB Processing) Then, the wafer W on hot plate 328 is subjected to PEB processing.

(Step S3a: Beginning of PEB Processing) Specifically, as shown in Figure 7(b), the upper chamber 301 is lowered, and the rectifier 303 abuts against the support ring 337 of the lower chamber 302, closing the chamber 300. This initiates the PEB processing on the wafer W on the hot plate 328.

From the start of PEB treatment until the first predetermined time has elapsed, the central exhaust section 317 does not exhaust air; instead, air is emitted from the nozzle 311 and exhausted from the peripheral exhaust section 323. Furthermore, the operation of emitting treatment gas from the nozzle 311 and exhausting air from the peripheral exhaust section 323 is performed by supplying gas from the gas supply section 344. For example, the exhaust flow rate L2 from the treatment space K1 via the peripheral exhaust section 323 is controlled to be greater than the flow rate L1 emitted from the nozzle 311 towards the treatment space K1. Consequently, gas corresponding to the flow rate (L2-L1) is drawn into the chamber 300 from outside the chamber 300 through the intake port 343. Then, gas corresponding to the flow rate (L2-L1) is supplied from the gas supply section 344 toward the wafer W on the hot plate 328. The flow rate of the gas supplied from the gas supply section 344 toward the wafer W on the hot plate 328 is approximately equal throughout the circumferential direction. The suction port 343 is located near the bottom of the hot plate 328 and can be referred to as the inlet for the gas to flow into the processing space K1.

When gas is exhausted only from the peripheral exhaust section 323, a flow of processing gas is formed near the surface of wafer W, moving radially towards the periphery of wafer W. In contrast, when gas is exhausted from the central exhaust section 317, the processing gas does not flow along the surface of wafer W, but rather rises towards the center from the periphery. Therefore, the gap between the boundary layer of the gas flow towards the central exhaust section 317 and the surface of wafer W becomes different within the plane of wafer W. This results in uneven evaporation of the coating on wafer W. Then, this uneven evaporation, especially during the initial stages of PEB processing when curing has not yet occurred and evaporation is high, negatively impacts the in-plane uniformity of the film thickness on wafer W.

Therefore, as described above, from the start of PEB processing until the first predetermined time, the central exhaust section 317 does not exhaust gas; instead, gas is emitted from the nozzle 311 and from the peripheral exhaust section 323. The first predetermined time is set to allow the metal-containing photoresist coating on the wafer W to cure to the desired degree. In other words, the first predetermined time is set to allow the dehydration polymerization of the metal-containing photoresist on the wafer W to proceed to the desired degree.

Furthermore, since the gas is supplied by the gas supply section 344, the processing gas is emitted from the nozzle 311 and exhausted from the peripheral exhaust section 323. Therefore, around the wafer W, the gas supplied from the gas supply section 344 toward the wafer W moves toward the exhaust port 324, forming an upward flow. At the same time, the processing gas containing sublimation, which is emitted from the nozzle 311 toward the wafer W and moves along the surface of the wafer W, also moves upward together with the aforementioned upward flow and is discharged to the outside through the exhaust port 324. Therefore, the adhesion of sublimation to the back surface and slope of the wafer W can be suppressed.

Furthermore, during the PEB process, the upper chamber 301 is heated. This is to prevent the sublimate from re-curing and adhering to the upper chamber 301. Also, during the PEB process, the processing gas supplied from the nozzle 311 is heated by the already heated upper chamber 301. Furthermore, during the PEB process, the gas supplied from the gas supply section 344 toward the wafer W on the hot plate 328 is either the gas drawn into the chamber 300 from the suction port 343, the gas heated by the hot plate 328 within the buffer space K2, or the gas heated by that gas. Also, during the PEB process, the gas supplied from the gas supply section 344 toward the wafer W on the hot plate 328 can also be heated by the rectifier 303 heated by the upper chamber 301.

(Step S3b: Start of Central Exhaust) After a first predetermined time has elapsed since the start of PEB processing, while gas continues to be emitted from nozzle 311 and continuously exhausted from peripheral exhaust section 323, exhaust begins from central exhaust section 317. The aforementioned first predetermined time is set as described above to ensure the metal-containing photoresist coating on wafer W is fixed to the desired degree. Furthermore, the information regarding the aforementioned first predetermined time is recorded in a recording unit (not shown).

