TW201643961A - Heat treatment apparatus, heat treatment method, and storage medium - Google Patents

Abstract

The present invention provides a technique for obtaining good in-plane uniformity with respect to the film thickness of a coating film while preventing a sublimate from leaking out of a processing container in performing a heat treatment on the coating film formed on a wafer. When a crosslinking reaction is performed by placing the wafer (W) coated with the SOC film in a processing container (1) and heating the wafer (W), the crosslinking reaction is performed while exhausting from a central exhaust port (34) in a small exhaust amount and exhausting from an outer circumferential exhaust port (31) in a large exhaust amount. In another embodiment, exhaust only from the outer circumferential exhaust port (31) is performed from the heating start of the wafer (W) and exhaust from the central exhaust port (34) is performed in addition to the exhaust from the outer circumferential exhaust port (31) after the lapse of 20 seconds from the heating start of the wafer (W). In still another embodiment, exhaust is performed only from the outer circumferential exhaust port (31) for 20 seconds from the heating start of the wafer (W) and then exhaust from the central exhaust port (34) is started at the same time that the exhaust from the outer circumferential exhaust port (31) is stopped.

Description

Heat treatment device, heat treatment method and memory medium

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

In the semiconductor manufacturing process, the photoresist pattern is easily collapsed due to the miniaturization of the circuit pattern, and various countermeasures are studied. As one of the measures, a photoresist pattern is formed on a lower layer film formed on a semiconductor wafer "hereinafter referred to as (wafer)", and a pattern of the underlying film is used as an etching mask to perform crystal growth. Round etching. As such a lower layer film, those having high plasma resistance and high etching resistance are sought, and for example, a carbon film [SOC (Spin on Carbon) film] formed by spin coating is used.

The wafer coated with the SOC film is subjected to drying of a solvent which is heated after the coating treatment and remains in the coating film, or a crosslinking reaction of the crosslinking agent, but at this time, a coating film is produced. Sublimation. As a heat treatment device that performs the heat treatment as described above, for example, as disclosed in Patent Document 1, a device is known in which a ring gate is used to block the periphery of a heating plate that heats a substrate, and the periphery of the ring gate is Inert gas intake The heat treatment is performed while exhausting from the upper side of the center portion of the wafer to the inside of the processing space.

In recent years, in order to improve the plasma resistance of the SOC film, it is required to increase the carbon content, and as this method, heating is performed at a temperature higher than the conventional temperature (300 ° C) (350 to 400 ° C). However, when the heating temperature is raised, the low molecular weight polymer or the like is scattered in addition to the sublimated material sublimated from the crosslinking agent contained in the SOC film, and therefore the amount of the sublimate is increased. Therefore, in order to prevent the sublimate from leaking from the inside of the processing container to the outside, it is required to increase the amount of exhaust gas. However, in this case, it is necessary to worry that the airflow hitting the center portion of the wafer surface is increased, and the coating film is raised and the film is raised. Thick in-plane uniformity deteriorates.

[Previous Technical Literature] [Patent Literature]

[Patent Document 1] Japanese Patent Laid-Open Publication No. 2000-124206

The present invention has been made in view of such circumstances, and it is an object of the invention to provide a film for preventing a sublimate from leaking to the outside of a processing container when a coating film formed on a substrate is heat-treated. A technique that achieves good in-plane uniformity.

The heat treatment apparatus according to the present invention is a heat treatment apparatus that heat-treats a coating film formed on a substrate, and is characterized in that: the mounting portion is provided in the processing container, and the substrate is placed; and the heating portion is used to heat the load. a substrate placed on the mounting portion; the air supply port is disposed in a plan view, and is disposed outside the substrate on the mounting portion along the circumferential direction for supplying air into the processing container; the peripheral exhaust port a planar view, disposed on the outer side of the substrate on the mounting portion along the circumferential direction for exhausting the inside of the processing container, and a central exhaust port disposed on the substrate on the mounting portion The upper side of the central portion is for exhausting the inside of the processing container.

The heat treatment method of the present invention is a method of heat-treating a coating film formed on a substrate, characterized in that the substrate is placed on a mounting portion provided in a processing container and heated; The time from the start of heating of the substrate until the time when the set time elapses or the time when the temperature of the substrate exceeds the set temperature, that is, the set time point, is at least viewed from the plane, and is provided on the substrate on the mounting portion in the circumferential direction. The outer peripheral exhaust port exhausts the inside of the processing container, and the gas is taken into the air supply port which is disposed on the outer side of the substrate on the mounting portion in a circumferential direction as viewed in plan. Processing the inside of the container; after the setting point, the processing container is at least the central exhaust port on the upper side of the central portion of the substrate provided on the mounting portion Exhaust gas is carried out, and the gas is taken into the processing container from the aforementioned gas supply port.

The memory medium of the present invention stores a memory medium for a computer program used in a device (the device is a mounting portion in which a substrate on which a coating film is formed is placed in a processing container and heat-treating the coating film) , its characteristics, The aforementioned computer program is programmed into a step group to perform the above-described heat treatment method.

In the present invention, when the substrate is placed on the mounting portion in the processing container, and the coating film formed on the substrate is heat-treated by the heating portion, the outer peripheral exhaust port is used to be placed in the circumferential direction. The substrate on the mounting portion is further outside; and the central exhaust port is disposed above the central portion of the substrate on the mounting portion for exhausting the inside of the processing container. Therefore, during the period in which the fluidity of the coating film is large, at least the exhaust gas due to the peripheral exhaust port can be relied upon, and during the period in which the production of the sublimate is increased, at least the central exhaust port can be used. Exhaust gas, therefore, even if the amount of exhaust gas is small, the sublimate can be prevented from leaking out of the processing container, and good in-plane uniformity can be obtained for the film thickness.

