JP2016115919A - Thermal treatment apparatus, thermal treatment method and storage medium - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a technique for preventing leakage of sublimate to the outside of a processing container, while ensuring good in-plane uniformity for the thickness of a coating film formed on a wafer, when heat treating the coating film formed on the wafer.SOLUTION: When placing a wafer W coated with a SOC film in a processing container 1, and progressing the crosslinking reaction by heating the wafer W, crosslinking reaction is progressed while performing evacuation from a central exhaust port 34 with a small exhaust flow rate, and evacuation from an outer peripheral exhaust port 31 with a large exhaust flow rate. In other example, evacuation only from the outer peripheral exhaust port 31 is performed from the start of heating of the wafer W, and evacuation from the central exhaust port 34 is performed in addition to evacuation from the outer peripheral exhaust port 31, 20 seconds after start of heating of the wafer W. In yet another example, evacuation only from the outer peripheral exhaust port 31 is performed for 20 seconds after start of heating of the wafer W, thereafter evacuation from the outer peripheral exhaust port 31 is stopped, and evacuation from the central exhaust port 34 is performed.SELECTED DRAWING: Figure 3

Description

  The present invention relates to a heat treatment apparatus, a heat treatment method, and a storage medium for placing a substrate coated with a coating liquid in a processing container and heating the substrate while exhausting the inside of the container.

  In the semiconductor manufacturing process, the resist pattern tends to collapse due to the miniaturization of the circuit pattern, and various countermeasures are being studied. As one of the countermeasures, there is a technique in which a resist pattern is transferred to an underlayer film formed on a semiconductor wafer “hereinafter referred to as“ wafer ””, and the wafer is etched using the underlayer film pattern as an etching mask. . Such a lower layer film is required to have high plasma resistance and high etching resistance. For example, a carbon film [SOC (Spin on Carbon) film] formed by spin coating is used.

  The wafer coated with the SOC film is heated after the coating process to dry the solvent remaining in the coated film and accelerate the crosslinking reaction of the crosslinking agent. At this time, the coated film contains sublimates. Occur. As a heat treatment apparatus that performs such heat treatment, for example, as described in Patent Document 1, the periphery of a hot plate that heats a substrate is closed by a ring shutter, and inert gas is supplied from the periphery of the ring shutter into the processing space. In addition, an apparatus is known that performs heat treatment while exhausting from the upper side of the center of the wafer.

  In recent years, in order to increase the plasma resistance of the SOC film, there has been a request to increase the carbon content, and as a technique for this, heating at a temperature (350 to 400 ° C.) higher than the conventional temperature (300 ° C.) is performed. . However, when the heating temperature is raised, in addition to the sublimated material sublimated from the cross-linking agent contained in the SOC film, low molecular polymers and the like are also scattered, so the amount of the sublimated material increases. Therefore, in order to prevent the sublimate from leaking outside from the processing container, it is required to increase the displacement, but in that case, the airflow that hits the center of the surface of the wafer increases, the coating film rises, There is a concern that the in-plane uniformity of the film thickness deteriorates.

JP 2000-124206 A

  The present invention has been made under such circumstances. The purpose of the present invention is to prevent leakage of sublimates to the outside of the processing container and heat the coating film formed on the substrate. An object of the present invention is to provide a technique capable of obtaining good in-plane uniformity of film thickness.

The heat treatment apparatus of the present invention is a heat treatment apparatus for heat-treating a coating film formed on a substrate.
A mounting portion provided in the processing container and for mounting the substrate;
A heating unit for heating the substrate placed on the placement unit;
An air supply port for supplying air into the processing container, which is provided along the circumferential direction on the outer side of the substrate on the placement unit as seen in a plan view;
An outer peripheral exhaust port for exhausting the inside of the processing vessel provided along the circumferential direction outside the substrate on the placement unit as seen in a plan view;
And a central exhaust port for exhausting the inside of the processing vessel. The central exhaust port is provided above the central portion of the substrate on the mounting portion.

The heat treatment method of the present invention is a method for heat-treating a coating film formed on a substrate.
A step of placing and heating the substrate on a placement portion provided in a processing container;
At least when the set time elapses from the start of heating the substrate, or until the set time when the substrate temperature exceeds the set temperature, at least outside the substrate on the mounting portion in plan view. From the outer peripheral exhaust port provided along the circumferential direction and from the air supply port provided along the circumferential direction outside the substrate on the mounting portion as viewed in a plan view while exhausting the inside of the processing container. Taking gas into the processing vessel;
After the setting time point, at least the inside of the processing container is evacuated from the central exhaust port provided on the upper side of the central portion of the substrate on the placement unit, and the gas is supplied from the supply port into the processing container. And a capturing step.

The storage medium of the present invention is a storage medium that stores a computer program used in an apparatus that places a substrate on which a coating film is formed on a mounting portion in a processing container and heats the coating film,
The computer program includes a group of steps so as to execute the above heat treatment method.

  In the present invention, when a substrate is placed on a placement unit in a processing container and a coating film formed on the substrate is heat-treated by a heating unit, the substrate is placed on the outer side of the substrate on the placement unit along the circumferential direction. And a central exhaust port provided on the upper side of the central portion of the substrate on the mounting portion for exhausting the inside of the processing vessel. For this reason, while the flowability of the coating film is large, it can be relied on at least the exhaust from the outer peripheral exhaust port, and while the generation of sublimation is increased, it can be relied on at least the exhaust from the central exhaust port. Leakage of the sublimate to the outside of the processing container is suppressed, and good in-plane uniformity is obtained with respect to the film thickness.

It is a vertical side view which shows the heat processing apparatus which concerns on embodiment of this invention. It is a vertical side view which shows opening and closing of a ring shutter. It is explanatory drawing which shows the effect | action of the heat processing apparatus which concerns on embodiment of this invention. It is a time chart which shows the exhaust sequence of a heat processing apparatus, and the temperature change of a wafer. It is explanatory drawing which shows the effect | action of the heat processing apparatus which concerns on embodiment of this invention. It is a time chart which shows the exhaust sequence of a heat processing apparatus, and the temperature change of a wafer. It is explanatory drawing which shows the effect | action of the heat processing apparatus which concerns on the other example of embodiment of this invention. It is a time chart which shows the exhaust sequence of a heat processing apparatus, and the temperature change of a wafer. It is explanatory drawing which shows the heat processing apparatus which concerns on the other example of embodiment of this invention. It is a top view which shows the other example of a center exhaust port. It is a vertical side view which shows the heat processing apparatus with which the heating part which concerns on another example was equipped. It is a vertical side view which shows the heat processing apparatus provided with the mechanism which switches on-off of exhaust_gas | exhaustion. It is a top view which shows the mechanism which switches on / off of exhaust_gas | exhaustion. It is a top view which shows the other example of the mechanism which switches on / off of exhaust_gas | exhaustion. It is explanatory drawing which shows the effect | action of the other example of the mechanism which switches on / off of exhaust_gas | exhaustion. It is explanatory drawing which shows the effect | action of the other example of the mechanism which switches on / off of exhaust_gas | exhaustion. It is a top view which shows the other example of the mechanism which switches on / off of exhaust_gas | exhaustion. It is a top view which shows the other example of the mechanism which switches on / off of exhaust_gas | exhaustion. It is a characteristic view which shows the time change of the particle number observed in the reference example. It is a characteristic view which shows the film thickness distribution of the wafer formed in the Example. It is a characteristic view which shows the film thickness distribution of the wafer formed in Example 3-1, 3-2. It is a characteristic view which shows the film thickness distribution of the wafer formed in Example 3-1. It is a characteristic view which shows the film thickness distribution of the wafer formed in Example 3-2. It is a characteristic view which shows the film thickness distribution of the wafer formed in Example 3-3. It is a characteristic view which shows the film thickness distribution of the wafer formed in Example 3-4.