During this stage, the operation of exhausting gas from the central exhaust section 317, discharging processing gas from the nozzle 311, and exhausting gas from the peripheral exhaust section 323 is performed by supplying gas to the gas supply section 344. For example, the sum of the flow rate L2 of the gas discharged from the processing space K1 by the peripheral exhaust section 323 and the exhaust L3 performed by the central exhaust section 317 is controlled to be greater than the flow rate L1 discharged from the nozzle 311 toward the processing space K1. That is, L2 + L3 > L1 is controlled. As a result, the gas corresponding to the flow rate (L2 + L3 - L1) is drawn into the chamber 300 from outside the chamber 300 through the intake port 343. Then, the gas corresponding to the flow rate (L2 + L3 - L1) is supplied from the gas supply section 344 to the wafer W on the hot plate 328. The flow rate of gas supplied from the gas supply section 344 toward the wafer W on the hot plate 328 is approximately equal throughout the circumferential direction.

By operating the central exhaust section 317, a flow of processing gas is formed near the surface of the wafer W, moving from the outer periphery of the wafer W towards its center. Therefore, the processing gas containing sublimation material near the surface of the wafer W can be discharged through the central exhaust section 317. Furthermore, the exhaust volume obtained from the central exhaust section 317 can be greater than the exhaust volume obtained from the peripheral exhaust section 323. In this case, the processing gas containing sublimation material near the surface of the wafer W is mainly discharged through the central exhaust section 317. Therefore, the adhesion of sublimation material to the back surface and bevel of the wafer W can be further suppressed. Moreover, during the exhaust phase of the central exhaust section 317, the metal-containing photoresist coating solidifies, and the influence of the exhaust gas flow on film thickness variation is relatively small. Therefore, even if air is exhausted from the central exhaust section 317, the impact on the in-plane uniformity of the film thickness is small.

(Step S3c: Cessation of PEB Processing) After a second predetermined time elapses following the start of venting from the central exhaust section 317, the PEB processing ends. Specifically, for example, the upper chamber 301 is raised, and chamber 300 is opened. At this time, venting continues from the central exhaust section 317, and processing gas continues to be ejected from the nozzle 311 and from the peripheral exhaust section 323. The aforementioned second predetermined time is set to allow the metal-containing photoresist coating on the wafer W to cure to the desired degree. Information regarding the aforementioned second predetermined time is recorded in the recording section (not shown).

Furthermore, the first and second specified times mentioned above are set as follows. That is, the proportion of the total PEB processing time during which air is discharged by the central exhaust section 317 is set to 1/20 to 1/2. More specifically, when the total PEB processing time is set to 60 seconds, the period during which air is discharged by the central exhaust section 317 is 3 to 30 seconds. The total PEB processing time refers, for example, the time from when the wafer W is placed toward the hot plate 328, the upper chamber 301 descends and the chamber 300 is set to a closed state, to when the upper chamber 301 rises and the chamber 300 is set to an open state.

(Step S4: Wafer Removal) Then, in the reverse order of placing the wafer W, the wafer W is removed from the hot plate 328 and moved out of the heat treatment apparatus 40.

<Variation Example> In the above example, at the start of PEB processing, the central exhaust unit 317 does not exhaust air, but during PEB processing, the central exhaust unit 317 exhausts air. Instead, at the start of PEB processing, the central exhaust unit 317 exhausts a small amount of air, and during PEB processing, the exhaust from the central exhaust unit 317 is strengthened.

Furthermore, the control unit 200 can control the flow rate of the processing gas supplied by the nozzle 311 to the gas distribution space 313 to increase during the PEB processing period when the gas is discharged from the central exhaust unit 317 or during the period of enhanced discharge from the central exhaust unit 317 (hereinafter referred to as the central exhaust enhancement period). The reason is as follows: The discharge port 312 on the peripheral side and the discharge port 312 on the central side share the gas distribution space 313. Also, during the central exhaust enhancement period, the flow rate of the processing gas discharged from the central side discharge port 312, which is close to the central exhaust unit 317 (specifically, the exhaust port 318), increases. Therefore, during the central exhaust enhancement period, as shown in Figure 9, the exhaust intensity of the central exhaust section 317 results in a situation where, instead of exhausting treatment gas from the peripheral exhaust port 312 towards the treatment space K1, gas from the treatment space K1 is drawn in through the peripheral exhaust port 312. During the central exhaust enhancement period, by increasing the flow rate of treatment gas supplied from the nozzle 311 towards the gas distribution space 313, the aforementioned drawing in of gas from the treatment space K1 through the peripheral exhaust port 312 can be suppressed, that is, the backflow of gas into the nozzle 311 can be suppressed.