1‧‧‧Processing container

2‧‧‧Bottom structure

3‧‧‧ top board

4‧‧‧vacuum pump

5‧‧‧ ring gate

6‧‧‧Control Department

21‧‧‧heating plate

30‧‧‧Exhaust room

31‧‧‧External exhaust

34‧‧‧Central exhaust

W‧‧‧ wafer

Fig. 1 is a longitudinal sectional view showing a heat treatment apparatus according to an embodiment of the present invention; Side view.

Fig. 2 is a longitudinal sectional side view showing a switch of a ring gate.

Fig. 3 is an explanatory view showing the action of the heat treatment apparatus according to the embodiment of the present invention.

Fig. 4 is a timing chart showing changes in the temperature of the exhaust gas sequence of the heat treatment apparatus and the wafer.

Fig. 5 is an explanatory view showing the action of the heat treatment apparatus according to the embodiment of the present invention.

Fig. 6 is a timing chart showing changes in the temperature of the exhaust gas sequence of the heat treatment apparatus and the wafer.

Fig. 7 is an explanatory view showing the operation of a heat treatment apparatus according to another example of the embodiment of the present invention.

Fig. 8 is a timing chart showing changes in the temperature of the exhaust gas sequence of the heat treatment apparatus and the wafer.

Fig. 9 is an explanatory view showing a heat treatment apparatus according to another example of the embodiment of the present invention.

Fig. 10 is a plan view showing another example of the central exhaust port.

Fig. 11 is a longitudinal sectional side view showing a heat treatment apparatus provided in a heating unit of another example.

Fig. 12 is a longitudinal sectional side view showing a heat treatment apparatus including a mechanism for switching the opening and closing of the exhaust gas.

Fig. 13 is a plan view showing a mechanism for switching the opening and closing of the exhaust gas.

Fig. 14 is a plan view showing another example of a mechanism for switching the opening and closing of the exhaust gas.

Fig. 15 is an explanatory view showing an operation of another example of a mechanism for switching the opening and closing of the exhaust gas.

Fig. 16 is an explanatory view showing an operation of another example of a mechanism for switching the opening and closing of the exhaust gas.

Fig. 17 is a plan view showing another example of a mechanism for switching the opening and closing of the exhaust gas.

Fig. 18 is a plan view showing another example of a mechanism for switching the opening and closing of the exhaust gas.

Fig. 19 is a characteristic diagram showing temporal changes in the number of particles observed in the reference example.

Fig. 20 is a characteristic diagram showing a film thickness distribution of a wafer formed in the examples.

Fig. 21 is a characteristic diagram showing the film thickness distribution of the wafers formed in Examples 3-1 and 3-2.

Fig. 22 is a characteristic diagram showing the film thickness distribution of the wafer formed in Example 3-1.

Fig. 23 is a characteristic diagram showing the film thickness distribution of the wafer formed in Example 3-2.

Fig. 24 is a characteristic diagram showing the film thickness distribution of the wafer formed in Example 3-3.

Fig. 25 is a characteristic diagram showing the film thickness distribution of the wafer formed in Example 3-4.

As shown in Fig. 1, the heat treatment apparatus according to the embodiment of the present invention includes a processing container 1 including a bottom structure 2 constituting a bottom portion, a top plate portion 3 formed as a ceiling surface, and a side surface. Ring gate 5. The processing container 1 is placed in a casing which is an exterior body of a module which forms a positive pressure N ₂ (nitrogen) gas atmosphere, although not shown.

The bottom structure 2 is supported by a base 27 via a support member 26, and the base 27 corresponds to a bottom surface portion of a casing (not shown). The bottom structure 2 has a concave portion formed on the center side of the edge portion 22, and includes a support base 20 made of a flat cylindrical body. The concave portion of the support base 20 is fitted and placed to mount the wafer. The mounting portion of W is the mounting table 21. The outer diameter of the support base 20 is set to, for example, 350 mm, and the outer diameter of the mounting table 21 is set to, for example, 320 mm. The mounting table 21 is provided with a heater 25 composed of a resistance heating body that forms a heating portion for heat-treating the wafer W. Therefore, the mounting table 21 can be said to be a heating plate. In the following description, the mounting table 21 is referred to as a heating plate 21. Further, for example, three support pins 23 are provided at equal intervals in the circumferential direction, and the support pins 23 are configured to penetrate the bottom structure 2 and to receive, for example, a diameter of 300 mm between the transfer arms (not shown) and the outside. Wafer W. The support pin 23 is configured to be lifted and lowered by the elevating mechanism 24 provided on the base 27, and protrudes from the surface of the bottom structure 2.

The top plate portion 3 is composed of a disk-shaped member having a diameter larger than that of the bottom structure 2. The top plate portion 3 is provided to be supported by a ceiling of a casing (not shown), and faces the upper surface of the bottom structure 2 via a gap, and the outer edge thereof is located outside the outer edge of the bottom structure 2 in plan view. On the top Inside the portion 3, a flat cylindrical exhaust chamber 30 is formed, and the exhaust chamber 30 is formed such that its outer edge is substantially the same as the outer edge of the bottom structure 2. In the bottom surface of the exhaust chamber 30, for example, about 100 outer peripheral exhaust ports 31 are opened at equal intervals in the circumferential direction along the edge portion. 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 peripheral exhaust pipe") 32 is connected above the exhaust chamber 30, and when the outer peripheral exhaust pipe 32 is on the upstream side of the top plate portion 3 side, the upstream side is connected. A valve V1 and a flow rate adjusting unit 33 are provided and connected to a factory exhaust path provided in the factory.

Further, in the central portion of the lower surface side of the top plate portion 3, the center exhaust port 34 is opened so that the center thereof coincides with the center of the wafer W placed on the bottom structure 2, and the central exhaust port 34 is formed. One end side of the central exhaust pipe 35 provided to penetrate the top plate portion 3 and the exhaust chamber 30 is connected. When the center exhaust pipe 35 is on the upstream side of the top plate portion 3 side, the valve V2 and the flow rate adjusting portion 38 are interposed from the upstream side and connected to the factory exhaust path.