The heat treatment apparatus according to the embodiment of the present invention includes a processing container 1 as shown in FIG. 1, and the processing container 1 includes a bottom structure 2 constituting a bottom, a top plate part 3 serving as a ceiling surface, A ring shutter 5 serving as a side surface. Although not shown, the processing container 1 is placed in a casing which is an exterior body of a module that forms a positive-pressure N ₂ (nitrogen) gas atmosphere.
The bottom structure 2 is supported via a support member 26 on a base 27 corresponding to a bottom surface of a housing (not shown). The bottom structure 2 includes a support base 20 formed of a flat cylindrical body with a recess formed on the center side of the edge 22, and a mounting portion for mounting the wafer W on the recess of the support base 20. A mounting table 21 is fitted and provided. The outer diameter of the support table 20 is set to 350 mm, for example, and the outer diameter of the mounting table 21 is set to 320 mm, for example. The mounting table 21 is provided with a heater 25 made of a resistance heating element that forms a heating unit for heating the wafer W. Accordingly, the mounting table 21 can also be referred to as a heating plate, and the mounting table 21 is referred to as a heating plate 21 in the following description. Further, three support pins 23 that pass through the bottom structure 2 and deliver a wafer W having a diameter of, for example, 300 mm to an external transfer arm (not shown) are provided, for example, at equal intervals in the circumferential direction. The support pin 23 is configured to move up and down by an elevating mechanism 24 provided on the base 27 and project from the surface of the bottom structure 2.

  The top plate portion 3 is constituted by a disk-shaped member having a diameter larger than that of the bottom structure 2. The top plate portion 3 is supported by a ceiling of a housing (not shown), faces the upper surface of the bottom structure 2 via a gap, and its outer edge is positioned outside the outer edge of the bottom structure 2 in plan view. It is provided as follows. A flat cylindrical exhaust chamber 30 is formed inside the top plate portion 3, and the exhaust chamber 30 is formed so that its outer edge is substantially the same as the position of the outer edge of the bottom structure 2. On the bottom surface of the exhaust chamber 30, for example, about 100 outer peripheral exhaust ports 31 are opened along the edge at equal intervals in the circumferential direction. Therefore, the outer peripheral exhaust port 31 is opened at a position outside the outer edge of the wafer W placed on the bottom structure 2. Further, an exhaust pipe (hereinafter referred to as “outer exhaust pipe”) 32 is connected above the exhaust chamber 30, and the outer exhaust pipe 32 has a valve V 1 and a flow rate from the upstream side when the top plate 3 side is the upstream side. The adjusting unit 33 is interposed and connected to a factory exhaust path installed in the factory.

  Further, a central exhaust port 34 is opened at the center of the lower surface side of the top plate portion 3 so that the center thereof coincides with the center of the wafer W placed on the bottom structure 2. Is connected to one end side of a central exhaust pipe 35 provided so as to penetrate the top plate portion 3 and the exhaust chamber 30. The central exhaust pipe 35 is connected to the factory exhaust passage through a valve V2 and a flow rate adjusting unit 38 from the upstream side when the top plate 3 side is the upstream side.

In addition, a ring shutter 5 that is a shutter member for closing a gap between the bottom structure 2 and the top plate portion 3 and forming a processing space is provided around the bottom structure 2. The ring shutter 5 includes an annular portion 50 in which a hollow belt-like member is formed in an annular shape.
Suction ports 51 for sucking external nitrogen gas into the internal space (supply chamber) of the annular portion 50 are formed at equal intervals over the entire circumference at a position closer to the upper side on the outer peripheral surface of the annular portion 50. The air supply ports 52 for supplying nitrogen gas inside the annular portion 50 into the processing container 1 are equally spaced over the entire circumference at a position closer to the lower side on the inner peripheral surface of the annular portion 50. Is formed. An annular ring plate 53 is provided on the lower surface of the ring portion 50, and the ring plate 53 and the ring portion 50 are configured to move up and down integrally by a lifting mechanism 54.

As shown in FIG. 2, the ring shutter 5 is arranged so that the inner peripheral surface of the annular portion 50 faces the edge 22 of the bottom structure 2 with a gap therebetween. 2, the upper surface of the ring shutter 5 is in contact with the lower surface of the peripheral edge of the top plate 3, and the upper surface of the inner edge of the annular plate 53 is in contact with the step of the edge 22 of the bottom structure 2. Thereby, a processing space defined by the bottom structure 2, the top plate 3, the ring shutter 5, and the annular plate 53 is formed. At this time, the air supply port 52 is formed at a position lower than the height of the wafer W on the bottom structure 2. When the ring shutter 5 is further lowered, the ring shutter 5 is lowered to a position indicated by a solid line in FIG. 2, the periphery of the processing space is opened over the entire circumference, and the wafer W is loaded and unloaded. Accordingly, the gap between the bottom structure 2 and the top plate 3 that is opened by lowering the ring shutter 5 corresponds to the loading / unloading port of the wafer W.
In addition, a heater (not shown) for preventing the deposition of sublimates in the wall surface and the top plate portion 3 is embedded in the walls of the top plate portion 3 and the processing container 1 and heated to, for example, 300 ° C.

  Returning to FIG. 1, the heat treatment apparatus includes a control unit 6 including a computer. The control unit 6 has a program storage unit. The program storage unit is configured by placing the wafer W by raising and lowering the support pins 23, raising and lowering the ring shutter 5, heating the heater 25, and opening and closing the valves V1 and V2. A program in which instructions relating to the flow rate adjustment of the flow rate adjustment units 33 and 38 are set is stored. The program is stored in a storage medium such as a flexible disk, a compact disk, a hard disk, an MO (magneto-optical disk), or a memory card and installed in the control unit 6.

  Then, the effect | action of the heat processing apparatus which concerns on embodiment of this invention is demonstrated. In the pre-processing of the heat treatment apparatus, for example, a coating liquid containing a carbon film precursor is applied to the wafer W, and an SOC film as a coating film is formed. When the wafer W is moved above the heating plate 21 by a transfer arm (not shown) with the ring shutter 5 lowered, the wafer W is supported by the support pin 23 below the heating plate 21 by the cooperative action of the transfer arm and the support pin 23 below the heating plate 21. 23. At this time, the power of the heater 25 is controlled so that the temperature of the surface of the heating plate 21 becomes 350 ° C., for example. Then, the ring shutter 5 is raised and the processing container 1 is closed, whereby the processing space is partitioned. Next, the valves V1 and V2 are opened, exhausted from the outer peripheral exhaust port 31 at, for example, an exhaust amount (flow rate) of 25 L (liter) / min, and exhausted from the central exhaust port 34 at an exhaust amount of 5 L / min. Is in a negative pressure state. Then, for example, the support pins 23 are lowered substantially simultaneously with the exhaust of the processing chamber 1 to place the wafer W on the heating plate 21 of the bottom structure 2.