<Main Effects of this Embodiment> As described above, in this embodiment, the heat treatment apparatus 40 includes: a hot plate 328 that supports and heats the wafer W; and a chamber 300 that houses the hot plate 328 and has a top portion 310 facing the wafer W on the hot plate 328. Furthermore, the heat treatment apparatus 40 includes: a nozzle 311 disposed on the top portion 310 that ejects processing gas from above toward the wafer W; and a gas supply unit 344 that supplies gas toward the wafer W from a position closer to below the surface of the wafer W. Furthermore, the heat treatment apparatus 40 includes: a central exhaust section 317, located at the top 310 and, in top view, near the center of the wafer W, within a processing space K1 above the hot plate 328 in the chamber 300; and a peripheral exhaust section 323, located at the top 310 and, in top view, extending from the periphery of the wafer W compared to the central exhaust section 317, further venting the processing space K1; and a control section 200. The control section 200 then controls that during heat treatment, the gas ejection section continuously ejects gas, the gas supply section continuously supplies gas, and the peripheral exhaust section continuously vents gas, and that the venting from the central exhaust section during heat treatment is intensified.

Furthermore, the wafer processing related to this embodiment includes: a process of placing a wafer W on a hot plate 328; and a process of heat-treating the wafer W on the hot plate 328. The heat treatment process includes: (A) Expelling processing gas from the top portion 310 of the chamber 300 housing the hot plate 328, facing the wafer W; (B) Supplying gas to the wafer W from a position closer to below the surface of the wafer W; (C) Expelling gas from the top portion 310, located near the center of the wafer W in a top view, into the processing space K1 above the hot plate 328 within the chamber 300; (D) Further expelling gas from the top portion 310, located in a top view, from the periphery of the wafer W, compared to step (C) above the process. In this wafer processing, during heat treatment, the above-mentioned process (A) is continued, as are processes (B) and (D). An upward flow is formed around the wafer W, enhancing the venting of process (C) during heat treatment.

In other words, in this embodiment, the supply of processing gas to the wafer W on the hot plate 328 and the venting operation starting from the periphery of the wafer W located at the top 310 and on the hot plate 328 are continuous during heat treatment. Therefore, the in-plane uniformity of heat treatment can be improved. Thus, contamination of the bevel and back surface of the wafer W caused by sublimation generated from the photoresist coating on the wafer W can be suppressed. Furthermore, the venting operation starting from the periphery of the wafer W located at the top 310 and on the hot plate 328, and the supply of gas to the wafer W from near the lower part of the surface of the wafer W on the hot plate 328, are continuous during heat treatment. Therefore, an upward flow is formed at the periphery of the wafer W. Furthermore, in this embodiment, after heat treatment is performed and the influence of venting from the center of the wafer W on the hot plate 328 (i.e., central venting) on film thickness variation is reduced, central venting with excellent sublimation recovery is performed. Therefore, contamination of the wafer W caused by sublimation generated from the photoresist coating on the wafer W can be further suppressed.

Therefore, according to this embodiment, sublimation from the photoresist coating on the wafer can be suppressed, preventing contamination of the wafer W and improving the in-plane uniformity of the wafer during heat treatment. Furthermore, as described above, with an upward flow, according to this embodiment, the adhesion of sublimation to components (e.g., chamber 300) located around the hot plate 328 can be suppressed.