Further, around the bottom structure 2, a ring gate 5 is provided which is a shutter member for blocking the periphery of the gap between the bottom structure 2 and the ceiling portion 3 to form a processing space. The ring gate 5 is provided with an annular portion 50 in which a hollow band-shaped member is formed into an annular shape.

At a position above the outer peripheral surface of the annular portion 50, it is formed at equal intervals across the entire circumference to suck the outside nitrogen gas into the annular portion 50. The suction port 51 of the internal space (air supply chamber) is formed at a position below the inner circumferential surface of the annular portion 50 at equal intervals across the entire circumference to supply the annular portion to the inside of the processing container 1. The gas supply port 52 of the internal nitrogen gas of 50. An annular annular plate 53 is provided on the lower surface of the annular portion 50, and the annular plate 53 and the annular portion 50 are configured to be integrally raised and lowered by the elevating mechanism 54.

As shown in FIG. 2, the ring gate 5 is disposed such that the inner circumferential surface of the annular portion 50 faces the edge portion 22 of the bottom structure 2 via the gap. When the ring gate 5 is raised, the dotted line in FIG. 2 is as shown in FIG. As shown in the figure, the upper surface of the ring gate 5 is in contact with the lower surface of the peripheral edge portion of the top plate portion 3, and the upper surface side of the inner edge portion of the annular portion 53 is in contact with the segment portion of the edge portion 22 of the bottom structure 2. Thereby, a processing space partitioned by the bottom structure 2, the top plate portion 3, the ring gate 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. Further, when the ring gate 5 is lowered, it is configured to descend to the position shown by the solid line in FIG. 2, and the wafer W is carried in and out around the entire circumference of the processing space. Therefore, the gap between the bottom structure 2 and the top plate portion 3 which is opened by lowering the ring gate 5 corresponds to the loading and unloading of the wafer W.

Further, in the top plate portion 3 and the wall of the processing container 1, a heater (not shown) for preventing precipitation of the sublimate in the wall surface and the top plate portion 3 is embedded, for example, heated to 300 °C.

Returning to Fig. 1, the heat treatment apparatus is provided with a control unit 6 composed of a computer. The control unit 6 has a program storage unit. The storage unit stores a program for loading the wafer W due to the lifting and lowering of the support pin 23, raising and lowering the ring gate 5, heating the heater 25, and switching the valves V1 and V2. The command for the flow rate adjustment by the flow rate adjustment units 33, 38. The program is stored by a memory medium such as a floppy disk, a compact disc, a hard disk, an MO (optical disk), and a memory card, and is installed in the control unit 6.

Next, the action of the heat treatment apparatus according to the embodiment of the present invention will be described. In the front stage processing of the heat treatment apparatus, for example, a coating liquid containing a carbon film precursor is applied to the wafer W to form a coating film, that is, an SOC film. When the wafer W is moved to the upper side of the heating plate 21 by the transfer arm (not shown) in a state where the ring gate 5 is lowered, the cooperation between the transfer arm and the support pin 23 below the heating plate 21 is achieved. Acting to pass the wafer W to the support pin 23. At this time, the electric power of the heater 25 is controlled such that the temperature of the surface of the hot plate 21 becomes, for example, 350 °C. Further, the ring gate 5 is raised to bring the processing container 1 into a closed state, whereby the processing space is formed by the partition. Next, the valves V1 and V2 are opened, and the exhaust gas (flow rate) of, for example, 25 L (liter)/minute is exhausted from the outer peripheral exhaust port 31, and discharged from the central exhaust port 34 at a discharge amount of 5 L/min. The gas causes the inside of the processing container 1 to be in a negative pressure state. Further, for example, the support pin 23 is lowered substantially simultaneously with the exhaust gas in the processing container 1, and the wafer W is placed on the heating plate 21 of the bottom structure 2.

As shown in FIG. 3, the outside atmosphere of the processing container 1, that is, nitrogen gas, which is an inert gas atmosphere in a casing (not shown), flows into the annular portion 50 from the suction port 51 provided in the ring gate 5, and further passes through the air supply port 52. Flow into Processing inside the container 1. Since the air supply port 52 of the ring gate 5 is disposed at a position lower than the height of the upper surface of the bottom structure 2, the nitrogen gas taken into the processing space is on the side of the bottom structure 2 and the ring gate 5 The gap flows upwards. Further, in FIGS. 3, 5, and 7, the wafer W having a low surface fluidity due to the crosslinking reaction is attached with hatching.

The airflow that has risen to the upper outer edge of the bottom structure 2 is formed by flowing air directly to the upper portion and exhausted to the outer peripheral exhaust port 31; and toward the bottom structure 2 along the upper surface of the bottom structure 2 In the center portion, the airflow that is exhausted toward the center exhaust port 34 is formed, and an air curtain is formed around the processing space.

4 is a view showing the manner in which the respective exhaust amounts of the (1) outer peripheral exhaust port 31 and the (2) central exhaust port 34 correspond to the temperature of the wafer W after the wafer W is placed on the heating plate 21. To represent the chart. The wafer W is heated from the heating start time t0 after being placed on the hot plate 21, thereby promoting evaporation of the solvent in the coating film (SOC film) and crosslinking by coating the film. The crosslinking reaction proceeds. For example, the coating film is in a state in which the crosslinking reaction proceeds and the fluidity is high, for about 20 seconds from the time t0. During this period, although the crosslinking agent or the low molecular component in the coating film is volatilized, as shown in FIG. 3, the exhaust gas flow toward the outer peripheral exhaust port 31 side and the orientation are formed in the processing container 1. The exhaust flow on the side of the central exhaust port 34, therefore, the volatile components are exhausted along with the exhaust flow.