  As shown in FIG. 3, nitrogen gas, which is an inert gas atmosphere in a casing (not shown), which is the atmosphere outside the processing container 1, flows into the annular portion 50 from the suction port 51 provided in the ring shutter 5, and further, the air supply port 52. And flows into the processing container 1. Since the air supply port 52 of the ring shutter 5 is provided at a position lower than the height of the top surface of the bottom structure 2, the nitrogen gas taken into the processing space is formed between the side surface of the bottom structure 2 and the ring shutter 5. It flows upward through the gap. In FIGS. 3, 5 and 7, the wafer W whose surface fluidity is lowered by the crosslinking reaction is hatched.

The airflow that has risen to the outer edge of the upper surface of the bottom structure 2 flows upward as it is and is exhausted to the outer peripheral exhaust port 31, along the upper surface of the bottom structure 2, toward the center of the bottom structure 2, and thereafter Forms an air flow that is exhausted while rising toward the central exhaust port 34, and a gas curtain is formed around the processing space.
FIG. 4 is a graph showing, after the wafer W is placed on the heating plate 21, (1) the exhaust amount of the outer peripheral exhaust port 31 and (2) the central exhaust port 34 and the temperature of the wafer W in association with each other. . The wafer W is heated from the heating start time t0 placed on the heating plate 21, and along with this, the volatilization of the solvent in the coating film (SOC film) is promoted and the crosslinking agent in the coating film crosslinks. The reaction proceeds. For example, for about 20 seconds from the time t0, the cross-linking reaction proceeds and the fluidity is high. During this time, the cross-linking agent and low-molecular components in the coating film volatilize, but as shown in FIG. 3, an exhaust flow toward the outer peripheral exhaust port 31 and an exhaust flow toward the central exhaust port 34 are formed in the processing container 1. Therefore, the volatile components are exhausted on these exhaust streams.

  And, since the gas curtain is formed around the processing atmosphere using the outer peripheral exhaust port 31 and the function of preventing leakage of volatile components to the outside works, the amount of exhaust toward the central exhaust port 34 is reduced. For this reason, the exhaust amount is set to a low flow rate of, for example, 5 L / min. When the exhaust flow rate at the central exhaust port 34 is large and the airflow flowing from the outside of the wafer W to the central exhaust port 34 is too strong, the center of the wafer W rises due to the airflow and streaks are formed on the surface of the wafer W. In-plane uniformity of film thickness is deteriorated. On the other hand, if the exhaust flow rate at the central exhaust port 34 is a small flow rate of 5 L / min, the swell of the film and the formation of streaks can be suppressed.

  After the time t1 when the coating film cross-linking reaction ends (20 seconds after t0), the temperature of the wafer W is further increased and reaches the surface temperature of the heating plate 21, for example, 350 ° C. Thereafter, the wafer W is maintained at this temperature and the remaining thinner and other components are volatilized or sublimated to modify the coating film, and the time t2 that is, for example, 80 seconds after the wafer W heating start time t0. Next, the wafer W is raised from the heating plate 21 by the support pins 23. After the cross-linking reaction is completed, the amount of sublimate increases. However, since the exhaust gas is exhausted from the central exhaust port 34 at a flow rate of 5 L / min, the sublimate mainly enters the central exhaust port 34 from the outer periphery of the bottom structure 2. It is exhausted on the exhaust flow. For this reason, even if the exhaust amount from the outer peripheral exhaust port 31 is as small as 25 L / min, that is, even if the flow of the gas curtain surrounding the processing space is weak, the sublimate does not leak outside the processing container 1.

  If the central exhaust port 34 is not exhausted after the cross-linking reaction, but relying on the exhaust of only the outer peripheral exhaust port 31, the exhaust amount must be considerably increased as can be seen from the data described later, and a heat treatment device is incorporated. In the work area where the installed system is located, there is a risk of exceeding the displacement allocated in the factory.

  FIG. 5 shows a state in which the ring shutter 5 is opened after the wafer W is lifted away from the heating plate 21 at time t2, or at the same time. When the ring shutter 5 is opened and the gap is opened, the atmosphere in the processing container 1 tends to flow from the gap to the outside, but since the exhaust continues from the outer peripheral exhaust port 31 and the central exhaust port 34, The nitrogen gas is drawn into the processing space. For this reason, even when the sublimate generated during the heat treatment of the wafer W is not exhausted, the leakage of the sublimate to the outside of the processing container 1 can be prevented.

  According to the above-described embodiment, when the wafer W coated with the SOC film, which is a coating film, is placed in the processing container 1 and the wafer W is heated to advance the crosslinking reaction, the central exhaust port 34 is used. The exhaust gas is exhausted with a small exhaust amount, and the crosslinking reaction proceeds while exhausting with a large exhaust amount from the outer peripheral exhaust port 31. Therefore, when the fluidity of the SOC film is high, the center of the surface of the wafer W is not exposed to a strong air current, and the bulge of the center can be suppressed, and deterioration of the in-plane uniformity of the film thickness can be avoided. Even after the cross-linking reaction is completed and the generation of sublimates increases, the central exhaust port 34 is exhausted, so even if the exhaust amount of the outer peripheral exhaust port 31 is small, the process is being performed or the ring shutter 5 is opened. In this case, the leakage of the sublimate to the outside of the atmosphere in the processing container 1 can be prevented. There is a strong demand for suppressing the amount of exhaust in the factory from the viewpoint of preventing environmental pollution, and the above-described embodiment is an effective technique in that the amount of exhaust of the entire heat treatment apparatus can be suppressed.

  Another embodiment of the present invention will be described. For example, after exhausting only the outer peripheral exhaust port 31 from the start of heating of the wafer W, and after the crosslinking reaction after a set time has elapsed from the start of heating of the wafer W, in addition to the exhaust from the outer peripheral exhaust port 31, You may make it exhaust from the center exhaust port 34. FIG. FIG. 6 shows a time chart according to another embodiment of the present invention, where (1) shows the exhaust amount of the outer peripheral exhaust port 31 and (2) shows the exhaust amount of the central exhaust port 34, respectively.

  In this embodiment, after the wafer W is supported on the support pins 23, the valve V1 is opened, the exhaust is performed from the outer peripheral exhaust port 31 at a flow rate of 10 L / min, and then or simultaneously the ring shutter 5 is closed. Next, at time t0, the wafer W is placed on the bottom structure 2 and heating is started. After that, for example, 20 seconds have elapsed from the time t0 when the wafer W starts to be heated, and the valve V2 is opened at the time t1 when the cross-linking reaction is finished and the fluidity of the SOC film becomes small. Exhaust is started from the central exhaust port 34 so that the exhaust amount becomes 20 L / min. For the exhaust from the central exhaust port 34, for example, a sequence is set so that the exhaust amount is gradually increased from the time t1 by the flow rate adjusting unit 38 and reaches, for example, 20 L / min when 10 seconds have elapsed from the time t1. It is rare.