Furthermore, in this embodiment, the gas supplied by the gas supply unit 344 from a position below the surface of the wafer on the hot plate 328 toward the wafer W on the hot plate 328 is either the gas heated by the hot plate 328 within the buffer space K2 or the gas heated by the hot plate 328. The volume of the buffer space K2 is larger than the volume of the processing space K1. Therefore, 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 surrounding components of the processing space K1 (e.g., the upper chamber 301) may be cooled by the gas, causing the sublimate to solidify. In this embodiment, heated gas can be supplied to the processing space K1 for a longer period of time, thus suppressing the solidification of the sublimate. Furthermore, if unheated gas is supplied from the gas supply section 344 to the wafer W, it may affect the heat treatment of the periphery of the wafer W. In contrast, in this embodiment, the gas supplied from the gas supply section 344 to the wafer W is heated, thus suppressing the deterioration of in-plane uniformity during heat treatment. Additionally, the processing space K1 has a smaller volume, and the heat capacity of the gas inside the processing space K1 is also smaller, so when heated gas is supplied to the processing space K1 for a long period of time, the temperature of the processing space K1 is more easily stabilized.

Furthermore, in this embodiment, the upper chamber 301 is configured to be heatable. Also, the top surface of the rectifier 303 is entirely in contact with the bottom surface of the upper chamber 301. Therefore, the rectifier 303 can be effectively heated by heating the upper chamber 301. Furthermore, the rectifier 303 is a solid body and has a large heat capacity. Therefore, the gas supplied from the gas supply unit 344 can be effectively heated by heating the rectifier 303. Therefore, according to this embodiment, the gas supplied from the gas supply unit 344 can be heated by the already heated upper chamber 301. Therefore, the deterioration of the in-plane uniformity of the sublimate curing and heat treatment caused by the gas supplied from the gas supply unit 344 can be suppressed.

Furthermore, in this embodiment, the rectifier 303 and the upper chamber 301 rise and fall together. Therefore, the rectifier 303 is heated by the upper chamber 301 regardless of its location within the upper chamber 301. That is, even if the upper chamber 301 is raised to open the chamber 300 in order to place the wafer W on the hot plate 328, the rectifier 303 will still be heated by the upper chamber 301. As a result, the rectifier 303 can be maintained at a high temperature. Therefore, according to this embodiment, even when the chamber 300 is closed, the gas supplied from the gas supply unit 344 can be immediately heated by the rectifier 303. Therefore, the in-plane uniformity degradation of the sublimate curing and heat treatment caused by the gas supplied from the gas supply section 344 can be suppressed.

Furthermore, in this embodiment, the inner circumferential surface of the rectifying component 303 extends downward in a straight line from the top 310 of the upper chamber 301. That is, on the inner circumferential side of the rectifying component 303, at the bottom surface of this inner circumferential side, which is above the guide surface, there is no outwardly recessed area. If such a recess existed, gas containing sublimates would be trapped within it, leading to particle generation. In contrast, since the aforementioned recess is absent, particle generation can be suppressed.

Furthermore, regarding the inner circumferential surface of the rectifier 303, the shape extending downward from the top 310 of the upper chamber 301 may not be a perfectly straight line. In other words, the inner circumferential surface of the rectifier 303 may have a certain degree of concavity towards the outside in the area where gas does not stagnate. For example, in order to suppress damage to the upper corner of the inner circumferential surface of the rectifier 303, the upper corner is chamfered, resulting in the inner circumferential surface of the rectifier 303 being concave towards the outside. The concavity formed by the chamfering process to suppress corner damage is very small, so gas will not stagnate, and even if it does stagnate, the impact is small.

Furthermore, in this embodiment, the resin pad 335 is connected to the adsorption hole 330 via the metal component 334 and is connected to the hot plate 328. Therefore, according to this embodiment, compared to the case where the resin pad 335 is directly connected to the hot plate 328, the deterioration of the resin pad 335 caused by heat from the hot plate 328 can be suppressed.

<Confirmation Experiment> In the following Cases 1-3, experiments were conducted to measure the linewidth of photoresist patterns containing metal, and the number of metal atoms on the back and bevels of wafer W. Figures 10-14 show the experimental results for each. Figures 10-12 represent the linewidth thickness of the photoresist pattern using shades of black. The vertical axis of Figure 13 represents the 3σ of the photoresist pattern's linewidth, indicating its in-plane uniformity (CDU). The vertical axis of Figure 14 represents the number of metal atoms per unit area using a logarithmic relationship.