Further, by using the outer peripheral exhaust port 31, since the air curtain is formed around the processing atmosphere and the leakage preventing function of the volatile component acts outside, the exhaust toward the central exhaust port 34 can be reduced. The amount is therefore set to a small flow rate of, for example, 5 L/min. When the flow rate of the exhaust gas at the central exhaust port 34 is large and the flow of air flowing from the outer side of the wafer W to the central exhaust port 34 is too strong, the surface of the wafer W where the center of the wafer W is raised due to the air flow may occur. Strip unevenness is formed, and the in-plane uniformity of the film thickness is deteriorated. On the other hand, if the flow rate of the exhaust gas of the central exhaust port 34 is a small flow rate of 5 L/min, formation of a film bulge or strip unevenness can be suppressed.

When the crosslinking time of the coating film is completed at time t1 (the time point of 20 seconds from t0), the wafer W is further heated to reach the surface temperature of the hot plate 21, for example, 350 °C. Thereafter, the wafer W is maintained at this temperature, and the remaining diluent or other components are volatilized or sublimated, and the coating film is modified, and the time is elapsed, for example, 80 seconds after the heating start time t0 of the wafer W. In t2, the wafer W is lifted from the heating plate 21 by the support pin 23. After the completion of the crosslinking reaction, the amount of the sublimate is increased. However, since the exhaust gas is discharged from the central exhaust port 34 at a flow rate of 5 L/min, the sublimate is mainly directed from the outer periphery of the bottom structure 2 toward the center. The exhaust flow of the exhaust port 34 is exhausted. Therefore, even if the amount of exhaust gas from the outer peripheral exhaust port 31 is a flow rate as small as 25 L/min, that is, even if the flow of the air curtain surrounding the processing space is weak, the sublimate does not leak to the outside of the processing container 1.

After the end of the cross-linking reaction, if the exhaust of the central exhaust port 34 is not exhausted and the exhaust of only the outer peripheral exhaust port 31 is to be used, it is understood from the data to be described later that the amount of exhaust gas must be significantly increased. This results in an excess of the amount of exhaust gas distributed in the plant in the work area where the system incorporating the heat treatment device is disposed.

Fig. 5 shows that at time t2, the wafer W is lifted away from the heating plate 21, or at the same time, the ring gate 5 is in an open state. By opening the ring gate 5 and the gap is open, although the atmosphere in the processing container 1 flows from the gap to the outside, since the exhaust gas continues from the outer exhaust port 31 and the central exhaust port 34, the external nitrogen gas is Inhaled into the processing space. Therefore, even when the sublimate generated during the heating process of the wafer W cannot be completely exhausted, the sublimate can be prevented from leaking to the outside of the processing container 1.

According to the above-described embodiment, when the wafer W coated with the SOC film as a coating film is placed in the processing container 1 and the wafer W is heated to perform the crosslinking reaction, the central exhaust port 34 is less. The exhaust gas amount is exhausted, and the cross-linking reaction is performed while exhausting from the outer peripheral exhaust port 31 with a large exhaust gas amount. Therefore, when the fluidity of the SOC film is large, the center of the surface of the wafer W is not exposed to a strong gas flow, and the bulging of the central portion can be suppressed, and the deterioration of the uniformity of the film thickness can be avoided. Since the exhaust of the central exhaust port 34 is also performed after the completion of the cross-linking reaction, the exhaust of the central exhaust port 34 is performed. Therefore, even if the exhaust amount of the outer peripheral exhaust port 31 is small, the ring gate can be opened during processing or open. After 5, the sublimate is prevented from leaking to the outside of the atmosphere in the processing container 1. In view of the prevention of environmental pollution and the like, the demand for suppressing the amount of exhaust gas in the plant is increased, and in the above-described embodiment, it is effective in suppressing the amount of exhaust of the entire heat treatment device. technology.

Other embodiments of the present invention will be described. For example, only the exhaust of the peripheral exhaust port 31 is performed from the heating of the wafer W and from the crystal After the heating of the circle W has elapsed after the set time has elapsed, that is, after the completion of the crosslinking reaction, the exhaust gas from the outer peripheral exhaust port 31 may be exhausted from the central exhaust port 34. Fig. 6 is a timing chart showing another embodiment of the present invention as described above, wherein (1) shows the amount of exhaust of the outer peripheral exhaust port 31, and (2) shows the amount of exhaust of the central exhaust port 34. .

In this embodiment, after the wafer W is supported by the support pin 23, the valve V1 is opened, the exhaust gas is exhausted from the outer peripheral exhaust port 31 at a flow rate of 10 L/min, and the ring gate 5 is closed thereafter or simultaneously. Next, at time t0, the wafer W is placed on the bottom structure 2 and heating is started. Thereafter, the time t0 from the start of heating of the wafer W is, for example, 20 seconds, the crosslinking reaction is completed, and at the time t1 when the fluidity of the SOC film becomes small, the valve V2 is opened, except for the exhaust of the outer peripheral exhaust port 31. Exhaust from the central exhaust port 34 to achieve a displacement of 20 L/min. The exhaust gas of the central exhaust port 34 is gradually increased by the flow rate adjusting unit 38 from the time t1, for example, at a time point of 10 seconds after the elapse of 10 seconds from the time t1, to reach 20 L/min. The way of the displacement is programmed into a sequence.

In the above-described embodiment, the period from the time t0 to the time t1 during which the cross-linking reaction of the SOC film proceeds is based on the exhaust of the outer peripheral exhaust port 31 without exhausting the central exhaust port 34. The central portion of the surface of the circle W is not exposed to a strong air flow from the outer circumference toward the center, and the formation of the bulge of the central portion of the wafer W can be suppressed. Further, since the amount of volatile matter and sublimate from the SOC film is small in this time interval, even if only the exhaust of the outer peripheral exhaust port 31 is exhausted, the particles can be prevented from leaking out of the processing container 1. Moreover, due to the cross-linking of the SOC film After the time t1 after the completion, the fluidity of the center surface of the wafer W is lowered. Therefore, even if the surface of the wafer W is exposed to a strong gas flow, the surface of the film is hard to rise.