  In such an embodiment, during the period from time t0 to t1 when the SOC film cross-linking reaction proceeds, the exhaust from the outer exhaust port 31 is relied on and the central exhaust port 34 is not exhausted. The central part of the surface of the wafer W is not exposed to a strong air flow from the outer periphery toward the upper center, and the formation of the bulge in the central part of the wafer W can be suppressed. Further, during this time period, since the amount of volatile matter and sublimate from the SOC film is small, it is possible to prevent particles from leaking out of the processing container 1 even if only the exhaust from the outer peripheral exhaust port 31 is exhausted. Further, after the time t1 when the SOC reaction of the SOC film is finished, the fluidity of the central surface of the wafer W is low, so even if the surface of the wafer W is exposed to a strong air current, the surface of the film is difficult to rise.

  Therefore, as shown in FIG. 7, in addition to the exhaust from the outer peripheral exhaust port 31, exhaust can be performed with a large exhaust amount from the central exhaust port 34, and the generation of sublimates from the SOC film increases. Can also remove sublimates efficiently. Further, when the ring shutter 5 is opened after the heat treatment of the wafer W is completed, an airflow flowing into the outer peripheral exhaust port 31 from the gap is formed in the same manner as in FIG. 5, so that the atmosphere in the processing container 1 is leaked to the outside. Can be prevented. Since exhaust is performed with a large exhaust amount from the central exhaust port in this manner, the exhaust amount from the outer peripheral exhaust port 31 can be reduced, and as a result, the overall exhaust amount can be reduced.

  Further, for example, when the wafer W is heated, the exhaust from the outer peripheral exhaust port 31 may be switched to the exhaust from the central exhaust port 34. FIG. 8 shows a time chart in still another embodiment of the present invention, where (1) shows the exhaust amount of the outer peripheral exhaust port 31, and (2) shows the exhaust amount of the central exhaust port 34, respectively. . In this embodiment, after the wafer W is supported by the support pins 23, first, exhaust is started at an exhaust rate of 10 L / min from the outer peripheral exhaust port 31, and then or simultaneously, the ring shutter 5 is closed. Next, at time t0, the wafer W is placed on the bottom structure 2 and heating is started. Thereafter, exhaust is performed only from the outer peripheral exhaust port 31 for 20 seconds from the time t0 when the heating of the wafer W is started to time t1, and then after 20 seconds from the time when the heating of the wafer W is started, the crosslinking reaction is completed, and the flow of the SOC film At time t1 when the performance becomes small, the exhaust amount of the outer peripheral exhaust port 31 is gradually reduced, and for example, exhaust is stopped 10 seconds after time t1. On the other hand, the exhaust amount of the central exhaust port 34 is gradually increased from time t1, and for example, exhaust is performed at an exhaust amount of 30 L / min 10 seconds after time t1.

  Also in such an embodiment, during the period from time t0 to time t1 when the SOC film cross-linking reaction proceeds, the central portion of the surface of the wafer W is not exposed to a strong air flow from the outer periphery to the center, and the wafer is exposed. The formation of the bulge in the central portion of W can be suppressed. Further, during this time period, since the amount of volatile matter and sublimate from the SOC film is small, it is possible to prevent particles from leaking out of the processing container 1 even if only the exhaust from the outer peripheral exhaust port 31 is exhausted. Further, after time t1 when the SOC film crosslinking reaction is completed, even if the surface of the wafer W is exposed to a strong air current, the surface of the film is unlikely to rise. Therefore, exhaust can be performed with a large exhaust amount from the central exhaust port 34, and the sublimate can be efficiently removed even under a situation where the generation of sublimate from the SOC film increases. In addition, when the ring shutter 5 is opened after the heat treatment of the wafer W is completed, the sublimate is sufficiently exhausted by exhausting from the central exhaust port 34 in advance, thereby leaking the sublimate to the outside of the processing container 1. Can be suppressed.

  Here, when executing the sequence shown in FIGS. 6 and 8, the timing of starting the exhaust of the central exhaust port 34 may be managed by the elapsed time from the time t0 when the heating of the wafer W is started. It is also possible to detect and manage that the temperature is the set temperature. That is, it can be set, for example, as the start time of exhaust of the central exhaust port 34 at the time when the set time has elapsed from the start of heating of the wafer W or when the temperature of the wafer W exceeds the set temperature. The temperature of the wafer W can be detected by providing a temperature detection unit such as a thermocouple on the heating plate 21, for example.

  And the set time is the time when the crosslinking reaction of the coating film is finished, but the term “the time when the crosslinking reaction is finished” as referred to in the claims means that the fluidity of the coating film is common sense from any viewpoint. Included even if it is in a state where it is determined that the cross-linking reaction is not completed and is a little later than the time when the cross-linking reaction is completed, for example 1 second, or even 2 seconds before the time when the cross-linking reaction is completed. . Further, for example, in Example 5 described later, exhaust is performed by setting the exhaust amount of the central exhaust port 34 to 25 L / min 20 seconds after the start of heating, but the start of this exhaust is slightly less than 20 seconds after the start of heating. If performed before, the film thickness at the center of the wafer W is raised. Therefore, when the central exhaust port 34 is exhausted at a timing of 25 L / min or later after a certain timing, the time after the timing at which the film thickness at the center of the wafer W clearly rises is “the crosslinking reaction is completed. It can also be said that it is “time.”

Further, after 20 seconds have elapsed from the heating of the wafer W and the crosslinking reaction has been completed, it is preferable to exhaust the sublimate efficiently. Therefore, it is preferable that the exhaust amount of the central exhaust port 34 is larger than the exhaust amount of the outer peripheral exhaust port 31. However, whether it is appropriate to increase the exhaust amount of the central exhaust port 34 or the exhaust amount of the outer peripheral exhaust port 31 depends on the kind of coating film, the viscosity, the film thickness, and the processing container. It depends on the shape of 1.
Further, during the heat treatment of the wafer W, the exhaust amount of the central exhaust port 34 or the outer peripheral exhaust port 31 is not limited to be constant, and the exhaust amount may be changed depending on the elapsed time from the start of heating. For example, the exhaust amount of the outer peripheral exhaust port 31 is set to 25 L / min and the exhaust amount of the central exhaust port 34 is set to 5 L / min from the start of heating of the wafer W, and the exhaust of the outer peripheral exhaust port 31 is exhausted 20 seconds after the start of heating of the wafer W. The amount may be changed to 10 L / min, and the exhaust amount of the central exhaust port 34 may be changed to 20 L / min. Further, the exhaust amount may be gradually increased or decreased as time passes. It should be noted that the exhaust amount of the central exhaust port 34 and the outer exhaust port 31 once increases and then decreases. Alternatively, a case where the engine displacement once decreases and then increases is also included in “the displacement increases or decreases with time”.

  In the heat treatment apparatus of the present invention, as shown in FIG. 9, in the processing container 1, the air supply port 72 of the external atmosphere is provided at a position higher than the wafer W, and the outer peripheral exhaust port 71 is at a position lower than the wafer W. May be provided. For example, a plurality of air supply ports 72 may be provided in the circumferential direction at a position near the ring shutter 75, and a plurality of outer peripheral exhaust ports 71 may be provided in the circumferential direction on the base 27 that supports the bottom structure 2. In FIG. 9, the air supply port 72 may be opened at a position on the lower surface of the top plate 3 and facing the outer peripheral exhaust port 71 instead of being provided on the upper side of the ring shutter 75. In this case, an air supply path is formed in the top plate portion 3, and for example, the base end side is opened on the side surface of the top plate portion 3. If comprised in this way, the curtain of the exhaust flow which goes below from the top-plate part 3 in the outer side of the bottom part structure 2 will be formed. The present invention is not limited to a heat treatment apparatus that heats the SOC film, and may be a heat treatment apparatus that performs heat treatment after applying a coating liquid used for an antireflection film, for example.