(Case 1) A conventional heat treatment apparatus without a gas supply unit 344 is used. During PEB treatment, gas is exhausted through the central exhaust unit 317 and discharged from the nozzle 311, but not through the peripheral exhaust unit 323. (Case 2) A heat treatment apparatus 40 as shown in Figure 4 is used. Gas is supplied by the gas supply unit 344 from the start to the end of PEB treatment, and gas is exhausted through the peripheral exhaust unit 323 and discharged from the nozzle 311. Furthermore, during PEB treatment, the central exhaust unit 317 does not exhaust gas at all. (Case 3) A heat treatment apparatus 40 as shown in Figure 4 is used. Gas is supplied by the gas supply unit 344 from the start to the end of PEB treatment, and exhaust is achieved through the peripheral exhaust unit 323 and the nozzle 311. Furthermore, gas is exhausted through the central exhaust unit 317 from the beginning to the end of PEB treatment.

Furthermore, in any of Cases 1 to 3, after PEB processing, development and POST processing are performed to form a photoresist pattern containing metal. Then, the linewidth of the photoresist pattern is measured, and the number of metal atoms on the back and bevel of wafer W is measured.

In Case 1, as shown in Figure 10, there is a significant difference in linewidth between the center and periphery of wafer W. In contrast, in Cases 2 and 3, as shown in Figures 11 and 12, there is approximately no difference in linewidth between the center and periphery of wafer W. Furthermore, as shown in Figure 13, in Cases 2 and 3, compared to Case 1, the 3σ (where σ is the linewidth of the photoresist pattern) representing the in-plane uniformity (CDU) of the photoresist pattern linewidth is approximately half.

Furthermore, as shown in Figure 14, in Example 2, compared to Example 1, the number of metal atoms on the back side and beveled surface of wafer W is approximately 1/10. In contrast, in Example 3, compared to Example 1, the number of metal atoms on the back side and beveled surface of wafer W is approximately 1/100. From the above results, it can be seen that, according to this embodiment, the sublimation generated from the photoresist coating on wafer W can be suppressed, thus preventing wafer W from becoming contaminated, and the uniformity within the surface of the heat-treated wafer can be improved.

The embodiments disclosed herein should be considered illustrative in all respects and are not limited thereto. The aforementioned embodiments can be omitted, substituted, or modified in various forms without departing from the scope and intent of the appended invention claims.

40: Heat treatment unit 200: Control unit 300: Chamber 310: Top section 311: Nozzle 317: Central exhaust section 323: Peripheral exhaust section 328: Hot plate 344: Gas supply section K1: Processing space W: Wafer

[Figure 1] Figure 1 is a schematic explanatory diagram showing the internal structure of a coating and developing system that includes the heat treatment apparatus related to this embodiment and serves as a substrate processing system. [Figure 2] Figure 2 is a schematic diagram showing the internal structure of the front side of the coating and developing system. [Figure 3] Figure 3 is a schematic diagram showing the internal structure of the back side of the coating and developing system. [Figure 4] Figure 4 is a schematic longitudinal sectional view showing the structure of the heat treatment apparatus used for PEB processing. [Figure 5] Figure 5 is a schematic bottom view showing the structure of the upper chamber. [Figure 6] Figures 6(a) and (b) are diagrams showing the state of the heat treatment apparatus during wafer processing using the heat treatment apparatus. [Figure 7] Figures 7(a) and (b) show the state of the heat treatment apparatus during wafer processing. [Figure 8] Figure 8 shows the state of the heat treatment apparatus during wafer processing. [Figure 9] Figure 9 shows the effect of the heat treatment apparatus related to this embodiment. [Figure 10] Figure 10 shows the results of the verification experiment. [Figure 11] Figure 11 shows the results of the verification experiment. [Figure 12] Figure 12 shows the results of the verification experiment. [Figure 13] Figure 13 shows the results of the verification experiment. [Figure 14] Figure 14 shows the results of the verification experiment.