Therefore, as shown in FIG. 7, in addition to the exhaust gas from the outer peripheral exhaust port 31, the exhaust gas can be exhausted from the central exhaust port 34 with a large exhaust amount, and the sublimate generated from the SOC film is increased. Under the condition, the sublimate can be removed efficiently. Further, after the completion of the heat treatment of the wafer W, when the ring gate 5 is opened, since the airflow flowing from the gap to the outer peripheral exhaust port 31 is formed in the same manner as in FIG. 5, the atmosphere in the processing container 1 can be prevented. Leak to the outside. In this way, since the exhaust gas is exhausted from the central exhaust port with a large exhaust gas amount, the amount of exhaust gas from the outer peripheral exhaust port 31 can be reduced, and as a result, the total exhaust gas amount can be reduced. .

Further, for example, when the wafer W is heated, the exhaust gas from the outer peripheral exhaust port 31 may be switched to the exhaust gas from the central exhaust port 34. Fig. 8 is a timing chart showing another embodiment of the present invention as described above, wherein (1) shows the amount of exhaust of the outer peripheral exhaust port 31, and (2) shows the row of the central exhaust port 34. Gas volume. In this embodiment, after the wafer W is supported by the support pin 23, first, the exhaust gas is exhausted from the outer peripheral exhaust port 31 at an exhaust amount of 10 L/min, and the ring gate 5 is closed thereafter or simultaneously. Next, at time t0, the wafer W is placed on the bottom structure 2 and heating is started. Thereafter, from the time t0 to the time t1 from the start of heating of the wafer W, only the outer peripheral exhaust port 31 is exhausted, and thereafter, the time from the start of heating of the wafer W is 20 seconds, and the crosslinking reaction is performed. End, in the SOC film At the time t1 when the fluidity is small, the amount of exhaust of the outer peripheral exhaust port 31 is gradually reduced. For example, after 10 seconds elapse from the time t1, the exhaust gas is stopped. On the other hand, from time t1, the amount of exhaust of the central exhaust port 34 is gradually increased. For example, after 10 seconds elapse from time t1, the exhaust gas is exhausted at a displacement of 30 L/min.

In the above-described embodiment, the center portion of the surface of the wafer W is not exposed to a strong gas flow from the outer periphery toward the center during the period from the time t0 to the time t1 during which the crosslinking reaction of the SOC film proceeds, and the suppression can be suppressed. The formation of the ridge of the central portion of the wafer W. Further, since the amount of volatile matter and sublimate from the SOC film is small in this time interval, even if only the exhaust of the outer peripheral exhaust port 31 is exhausted, the particles can be prevented from leaking out of the processing container 1. Further, after time t1 after completion of the crosslinking reaction of the SOC film, even if the surface of the wafer W is exposed to a strong gas flow, the surface of the film is hard to rise. Therefore, the exhaust gas can be exhausted from the central exhaust port 34 with a large exhaust gas amount, and the sublimate can be efficiently removed even in the case where the sublimate generated from the SOC film is increased. Further, after the completion of the heat treatment of the wafer W, when the ring gate 5 is opened, the sublimate can be sufficiently exhausted by the exhaust gas from the central exhaust port 34 in advance, thereby preventing the sublimate from leaking to The outside of the container 1 is processed.

Here, when the sequence shown in FIGS. 6 and 8 is executed, the timing at which the exhaust of the central exhaust port 34 starts may be the elapsed time from the start of heating of the wafer W, that is, the time t0. Management is performed, but it is also possible to detect that the temperature of the wafer W is set to a predetermined temperature. That is, at the time point after the set time elapses from the start of heating of the wafer W or When the temperature of the wafer W exceeds the set temperature, that is, the set time point, for example, the start point of the exhaust of the central exhaust port 34 can be set. Further, the detection of the temperature of the wafer W can be performed, for example, by providing a temperature detecting portion such as a thermocouple on the heating plate 21.

In addition, the point of the setting is the time when the crosslinking reaction of the coating film is completed, but the "time when the crosslinking reaction ends" as claimed in the patent application is judged to be common sense even if observed by anyone. The time at which the fluidity of the coating film is not present, and also includes, for example, 2 seconds before, for example, 1 second after the end of the crosslinking reaction or after the end of the crosslinking reaction. Further, for example, in the fifth embodiment to be described later, the exhaust gas amount of the central exhaust port 34 is set to 25 L/min for 20 seconds after the start of heating, but the exhaust gas is 20 after the start of the heating. When the exhaust is started earlier than the second, the film thickness at the center of the wafer W is raised. Therefore, when the central exhaust port 34 is exhausted at a displacement of 25 L/min after a certain sequence, the timing at which the film thickness at the center of the wafer W is significantly raised is also referred to as "crosslinking". The point at which the reaction ends."

Further, after 20 seconds from the heating of the wafer W and the crosslinking reaction is completed, it is preferable to evacuate the sublimate efficiently. Therefore, it is preferable to make the amount of exhaust of the central exhaust port 34 larger than the amount of exhaust of the outer exhaust port 31. However, it is appropriate to increase the amount of exhaust gas of the amount of exhaust gas of the central exhaust port 34 and the amount of exhaust of the outer peripheral exhaust port 31, depending on the type, viscosity, and film thickness of the coating film. The difference is changed depending on the shape of the processing container 1.

Moreover, during the heat treatment of the wafer W, the central exhaust port 34 or the outside The amount of exhaust gas of the peripheral exhaust port 31 is not limited to a certain value, and the amount of exhaust gas may be changed by the elapsed time from the start of heating. For example, the amount of exhaust of the outer peripheral exhaust port 31 may be set to 25 L/min, and the amount of exhaust of the central exhaust port 34 may be set to 5 L/min, starting from the heating of the wafer W. After 20 seconds elapsed, the amount of exhaust of the outer exhaust port 31 was changed to 10 L/min, and the amount of exhaust of the center exhaust port 34 was changed to 20 L/min. Moreover, it is also possible to gradually increase or decrease the amount of exhaust gas as time passes. Further, after the amount of exhaust of the central exhaust port 34 and the outer peripheral exhaust port 31 is temporarily increased, the amount of exhaust is decreased. Or, after a temporary decrease, the second increase also includes "increasing or decreasing the amount of exhaust gas over time".