  Further, the central exhaust port 34 is not limited to the configuration in which one central exhaust port 34 is provided in the lower surface side central portion of the top plate portion 3 in the processing container 1. For example, as shown in FIG. 10A, when viewed in plan, a plurality of, for example, eight circular exhaust ports 81 are provided at equal intervals on the circumference of a circle centered on the central portion of the wafer W. The exhaust port 34 may be used. Further, as shown in FIG. 10B, the slit-like opening portions 82 forming the central exhaust port 34 may be provided at four locations shifted by 90 degrees about the central portion of the wafer W as viewed in a plan view. Good. Alternatively, as shown in FIG. 10C, when viewed in plan, for example, eight rectangular openings 83 may be arranged along a square centered on the center of the wafer W to form the central exhaust port 34. Then, as shown in FIG. 10D, four triangular openings 84 may be arranged at equal intervals in the circumferential direction around the center of the wafer W as the central exhaust port 34. Furthermore, as shown in FIG. 10E, concentric double circular slits 85a and 85b centering on the central portion of the wafer W (in detail, a bridging portion exists in the middle of the slits 85a and 85b). Therefore, the central exhaust port 34 may be constituted by a circular arc shape). As described above, the central exhaust port 34 is arranged symmetrically in the circumferential direction with respect to the upper center of the wafer W, so that it is higher from each direction of the peripheral edge of the wafer W due to the external atmosphere supplied to the processing chamber 1. A uniform air flow toward the upper center of the wafer W can be formed with uniformity. Accordingly, the sublimate can be collected efficiently, and the same effect can be obtained.

  Furthermore, when the installation position of the outer peripheral exhaust port 31 is close to the center of the top plate part 3 of the processing container 1, the sublimate collection efficiency increases, but the film thickness uniformity tends to deteriorate. On the other hand, when the installation position of the outer peripheral exhaust port 31 is far from the center of the top plate part 3 of the processing container 1, the film thickness uniformity is improved, but the sublimate collection efficiency is lowered. Further, when the opening diameter of the outer peripheral exhaust port 31 is reduced, the flow velocity is increased and the sublimate collection efficiency is increased. Therefore, the position of the outer peripheral exhaust port 31 is preferably arranged on the circumference of a diameter of 280 to 320 mm, for example, 300 mm, centered on the center of the top plate portion 3 of the processing container 1. 3 mm, for example 2 mm, is preferred.

  The heating unit that heats the wafer W may be a heat radiation source that heats the wafer W by irradiating light from a light source such as an LED. As such an example, instead of the heating plate 21 of the bottom structure 2, for example, a configuration in which an LED array 91 that forms a heat radiation source is provided on the bottom surface of the recess of the support base 20 as shown in FIG. The LED array 91 is surrounded by a reflecting plate 93 that is, for example, a copper (Cu) plate plated with gold over its entire circumference, and reflects light traveling in a direction different from the irradiation direction (upward in FIG. 11). It is configured so that radiation light can be extracted effectively.

  A transmission plate 92 made of, for example, quartz is provided above the LED array 91 to partition the atmosphere in which the LED array 91 is placed from the processing atmosphere. Further, inside the transmission plate 92 is provided a cooling line 94 which is a flow path for passing cooling water such as cooling water, and the transmission plate 92 is used for cooling the wafer W after the heat treatment. Also serves as a cooling member. The cooling line 94 is connected to a chiller 95 and a circulation pump 96 provided outside the processing vessel 1, and the refrigerant flowing through the cooling line is adjusted to a set temperature by the chiller 95 and permeated by the circulation pump 96. It is sent into the plate 92.

In this example, after the wafer W is delivered to the support pins 23, the wafer W is lowered and moved to a height (heating height position) at which the wafer W is subjected to heat treatment. When the wafer W is held at the heating height position, the LED array 91 irradiates infrared light, which is radiation light in the absorption wavelength region of the wafer W, toward the wafer W, and the wafer W is subjected to predetermined heat treatment. Heated to temperature. Therefore, in this example, the support pin 23 corresponds to the mounting portion.
Further, the LED array 91 may be provided on the upper side of the wafer W placed on the bottom structure 2, and the wafer W placed on the bottom structure 2 may be irradiated with light from above to heat the wafer W.

Next, still another embodiment of the present invention will be described. This embodiment is an example in which an ejector is used as a mechanism for switching the exhaust of the central exhaust pipe 35 on and off. As shown in FIG. 12, the central exhaust pipe 35 extends from the central exhaust port 34 along the upper surface of the top plate portion 3 via the buffer chamber 34a, and is connected to the suction port of the ejector 101. The upper surface side of the top plate portion 3 is formed as a partitioned space 301 that is covered with a cover body 300 and partitioned from the outside. In this partitioned space 301, the ejector 101 and its peripheral portion are arranged. The top plate 3 is provided with a heater 302, and the heater 302 allows the partition space 301 to prevent sublimation contained in the exhaust flow in the outer exhaust pipe 32 and the central exhaust pipe 35, for example, 300. It is heated to a temperature of ° C.
FIG. 13 is a plan view showing the upper surface side of the top plate portion 3, and reference numeral 321 denotes an outer peripheral exhaust passage composed of a duct. The duct 321 communicates with the exhaust chamber 30 through an opening formed in the top plate portion 3, and the upstream side surrounds the buffer chamber 35 and is linearly arranged in the partition space 301 as shown in FIG. 13. ing.

  The ejector 101 and its peripheral parts will be described with reference to FIG. When the downstream side of the outer peripheral exhaust passage 321 is the front side and the upstream side is the rear side, an air supply pipe 102 that is a supply pipe of air that is the suction gas of the ejector 101 is located on the right side in FIG. It extends from the front side toward the rear side. The valve 99 in the drawing constitutes an air supply / stop mechanism. The air supply pipe 102 is configured as a heat exchanging portion 103 by forming a curved path on the rear side of the central exhaust port 34. The heat exchanging unit 103 is made of, for example, a metal material having good thermal conductivity, and a heating channel 104 is formed inside. The heating channel 104 extends rearward from a position on the front right side when the heat exchange unit 103 is viewed from the front side, and then bends a plurality of times to the left and right, and opens to the left side of the front surface of the heat exchange unit 103. One end of the exhaust pipe 106 is connected to the left end of the heating channel 104. The air supplied to the heating channel 104 is at room temperature, and the temperature is raised to a temperature at which the sublimate can be prevented from adhering by the heat of the heater 302. Therefore, the heater 302 and the heat exchange unit 103 constitute a gas temperature control mechanism.