Claims (20)

A heat treatment apparatus is provided for heat treating a substrate on which a photoresist coating is formed and which undergoes exposure treatment. The heat treatment apparatus comprises: a hot plate for supporting and heating the substrate; and a chamber for housing the hot plate, the chamber having a top portion with a processing space formed below it, facing the substrate on the hot plate. The chamber further comprises: a gas discharge portion disposed at the top portion for discharging processing gas upwards toward the substrate on the hot plate; a gas supply portion for supplying gas from the side of the substrate on the hot plate, i.e., the lower part of the processing space, toward the substrate on the hot plate; and a central exhaust portion located near the front of the hot plate when viewed from above in the top portion. The aforementioned processing space within the aforementioned chamber is located at the center of the substrate, allowing air to escape; a peripheral exhaust section, viewed from the top, is located on the periphery of the substrate on the aforementioned hot plate, closer to the central exhaust section, further venting air from the aforementioned processing space; and a control section, which, in addition to continuously venting air from the aforementioned gas discharge section, supplying gas from the aforementioned gas supply section, and venting air from the aforementioned peripheral exhaust section during the aforementioned heat treatment, also controls the venting from the aforementioned central exhaust section to be stronger during the aforementioned heat treatment. The gas supply section has: a gas flow channel, provided to surround the side of the aforementioned hot plate; and a rectifier, which directs the gas rising along the aforementioned gas flow channel toward the substrate on the aforementioned hot plate. As in the heat treatment apparatus of claim 1, wherein the aforementioned photoresist is a photoresist containing metal. The heat treatment apparatus of claim 1 or 2, wherein the aforementioned gas flow channel is connected to a buffer space below the aforementioned hot plate in the aforementioned chamber, the volume of the aforementioned buffer space being larger than the volume of the aforementioned treatment space. The heat treatment apparatus of claim 1 or 2, wherein the aforementioned chamber has an upper chamber including the aforementioned top and configured to be freely movable, the aforementioned upper chamber being configured to be heated, and the aforementioned rectifying component being a solid body, the top surface of which is entirely in contact with the bottom surface of the aforementioned upper chamber. The heat treatment apparatus of claim 1 or 2, wherein the aforementioned chamber has an upper chamber including the aforementioned top and configured to be freely movable, the aforementioned upper chamber being configured to be heated, the aforementioned rectifying component being a solid body, its top surface being in contact with the bottom surface of the aforementioned upper chamber, fixed to the aforementioned upper chamber, and moving up and down together with the aforementioned upper chamber. A heat treatment apparatus is provided for heat treating a substrate on which a photoresist coating is formed and which undergoes exposure treatment. The heat treatment apparatus comprises: a hot plate for supporting and heating the substrate; and a chamber for housing the hot plate, the chamber having a top with a processing space formed below it, facing the substrate on the hot plate. The chamber further comprises: a gas discharge section disposed at the top for discharging processing gas towards the substrate on the hot plate from above; a gas supply section for supplying gas to the substrate on the hot plate from the side of the substrate on the hot plate, i.e., below the processing space; and a central exhaust section located near the center of the substrate on the hot plate when viewed from above in the top, allowing the gas to be discharged... The aforementioned processing space within the chamber is vented; a peripheral venting section, viewed from the top, is located closer to the peripheral portion of the substrate on the hot plate than the central venting section, further venting the aforementioned processing space; and a control section, which, in addition to continuously venting by the aforementioned gas venting section, supplying gas by the aforementioned gas supply section, and venting by the aforementioned peripheral venting section during the aforementioned heat treatment, also controls the venting from the aforementioned central venting section to be stronger during the aforementioned heat treatment. The aforementioned hot plate has adsorption holes for adsorbing the aforementioned substrate onto the hot plate itself, and also has a resin pad with a flow channel connected to the aforementioned adsorption holes. The aforementioned resin pad is connected to the aforementioned adsorption holes and to the aforementioned hot plate via a metal component. The heat treatment apparatus of claim 6, wherein the aforementioned metal components have a large diameter. The heat treatment apparatus of claim 6 further comprises: an annular member connected to the aforementioned hot plate via a support column below, wherein the aforementioned resin pad is located below the aforementioned annular member. The heat treatment apparatus of claim 1 or 2, wherein the aforementioned gas discharge section has: a first discharge port located above the periphery of the substrate on the aforementioned hot plate; a second discharge port located above the center of the substrate on the aforementioned hot plate; and a gas