Further, in the heat treatment apparatus according to the present invention, as shown in Fig. 9, in the processing container 1, the air supply port 72 of the external atmosphere is disposed at a position higher than the wafer W, and the outer circumference exhaust port 71 is disposed below. The location of the wafer W. For example, a plurality of air supply ports 72 may be provided in the circumferential direction at a position above the ring gate 75, and a plurality of outer circumferential exhaust ports 71 may be provided in the circumferential direction on the base 27 supporting the bottom structure 2. Further, in FIG. 9, the air supply port 72 may be opened at a position below the top plate portion 3 and opposed to the outer circumferential exhaust port 71 instead of being provided on the upper side of the ring gate 75. In this case, the air supply path is formed in the top plate portion 3, for example, on the base end side, and is open to the side surface of the top plate portion 3. As long as the configuration is such that the outside of the bottom structure 2 is formed, a curtain that flows downward from the top plate portion 3 is formed. Further, the present invention is not limited to the heat treatment apparatus for heating the SOC film, and may be, for example, a heat treatment apparatus that performs heat treatment after applying the coating liquid for the anti-reflection film.

Further, the central exhaust port 34 is not limited to a configuration in which one central exhaust port 34 is provided at the center portion of the lower surface side of the top plate portion 3 in the processing container 1. For example, as shown in FIG. 10(a), a plurality of, for example, eight circular exhaust ports may be provided at equal intervals in the circumferential direction on a circumference of a circle centered on the center portion of the wafer W. 81 comes as a central exhaust port 34. Further, as shown in FIG. 10(b), a slit-shaped opening portion 82 that forms a central exhaust port 34 may be provided at four locations that are 90 degrees apart from each other around the center portion of the wafer W. . Alternatively, as shown in FIG. 10(c), for example, eight rectangular openings 83 may be arranged in a square centered on the center portion of the wafer W as the central exhaust port 34, or as shown in FIG. (d), four opening portions 84 having a triangular shape may be arranged at equal intervals in the circumferential direction around the center portion of the wafer W as the central exhaust port 34. Further, as shown in FIG. 10(e), the concentric circular double-shaped slits 85a and 85b centering on the center portion of the wafer W may be used (in detail, due to the slits 85a and 85b). In the middle of the middle, there is a bridge portion, so that it has an arc shape, and constitutes a central exhaust port 34. In this manner, the central exhaust port 34 is symmetrically arranged in the circumferential direction with respect to the upper side of the center of the wafer W, and the external atmosphere supplied to the processing container 1 can be formed from the periphery of the wafer W. The direction has a high uniformity and faces the airflow above the center of the wafer W. Therefore, since the sublimate can be efficiently recovered, the same effect can be obtained.

Further, when the installation position of the outer peripheral exhaust port 31 is formed at a position close to the center of the top plate portion 3 of the processing container 1, the sublimate recovery efficiency is improved, but the film thickness uniformity tends to be deteriorated. The other side When the position where the outer peripheral exhaust port 31 is disposed is located away from the center of the top plate portion 3 of the processing container 1, the film thickness uniformity is improved, but the sublimate recovery efficiency is lowered. Further, when the opening diameter of the outer peripheral exhaust port 31 becomes small, the flow velocity is increased and the sublimate recovery efficiency is increased. Therefore, the position of the outer peripheral exhaust port 31 is preferably disposed on a circumference having 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, and the opening diameter of the outer peripheral exhaust port 31 is 1 ~3 mm, for example 2 mm is preferred.

Further, the heating portion for heating the wafer W may be, for example, a heat radiation source that heats the wafer W by irradiating light from a light source such as an LED. As such an example, a configuration is as follows. For example, as shown in FIG. 11, an LED array 91 forming a heat radiation source is provided on the bottom surface of the concave portion of the support table 20 instead of the heating plate 21 of the bottom structure 2. . The LED array 91 is configured to be surrounded by the entire circumference of the LED array 91, for example, by a reflection plate 93 plated with copper (Cu) gold, and is reflected in a direction different from the irradiation direction (in the direction of the upper direction in FIG. 11). The light is effectively taken out of the radiant light.

Further, a transmissive plate 92 is provided on the upper side of the LED array 91, and the transmissive plate 92 is made of, for example, quartz for separating the atmosphere in which the LED array 91 is provided and the processing atmosphere. Further, inside the transmission plate 92, a cooling line 94, which is a flow passage through which a refrigerant, for example, cooling water, is passed, and a transmission plate 92 serves as a cooling member for cooling the wafer W after the heat treatment. The cooling line 94 is connected to the cooler 95 and the circulation pump 96 provided outside the processing container 1, and the refrigerant circulating in the cooling line is adjusted to the set temperature by the cooler 95. It is sent to the permeation plate 92 by the circulation pump 96.

In this example, after the wafer W is transferred to the support pin 23, the wafer W is lowered, and the wafer W is moved to a height (heating height position) at which the heat treatment is performed. When the wafer W is held at the heating height position, the LED W is irradiated toward the wafer W toward the absorption wavelength of the wafer W, that is, the infrared light, so that the wafer W is heated to a predetermined heat treatment. temperature. Therefore, in this example, the support pin 23 corresponds to the placing 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 the upper side to heat the wafer W.