  The ejector 101 is composed of a T-shaped piping structure in which a converging pipe line 101B is connected from a side to a gas pipe line 101A that extends linearly. The downstream end of the air supply pipe 102 is connected to one end side of the gas pipeline 101A, and the other end side (discharge side) of the gas pipeline 101A is drawn into the factory via the exhaust pipe 106 and the intermediate duct 105. It is connected to an exhaust duct 100 that is a downstream exhaust passage. The exhaust duct 100 is always exhausted by factory power, which is exhaust power. Further, the downstream end of the central exhaust pipe 35 is connected to the confluence pipe line 101 </ b> B that forms the suction port of the ejector 101. Further, the ejector 101 and the central exhaust pipe 35 are also heated by the heat of the heater 302 in the same manner as the heat exchange unit 103.

  The operation of the above-described embodiment will be described along the time chart shown in FIG. First, after the heating of the wafer W is started, only the outer peripheral exhaust port 31 is evacuated, and after the cross-linking reaction after a set time has elapsed from the start of heating of the wafer W, in the example of FIG. At time t1 when the fluidity of the SOC film becomes small, exhaust is performed from the central exhaust port 34 in addition to exhaust from the outer peripheral exhaust port 31. When starting the exhaust from the central exhaust port 34, the valve 99 is opened, the supply of air is started from the air supply pipe 102, and the air is supplied to the ejector 101 through the heat exchange unit 103.

Air passes through the heat exchanging section 103 and is heat-exchanged with the atmosphere in the compartment space 301 heated by the heater 302, and a sufficient time until the sublimate in the exhaust flow that joins thereafter does not adhere. Heated. The heated air flows as gas for suction through the gas conduit 101A of the ejector 101, the inside of the merge conduit 101B of the ejector 101 becomes negative pressure, and the gas on the side of the central exhaust pipe 35 is drawn. The atmosphere in the processing container 1 is exhausted from 34. The atmosphere in the processing container 1 drawn into the merging pipe line 101B merges with the heated air flowing through the gas pipe line 101A, and is then exhausted to the exhaust duct 100 via the exhaust pipe 106 and the intermediate duct 105. .
As described above, since the air is heated, the temperature of the exhaust flow that merges from the merge pipe 101B does not decrease, and the precipitation of sublimates contained in the exhaust flow is suppressed on the exhaust duct 100 side.

Thereafter, when the exhaust from the central exhaust port 34 is stopped, the valve 99 is closed and the supply of air from the air supply pipe 102 is stopped. As a result, air does not flow through the gas pipe 101A, and the suction action in the merge pipe 101B disappears, and the exhaust from the central exhaust pipe 34 stops.
According to this embodiment, there are the following effects. Since the temperature above the heat treatment device becomes high due to the influence of the heat treatment, for example, when a valve device is provided and the exhaust of the central exhaust port 34 is switched on and off, a valve that can be driven at a high temperature is required. However, such a valve is large and heavy. On the other hand, if the structure which provides the ejector 101 in the center exhaust pipe 35 is employ | adopted, it can be set as a simple and small apparatus structure.

  Here, the heat treatment apparatus is exhausted by factory power, but is always exhausted by factory power. Therefore, the exhaust duct 100 is always at a negative pressure, and when the supply of air is stopped to stop the exhaust, the central exhaust pipe 35 connected to the ejector 101 depending on the magnitude of the exhaust amount of the factory power. Tends to be negative pressure, and there is a risk that exhaust will continue slightly from the central exhaust port 34.

  Therefore, it is advantageous to connect a dummy pipe to the exhaust duct 100 to suppress the negative pressure in the central exhaust pipe 35. For example, as shown in FIG. 14, the dummy pipe 107 is connected downstream of the connection position of the intermediate duct 105 through which the exhaust flow exhausted from the central exhaust port 34 flows in the exhaust duct 100. Further, an air operation valve 108 is provided on the upstream side of the air supply pipe 102 so that the pipe for supplying air is switched between the air supply pipe 102 and the dummy pipe 107.

  An ejector 110 having the same configuration as that of the ejector 101 is provided in the middle of the dummy pipe 107 so that air flowing through the dummy pipe 107 flows through the gas pipe 110A of the ejector 110, and the merge pipe 110B of the ejector 110 is connected. An end (suction port) is opened, and an atmosphere outside the flow path through which the exhaust flow passes, for example, an atmosphere outside the compartment space 301 is taken in.

  When exhausting from the central exhaust port 34, the air operation valve 108 is switched, and air is supplied to the heat exchanging unit 103 side so that exhaust from the central exhaust port 34 is performed as shown in FIG. Is called. Thereafter, when stopping the exhaust from the central exhaust port 34, the air operation valve 108 is switched to stop the supply of air to the heat exchanging portion 103 side and to start supplying air to the dummy pipe 107 side. As a result, as shown in FIG. 16, the external atmosphere is drawn from the merging pipe line 110 </ b> B of the ejector 110 provided in the dummy pipe 107 and flows into the exhaust duct 100. Therefore, when the exhaust duct 100 becomes negative pressure when the exhaust from the central exhaust port 34 is stopped, the atmosphere from the dummy pipe 107 side flows and the negative pressure in the exhaust duct 100 is suppressed. Intake of exhaust on the pipe 106 side is suppressed.

  When the dummy ejector 110 is combined with the dummy pipe 107 in this way and the dummy is drawn when the exhaust flow is stopped, the exhaust flow rate when the exhaust flow is exhausted by the exhaust duct 100 using the ejector 101 is as follows. The exhaust flow rate when pulling in the dummy is aligned. Therefore, if the exhaust flow rate suitable for the exhaust flow is set on the factory power side, the generation of negative pressure in the central exhaust pipe 35 can be suppressed with high certainty when the air supply is switched to the dummy pipe 107 side. Accordingly, the outflow of the processing atmosphere from the central exhaust port 34 can be suppressed. For example, in this configuration, when the suction action of the ejector 101 is stopped, the flow rate of the exhaust from the central exhaust port 34 is preferably suppressed to a flow rate of 2 L / min or less.

  In addition, as shown in FIG. 17, a dummy pipe 107 is provided, and a pressure loss portion 101C is provided in a portion of the merging pipe line 101B in the ejector 101 connected to the central exhaust pipe 35, so that the central exhaust is more than the ejector 110 on the dummy pipe 107 side. The ejector 101 on the tube 35 side may be configured to have a higher pressure loss. The pressure-loss portion 101C is configured, for example, by reducing the diameter of a part of the flow path (with a smaller diameter than the front and rear portions). As a result, when the air operation valve 108 is further switched and the suction of the exhaust flow on the central exhaust pipe 35 side is stopped, the atmosphere on the dummy pipe 107 side is more easily drawn, so the outflow of the processing atmosphere from the central exhaust port 34 is prevented. Can be suppressed. The pressure loss portion 101C is not limited to the position shown in FIG.

Further, as shown in FIG. 18, a check valve 109 may be provided in the exhaust pipe 106. In this case, the check valve 109 may be configured not to flow unless the pressure difference between the upstream side and the downstream side of the check valve 109 is large. By configuring in this way, when the suction action of the ejector 101 is stopped, the gas on the ejector 101 side is prevented from flowing through the check valve, so that the same effect can be obtained. ]

  Examples carried out to verify the effects of the embodiment of the present invention will be described. The wafer W coated with the SOC film was heated at 350 ° C. using the heat treatment apparatus shown in the embodiment of the present invention. Until the wafer W was heated and removed from the processing container 1, the central exhaust port 34 and the outer peripheral exhaust port 31 were evacuated, and the number of particles of 100 nm or more was counted outside the processing container 1. The exhaust flow rate of the central exhaust port 34 and the exhaust amount of the outer peripheral exhaust port 31 in each example were set as follows. The wafer W was loaded into the processing container 1 and placed on the bottom structure 2, and then heated for 80 seconds, and then the ring shutter 5 was opened and the wafer W was taken out.