distribution space for distributing the supplied treatment gas to the aforementioned first discharge port and the aforementioned second discharge port, wherein the aforementioned control unit controls the flow rate of the aforementioned treatment gas supplied to the aforementioned gas distribution space to increase during the period when the exhaust performed by the aforementioned central exhaust section becomes stronger. A heat treatment apparatus is provided for heat treating a substrate on which a photoresist coating has been formed and which has undergone exposure treatment. The heat treatment apparatus comprises: a hot plate for supporting and heating the substrate; and a chamber for housing the hot plate, the chamber having a top and a processing space for performing the heat treatment formed below it, facing the substrate on the hot plate. The chamber further comprises: a gas discharge section disposed in the top, for discharging the gas from the hot plate. Gas is emitted from above towards the aforementioned substrate on the aforementioned hot plate; a gas supply unit supplies gas from the side of the aforementioned substrate on the aforementioned hot plate, i.e., from the lower part of the aforementioned processing space, towards the aforementioned substrate on the aforementioned hot plate; a central exhaust unit, located near the center of the aforementioned substrate on the aforementioned hot plate when viewed from above, exhausts gas from the aforementioned processing space within the aforementioned chamber; a peripheral exhaust unit, located less than when viewed from above, exhausts gas from the aforementioned top... The aforementioned central exhaust section is located near the periphery of the aforementioned substrate on the aforementioned hot plate, further venting air from the aforementioned processing space; and the control unit, in addition to continuously venting air from the aforementioned gas discharge section, supplying gas from the aforementioned gas supply section, and venting air from the aforementioned peripheral exhaust section during the aforementioned heat treatment, also controls the exhaust from the aforementioned central exhaust section to be stronger during the aforementioned heat treatment, and the aforementioned gas discharge... The unit has: a first discharge port located above the periphery of the substrate on the aforementioned hot plate; a second discharge port located above the center of the substrate on the aforementioned hot plate; and a gas distribution space for distributing the supplied processing gas to the aforementioned first discharge port and the aforementioned second discharge port. The aforementioned control unit controls the flow rate of the processing gas supplied to the aforementioned gas distribution space to increase during the period when the exhaust performed by the aforementioned central exhaust unit becomes stronger. A heat treatment method for heat-treating a substrate having a photoresist coating and for which exposure treatment is performed, the heat treatment method comprising the following steps: a step of placing the substrate on a hot plate that supports and heats the substrate; and a step of heat-treating the substrate on the hot plate, the heat treatment step comprising: (A) a step of expelling a processing gas from a top portion of a chamber housing the hot plate, facing the substrate on the hot plate and forming a processing space for performing the heat treatment therebelow, toward the substrate on the hot plate; (B) a step of supplying gas from the side of the substrate on the hot plate, i.e., the lower part of the processing space, toward the substrate on the hot plate; (C) a step of supplying gas from a position... In the heat treatment, the process of venting air from the processing space in the chamber is performed at the center of the substrate on the hot plate, which is located near the center of the hot plate in the top view; and (D) the process of venting air from the periphery of the substrate on the hot plate, which is located near the periphery of the hot plate in the top view, which is closer to the periphery of the hot plate than in the heat treatment process (C). In the heat treatment, the process of (A) is performed, and the processes of (B) and (D) are performed. An upward flow is formed around the substrate on the hot plate, and the venting of the heat treatment process (C) is enhanced. In the heat treatment process (B), the gas that rises along the gas flow channel that surrounds the side of the hot plate is directed toward the substrate on the hot plate by a rectifier. The heat treatment method of claim 11, wherein the aforementioned photoresist is a metal containing photoresist. As in the heat treatment method of claim 11 or 12, wherein the aforementioned gas flow channel is connected to a buffer space below the aforementioned hot plate in the aforementioned chamber, and the aforementioned (B) process supplies the gas in the aforementioned buffer space heated by the aforementioned hot plate toward the aforementioned substrate on the aforementioned hot plate, wherein the volume of the aforementioned buffer space is larger than the volume of the aforementioned processing space. The heat treatment method of claim 11 or 12, wherein the aforementioned chamber has an upper chamber including the aforementioned top and configured to be freely movable, the aforementioned upper chamber is configured to be heated, the aforementioned rectifier is a solid body, the top surface of which is in contact with the bottom surface of the aforementioned upper chamber and is heated by the heated aforementioned upper chamber, and the aforementioned (B) process supplies the gas heated by the aforementioned