Next, another embodiment of the present invention will be described. In this embodiment, an ejector is used as an example of a mechanism for switching the opening and closing of the exhaust of the central exhaust pipe 35. As shown in FIG. 12, the central exhaust pipe 35 extends from the central exhaust port 34 via the buffer chamber 34a along the upper surface of the top plate portion 3, and is connected to the suction port of the injector 101. The upper surface side of the top plate portion 3 is covered by the covering body 300, and is formed as a partition space 301 which is partitioned from the outside, and the ejector 101 and its peripheral portion are disposed in the partition space 301. In the top plate portion 3, a heater 302 is provided, and the temperature of the sublimate contained in the exhaust gas flow in the outer peripheral exhaust pipe 32 and the central exhaust pipe 35 is prevented by the heater 302, for example, 300. °C is used to heat the compartment 301.

Fig. 13 is a plan view showing the upper surface side of the top plate portion 3, and 321 is an outer peripheral exhaust path formed by a duct. The duct 321 is formed by The opening portion of the top plate portion 3 communicates with the exhaust chamber 30, and the upstream side surrounds the buffer chamber 35, and is disposed in a linear shape in the partition space 301 as shown in FIG.

Referring to Figure 13, the injector 101 and its peripheral portions will be described. When the downstream side of the outer peripheral exhaust path 321 is set to the front side and the upstream side is set to the rear side, the air supply pipe 102 extends from the front side toward the rear side with respect to the center exhaust port 34 on the right side in FIG. The air supply pipe 102 is a supply pipe for air which is a suction gas of the ejector 101. The valve 99 in the figure constitutes a supply/stop mechanism for air. The air supply pipe 102 is formed as a curved passage on the rear side of the central exhaust port 34 to constitute a heat exchange portion 103. The heat exchange unit 103 is made of, for example, a metal material having good thermal conductivity, and a heating flow path 104 is formed inside. The heating flow path 104 is viewed from the front side to the heat exchange unit 103, and extends from the right rear position to the rear side, and is bent right and left several times to open to the left side of the front surface of the heat exchange unit 103, and to the left of the heating flow path 104. The end of the exhaust pipe 106 is connected to the end. The air supplied to the heating flow path 104 is room temperature, and the temperature of the heater 302 is raised to a temperature at which the adhesion of the sublimate is prevented. Therefore, the heater 302 and the heat exchange unit 103 constitute a temperature adjustment mechanism for the gas.

The ejector 101 is composed of a T-shaped piping structure, and the T-shaped piping structure is connected to the gas line 101A extending in a straight line from the side. The downstream end of the air supply pipe 102 is connected to one end side of the gas pipe 101A, and the other end side (discharge side) of the gas pipe 101A is via the exhaust pipe 106 and the intermediate pipe. 105, connected to the exhaust duct 100 that is led to the downstream side exhaust path in the factory. The exhaust duct 100 is constantly exhausted by exhaust power, that is, factory power. Further, in the joining line 101B forming the suction port of the ejector 101, the downstream end of the center exhaust pipe 35 is connected. 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 action of the above embodiment will be described with reference to the timing chart shown in FIG. 6. First, after the exhaust of the outer peripheral exhaust port 31 is performed from the heating of the wafer W, and the cross-linking reaction is completed after the lapse of the set time from the heating of the wafer W, the example of FIG. 6 is at the end of the cross-linking reaction. At the time t1 when the fluidity of the SOC film is reduced, the exhaust gas from the outer exhaust port 31 is exhausted from the central exhaust port 34. When the exhaust is started 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 injector 101 via the heat exchange unit 103.

When passing through the heat exchange unit 103, the air is heat-exchanged between the atmosphere in the compartment 301 after heating by the heater 302, and is heated for a sufficient time to be exhausted without adhering to the air. The temperature of the sublimate in the stream. The heated air flows as a gas for suction in the gas line 101A of the ejector 101, and a gas which is negatively pressurized in the merging line 101B of the ejector 101 and introduced into the side of the central exhaust pipe 35 is used. This exhausts the atmosphere in the processing container 1 from the central exhaust port 34. Further, the atmosphere sucked into the processing container 1 of the joining line 101B is merged with the heated air flowing through the gas line 101A, and then passed through the exhaust pipe 106 and the intermediate duct 105 to the exhaust duct. 100 exhaust.

As described above, since the air is heated, the temperature of the exhaust gas flowing from the joining line 101B does not decrease, and on the side of the exhaust duct 100, the precipitation of the sublimate contained in the exhaust stream is suppressed.

Thereafter, when the exhaust from the central exhaust port 34 is stopped, the valve 99 is closed to stop the supply of air from the air supply pipe 102. Thereby, since the air does not flow in the gas line 101A, the suction action in the joining line 101B disappears, and the exhaust of the center exhaust pipe 34 is stopped.

According to this embodiment, the effects as described below are obtained. The upper portion of the heat treatment device is heated to a high temperature due to the influence of the heat treatment. Therefore, for example, when the valve device is provided to switch the opening and closing of the exhaust gas at the central exhaust port 34, it is necessary to drive at a high temperature. Valve, but valves like this are large and heavy. On the other hand, if the ejector 101 is provided in the center exhaust pipe 35, it can be a simple and compact device configuration.

Here, although the exhaust gas of the heat treatment apparatus is performed by the factory power, it is in a state of being exhausted frequently by the power of the factory. Therefore, the exhaust duct 100 always becomes a negative pressure, and when the supply of air is stopped and the exhaust is stopped, the central exhaust pipe 35 connected to the injector 101 becomes easy to be formed depending on the amount of exhaust of the factory power. Negative pressure, while slightly exhausting from the central exhaust port 34.

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

Further, in the middle of the dummy pipe 107, the ejector 110 having the same configuration as that of the ejector 101 is provided, and the air flowing through the dummy pipe 107 flows in the gas pipe 110A of the ejector 110, and is configured to be open. The end portion (suction port) of the joining line 110B of the ejector 110 takes in an atmosphere other than the flow path through which the exhaust gas flows, for example, an atmosphere outside the compartment 301.