(Example 1-1)
The exhaust amount of the outer peripheral exhaust port 31 is set to 20 L / min, the exhaust amount of the central exhaust port 34 is set to 10 L / min, and the outer peripheral exhaust port is from the loading of the wafer W into the processing container 1 to the removal thereof. 31 and the central exhaust port 34 were exhausted.
(Example 1-2)
It was set in the same manner as in Example 1-1 except that the exhaust amount of the outer peripheral exhaust port 31 was set to 25 L / min and the exhaust amount of the central exhaust port 34 was set to 5 L / min.
(Example 1-3)
The exhaust amount of the outer peripheral exhaust port 31 is set to 10 L / min, and after 20 seconds from the start of heating of the wafer W, exhaust is started at an exhaust amount of 20 L / min from the central exhaust port 34 (in addition to the exhaust of the outer peripheral exhaust port 31). Except that the central exhaust port 34 is exhausted), the same setting as in Example 1-1 was performed.
(Example 1-4)
It was set in the same manner as in Example 1-3 except that the exhaust amount of the outer peripheral exhaust port 31 was set to 15 L / min and the exhaust amount of the central exhaust port 34 was set to 15 L / min.
(Example 1-5)
It was set in the same manner as in Example 1-3 except that the exhaust amount of the outer peripheral exhaust port 31 was set to 5 L / min and the exhaust amount of the central exhaust port 34 was set to 25 L / min.
(Reference example)
In addition, an example in which processing was performed in the same manner as in Example 1-1 except that the wafer W was heat-treated while performing exhaust using only the outer peripheral exhaust port 31 without exhausting from the central exhaust port 34. It was set as a reference example. In the reference example, the flow rate of exhaust gas from the outer peripheral exhaust port 31 was set to 0, 5, 10, 30, 50, and 60 L / min.

  FIG. 19 is a characteristic diagram showing the relationship between the elapsed time from the loading of the wafer W and the observed number of particles when the flow rate of exhaust from the outer peripheral exhaust port 31 in each reference example is set to each flow rate. When the flow rate of the exhaust gas at the outer peripheral exhaust port 31 is 0 L / min, that is, when exhaust is not performed, it can be seen that the atmosphere including the sublimate flows out from the suction port before the ring shutter 5 is opened. In addition, when the flow rate of exhaust was set to 0 to 50 L / min, particles were observed after opening the ring shutter 5, and when the flow rate was set to 60 L / min, the ring shutter 5 was opened. Later, no particles were observed. Therefore, when exhaust is performed only from the outer peripheral exhaust port 31, it can be said that the exhaust flow rate needs to be set to 60 L / min or more in order to prevent leakage of sublimates when the wafer W is taken out.

  On the other hand, in Examples 1-1 and 1-2, particles were not confirmed not only during the heat treatment but also after the ring shutter 5 was opened. Therefore, it can be understood that the leakage of sublimates can be suppressed by performing exhaust using both the central exhaust port 34 and the outer peripheral exhaust port 31. Similarly, in Examples 1-3 to 1-5, particles were not confirmed not only during the heat treatment but also after the ring shutter 5 was opened. Even when evacuation is started from the central exhaust port 34 after 20 seconds from the start of heating of the wafer W, the sublimate can be sufficiently removed, and the leakage of the sublimate when the ring shutter 5 is opened can be suppressed. I can say that.

FIG. 20 shows the film thickness distribution on the diameter of the wafer W subjected to the heat treatment in Example 1-2 and Example 1-5. The horizontal axis represents the distance from the center of the wafer W diameter, and the vertical axis represents the distance. It is a characteristic view showing the film thickness of the SOC film.
According to this result, the swelling of the film at the center of the wafer W is suppressed,
The difference between the maximum value and the minimum value of the SOC film thickness was 0.73 nm in Example 1-2 and 0.71 nm in Example 5. Therefore, according to the embodiment of the present invention, it can be said that good in-plane uniformity is ensured with respect to the film thickness of the heat-treated wafer W.
[Example 2]

In the central exhaust mechanism, the presence or absence of a sublimated material due to the presence or absence of the heat exchange unit 103 was examined.
[Example 2-1]
The heat treatment apparatus shown in FIG. 1 was tested with the exhaust on / off mechanism shown in FIGS. The heating temperature of the heating plate 21 was set to 400 ° C., the heating temperature of the processing container 1 was set to 300 ° C., the heating time of the wafer W was set to 60 seconds, and the cooling time after heating was set to 24 seconds. Further, the flow rate of the central exhaust port 34 was set to 40 L / min, and the exhaust flow rate of the outer peripheral exhaust port 31 was set to 20 L / min.
[Comparative example]
A test was performed using the same heat treatment apparatus and exhaust on / off mechanism as in Example 2 except that the heat exchange unit 103 was not provided and air was supplied from the air supply pipe 102 to the ejector 101. The heating temperature of the heating plate 21 was set to 450 ° C., the heating temperature of the processing container 1 was set to 350 ° C., the heating time of the wafer W was set to 60 seconds, and the cooling time after heating was set to 24 seconds. Further, the flow rate of the central exhaust port 34 was set to 20 L / min, and the exhaust flow rate of the outer peripheral exhaust port 31 was set to 20 L / min.

In each of Example 2-1 and Comparative Example, after processing 2500 wafers W, the adhesion of sublimate in the ejector 100 was examined. In the comparative example, clogged sublimates were confirmed, and the exhaust flow rate was reduced to about 40% of the flow rate before the test. On the other hand, in Example 2-1, no sublimate or clogging was observed, and the exhaust flow rate was substantially 100% of the flow rate before the test.
According to this result, when the central exhaust mechanism is provided, it can be said that by supplying the air heated by the heat exchanging unit 103 to the ejector 101, it is possible to suppress the attachment of sublimates.

[Example 3]
In order to verify the effect of the heat treatment apparatus provided with the exhaust on / off mechanism, heat treatment was performed according to the following examples, and the film thickness uniformity was examined.
[Example 3-1]
After the coating liquid A was applied to the wafer W, heat treatment was performed using the heat treatment apparatus shown in FIG. 1 according to the time chart shown in FIG. The flow rate of the central exhaust port 34 was set to 20 L / min, the exhaust flow rate of the outer peripheral exhaust port 31 was set to 20 L / min, and exhausting was started from the central exhaust port 34 20 seconds after the start of heating.
[Example 3-2]
The heat treatment was performed in the same manner as in Example 3-1, except that the heat treatment apparatus shown in FIG. 1 was connected to the exhaust on / off mechanism shown in FIGS.
[Example 3-3]
The coating liquid B was applied to the wafer W, and processing was performed in the same manner as in Example 3-1, except that exhausting was started from the central exhaust port 34 after 15 seconds from the start of heating.
[Example 3-4]
The heat treatment was performed in the same manner as in Example 3-3, except that the heat treatment apparatus shown in FIG. 1 was connected to the exhaust on / off mechanism shown in FIGS.