rectifier toward the substrate on the aforementioned hot plate. As in the heat treatment method of claim 11 or 12, the aforementioned chamber includes an upper chamber, includes the aforementioned top, and is configured to be freely movable. The aforementioned upper chamber is configured to be heated. The aforementioned rectifier is a solid body, and its top surface is fixed to the aforementioned upper chamber in a form that contacts the bottom surface of the aforementioned upper chamber. It also moves up and down together with the aforementioned upper chamber. Regardless of the vertical position of the heated aforementioned upper chamber, it is heated by the upper chamber. The aforementioned process (B) supplies the gas heated by the aforementioned rectifier to the substrate on the aforementioned hot plate. A heat treatment method for heat-treating a substrate having a photoresist coating and for which exposure treatment is performed, the heat treatment method comprising the following steps: a step of placing the substrate on a hot plate that supports and heats the substrate; and a step of heat-treating the substrate on the hot plate, the heat treatment step comprising: (A) a step of expelling processing gas toward the substrate on the hot plate from a top portion of a chamber housing the hot plate, facing the substrate on the hot plate and forming a processing space for performing the heat treatment therebelow; (B) a step of supplying gas toward the substrate on the hot plate from the side of the substrate on the hot plate, i.e., the lower part of the processing space; and (C) a step of approaching the hot plate from a top view located in the top portion. The process of venting air from the processing space within the aforementioned chamber is located at the center of the aforementioned substrate; and (D) the process of venting air from the peripheral portion of the aforementioned substrate on the aforementioned hot plate, which is closer to the peripheral portion of the aforementioned substrate on the aforementioned hot plate than the aforementioned process (C), is performed further during the aforementioned heat treatment. During the aforementioned heat treatment, the aforementioned process (A) is performed, and the aforementioned processes (B) and (D) are performed, forming an upward flow around the aforementioned substrate on the aforementioned hot plate, thereby enhancing the venting of the aforementioned process (C) during the aforementioned heat treatment. The aforementioned hot plate has an adsorption hole for adsorbing the aforementioned substrate onto the hot plate itself, and also has a resin pad with a flow channel connected to the aforementioned adsorption hole. The aforementioned resin pad is connected to the aforementioned adsorption hole and to the aforementioned hot plate via a metal component. The heat treatment method of claim 16, wherein the aforementioned metal component has a large diameter. As in the heat treatment method of claim 11 or 12, in the aforementioned (A) step, the aforementioned processing gas supplied to the gas distribution space is distributed to a first discharge hole above the periphery of the substrate on the aforementioned hot plate and a second discharge hole above the center of the substrate on the aforementioned hot plate, and discharged through the aforementioned first discharge hole and the aforementioned second discharge hole. During the period when the exhaust is strengthened in the aforementioned (C) step, the flow rate of the aforementioned processing gas supplied to the aforementioned gas distribution space is increased. A heat treatment method for heat-treating a substrate having a photoresist coating and for which exposure treatment is performed, the heat treatment method comprising the following steps: a step of placing the substrate on a hot plate that supports and heats the substrate; and a step of heat-treating the substrate on the hot plate, the heat treatment step comprising: (A) expelling processing gas from a top portion of a chamber housing the hot plate, facing the substrate on the hot plate and forming a processing space for heat treatment therebelow, toward the substrate on the hot plate; (B) supplying gas from the side of the substrate on the hot plate, i.e., the lower part of the processing space, toward the substrate on the hot plate; and (C) venting gas from the processing space within the chamber near the center of the substrate on the hot plate when viewed from above in the top portion. The process (A) and (B) involves further venting air from the periphery of the substrate on the hot plate, which is closer to the periphery of the substrate than in process (C) when viewed from the top. During the heat treatment, process (A) is continued, as are processes (B) and (D), forming an upward flow around the substrate on the hot plate to enhance the venting of process (C) during the heat treatment. In step (A), the aforementioned processing gas supplied to the gas distribution space is distributed to the first discharge hole above the periphery of the substrate on the aforementioned hot plate and the second discharge hole above the center of the substrate on the aforementioned hot plate, and discharged through the aforementioned first discharge hole and the aforementioned second discharge hole. During the period when the exhaust is strengthened in step (C), the flow rate of the aforementioned processing gas supplied to the aforementioned gas distribution space is increased. A readable computer recording medium characterized by: a program that is recorded on a computer controlling the control unit of the aforementioned heat treatment apparatus for executing the heat treatment method of any one of the claims 11 to 19.