[Test results]
FIG. 21 shows the film thickness distribution on the diameter of the wafer W subjected to the heat treatment in Example 3-1 and Example 3-2. The horizontal axis represents the distance from the center of the wafer W diameter, and the vertical axis represents the SOC. It is the characteristic view which showed the film thickness of the film | membrane. FIGS. 22 to 25 are characteristic diagrams showing the film thickness distribution of the wafer W subjected to the heat treatment in Examples 3-1 to 3-4 by contour lines.

In FIG. 21, the difference between the maximum value and the minimum value of the film thickness in the diameter of the wafer W was 1.03 nm in Example 3-1, and 0.52 nm in Example 3-2. 22 to 25, the value of the film thickness at 80 points on the wafer W was used, and in Examples 3-1 and 3-2, the difference between the maximum value and the minimum value of the film thickness and 3σ were measured. . Moreover, about Example 3-3 and 3-4, 3 (sigma) was measured.
In Example 3-1, the difference between the maximum value and the minimum value of the film thickness and 3σ were 1.47 nm and 0.94 nm, respectively. In Example 3-2, the maximum value of the film thickness was The difference from the minimum value and 3σ were 0.77 nm and 1.23 nm, respectively. In Example 3-3, 3σ was 3.03 nm, but in Example 3-4, 3σ was 2.01 nm. Therefore, the difference between the maximum value and the minimum value of the film thickness and 3σ are both smaller in Example 3-2 than in Example 3-1, and the uniformity of the film thickness is good. In Example 3-4, 3σ was smaller than that of −3, and the film thickness uniformity was good.
According to this result, it can be said that the uniformity of the film thickness is further improved by switching the central exhaust on and off using the exhaust on / off mechanism.

DESCRIPTION OF SYMBOLS 1 Processing container 2 Bottom structure 3 Top plate part 4 Vacuum pump 5 Ring shutter 6 Control part 21 Heating plate 30 Exhaust chamber 31 Outer periphery exhaust port 34 Central exhaust port W Wafer

Claims (19)

In the heat treatment apparatus for heat-treating the coating film formed on the substrate,
A mounting portion provided in the processing container and for mounting the substrate;
A heating unit for heating the substrate placed on the placement unit;
An air supply port for supplying air into the processing container, which is provided along the circumferential direction on the outer side of the substrate on the placement unit as seen in a plan view;
An outer peripheral exhaust port for exhausting the inside of the processing vessel provided along the circumferential direction outside the substrate on the placement unit as seen in a plan view;
A heat treatment apparatus, comprising: a central exhaust port which is provided above the central portion of the substrate on the mounting portion and exhausts the inside of the processing container. One of the air supply port and the outer peripheral exhaust port opens at a position higher than the substrate, and the other opens at a position lower than the substrate,
The heat treatment apparatus according to claim 1, wherein an airflow curtain is formed so as to surround the substrate by an airflow flowing from the air supply port to the outer peripheral exhaust port. The air supply port has a portion that opens at a position lower than the substrate,
The heat treatment apparatus according to claim 2, wherein the outer peripheral exhaust port includes a portion that opens at a position higher than the substrate. A shutter member that opens and closes a loading / unloading port for loading / unloading a substrate into / from the processing container;
4. The heat treatment apparatus according to claim 2, wherein the airflow curtain is formed closer to the substrate than the shutter member.   At the time when a set time has elapsed from the start of heating of the substrate, or until the set time when the temperature of the substrate exceeds the set temperature, the exhaust gas is exhausted from at least the outer peripheral exhaust port. The heat treatment apparatus according to any one of claims 1 to 4, wherein the heat treatment apparatus is configured to be exhausted from a central exhaust port.   6. The heat treatment apparatus according to claim 5, wherein exhaust is performed at the same time from the outer peripheral exhaust port and the central exhaust port at least from the start of heating the substrate to the set time point.   The heat treatment apparatus according to claim 5 or 6, wherein exhaust is performed at the same time from the outer peripheral exhaust port and the central exhaust port at least after the set time point.   8. The apparatus according to claim 5, wherein the exhaust amount of the central exhaust port is larger than the exhaust amount of the outer peripheral exhaust port at least after the setting time point. The heat treatment apparatus as described.   9. At least one of the exhaust from the outer peripheral exhaust port and the exhaust from the central exhaust port is configured such that the exhaust amount increases or decreases with the passage of time. The heat processing apparatus as described in. The coating film contains a crosslinking agent,
The heat treatment apparatus according to any one of claims 5 to 9, wherein the set time is a time when a crosslinking reaction by the crosslinking agent is completed. An ejector connected to the central exhaust port via an exhaust path so that an exhaust flow is sucked by a flow of suction gas;
The heat treatment apparatus according to claim 1, further comprising: a supply / stop mechanism for supplying and stopping suction gas to the ejector.   The heat treatment apparatus according to claim 11, further comprising a mechanism for heating the suction gas. The discharge side of the ejector is connected to a downstream exhaust passage where exhaust is performed by exhaust force,
The exhaust side is connected to the downstream side exhaust passage, and a dummy ejector for sucking the atmosphere outside the exhaust flow passage by the flow of the suction gas is provided,
The heat treatment according to claim 11 or 12, wherein when the supply of the gas for suction is stopped by the supply / stop mechanism, the gas for suction flows through the dummy ejector. apparatus.   Exhaust between the central exhaust port and the ejector that sucks the exhaust flow in order to suppress exhaust from the central exhaust port when the supply of the suction gas is stopped to stop the suction of the exhaust flow The heat treatment apparatus according to claim 13, wherein a pressure loss portion is provided in the path. In the method of heat-treating the coating film formed on the substrate,
A step of placing and heating the substrate on a placement portion provided in a processing container;
At least when the set time elapses from the start of heating the substrate, or until the set time when the substrate temperature exceeds the set temperature, at least outside the substrate on the mounting portion in plan view. From the outer peripheral exhaust port provided along the circumferential direction and from the air supply port provided along the circumferential direction outside the substrate on the mounting portion as viewed in a plan view while exhausting the inside of the processing container. Taking gas into the processing vessel;
After the setting time point, at least the inside of the processing container is evacuated from the central exhaust port provided on the upper side of the central portion of the substrate on the placement unit, and the gas is supplied from the supply port into the processing container. A heat treatment method comprising the steps of:   The heat treatment method according to claim 15, wherein an airflow curtain directed from one of a position higher than the substrate and a position lower than the substrate to the other is surrounded by the exhaust from the outer peripheral exhaust port.   17. The heat treatment method according to claim 15, wherein exhaust is performed simultaneously through the outer peripheral exhaust port and the central exhaust port at least from the start of heating the substrate to the set time point.   18. The heat treatment method according to claim 15, wherein exhaust is performed simultaneously through the outer peripheral exhaust port and the central exhaust port at least after the set time point. A storage medium storing a computer program used in an apparatus for placing a substrate on which a coating film is formed on a mounting portion in a processing container and heating the coating film,
A storage medium, wherein the computer program includes a group of steps so as to execute the heat treatment method according to any one of claims 15 to 18.