When the exhaust gas from the central exhaust port 34 is exhausted, the air operation valve 108 is switched to supply the air to the heat exchange unit 103 side, whereby the air is discharged from the central exhaust port 34 as shown in FIG. Exhaust. Thereafter, when the exhaust gas from the central exhaust port 34 is stopped, the air operation valve 108 is switched, the supply of air to the heat exchange unit 103 side is stopped, and the supply of air is started to the virtual pipe 107 side. As a result, as shown in FIG. 16, an external atmosphere is introduced from the joining line 110B of the ejector 110 provided in the dummy pipe 107, and flows into the exhaust duct 100. Therefore, when the exhaust gas from the central exhaust port 34 is stopped, when the exhaust duct 100 is under a negative pressure, the atmosphere from the side of the dummy pipe 107 flows, and the negative pressure in the exhaust duct 100 is suppressed. Therefore, the introduction of the exhaust gas on the side of the exhaust pipe 106 is suppressed.

In this way, as long as the virtual injector 107 is combined with the virtual injector 110 and virtual introduction is performed when the exhaust flow is stopped, the use is performed. In the ejector 101, the exhaust gas flow rate when the exhaust gas flow is exhausted by the exhaust duct 100 coincides with the exhaust gas flow rate at the time of virtual introduction. Therefore, when the exhaust gas flow rate corresponding to the exhaust gas flow is set on the power side of the plant, when the supply of air is switched to the virtual pipe 107 side, the negative in the central exhaust pipe 35 can be suppressed with high certainty. The production of pressure. Therefore, the outflow of the processing atmosphere from the central exhaust port 34 can be suppressed. For example, in such a configuration, when the suction action of the ejector 101 is stopped, it is preferable to suppress the flow rate of the exhaust gas from the central exhaust port 34 to a flow rate of 2 L/min or less.

Further, as shown in FIG. 17, a dummy pipe 107 may be provided, and a pressure loss portion 101C may be provided in a portion of the merging pipe 101B in the ejector 101 connected to the center exhaust pipe 35, so that the center exhaust pipe 35 is provided. The injector 101 on the side has a higher pressure loss than the injector 110 on the side of the dummy pipe 107. The pressure loss portion 101C is configured to, for example, reduce a diameter of a part of the flow path (a portion having a smaller diameter than the front and rear). In this way, when the air operation valve 108 is switched and the suction of the exhaust gas flow on the center exhaust pipe 35 side is stopped, the atmosphere on the side of the dummy pipe 107 is more easily introduced, and therefore, the pressure from the central exhaust port 34 can be suppressed. Handle the outflow of the atmosphere. The pressure loss portion 101C is not limited to the position shown in FIG. 17, and can be obtained by the manner of being disposed in the exhaust path from the central exhaust port 34 to the portion of the injector 101 where the air merges with the air. .

Further, as shown in FIG. 18, a check valve 109 may be provided in the exhaust pipe 106. In this case, as long as the pressure difference between the upstream side and the downstream side of the check valve 109 is not large, the check valve 109 may not be circulated. With such a configuration, the suction of the injector 101 is stopped. At the time of action, since the gas on the side of the injector 101 is blocked by the flow of the check valve, the same effect can be obtained.

[Example 1]

An embodiment performed to examine the effects of the embodiment of the present invention is described. The wafer W coated with the SOC film was heated to 350 ° C by using a heat treatment apparatus as in the embodiment of the present invention. During the heat treatment of the wafer W, the central exhaust port 34 and the outer peripheral exhaust port 31 are exhausted from the processing container 1 until the time of taking out, and the number of fine particles of 100 nm or more is counted outside the processing container 1. The exhaust gas flow rate of the central exhaust port 34 and the exhaust gas volume of the outer peripheral exhaust port 31 in each of the embodiments are set as follows. Further, the wafer W is placed in the processing container 1 and placed on the bottom structure 2, and then heat-treated for 80 seconds. Thereafter, the ring gate 5 is opened and the wafer W is taken out.

(Example 1-1)

The amount of exhaust of the outer peripheral exhaust port 31 is set to 20 L/min, and the amount of exhaust of the central exhaust port 34 is set to 10 L/min, and is carried out from the wafer W into the processing container 1 until the time of taking out. The outer peripheral exhaust port 31 and the central exhaust port 34 are exhausted.

(Example 1-2)

Except that the exhaust amount of the outer 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, the rest is set to Example 1-1 was the same.

(Example 1-3)

Except that the exhaust amount of the peripheral exhaust port 31 was set to 10 L/min, and 20 seconds after the start of heating of the wafer W, exhaust gas was started from the central exhaust port 34 at a displacement of 20 L/min (except for the periphery). Other than the exhaust of the exhaust port 31, the exhaust of the central exhaust port 34 was further set to be the same as that of Example 1-1.

(Examples 1-4)

The same as Example 1-3 except that the exhaust amount of the outer 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)

The same as Example 1-3 except that the exhaust amount of the outer 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, the following example is used as a reference example, except that the exhaust gas is not exhausted from the central exhaust port 34, and only the outer peripheral exhaust port 31 is used for exhausting, and the wafer W is heated, and the first embodiment is the same as the first embodiment. -1 is processed in the same manner. In the reference example, the flow of the exhaust gas of the peripheral exhaust port 31 The amount is 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 the exhaust gas of the outer peripheral exhaust port 31 in the reference example is set to each flow rate. . When the flow rate of the exhaust gas of the outer peripheral exhaust port 31 is 0 L/min, that is, when the exhaust gas is not exhausted, it is known that the atmosphere containing the sublimate is discharged from the suction port before the opening of the ring gate 5. Further, when the flow rate of the exhaust gas is set to a flow rate of 0 to 50 L/min, the particles are observed after the ring gate 5 is opened, and when the flow rate is set to 60 L/min, the ring gate 5 is opened, and No particles were observed. Therefore, when exhausting only from the outer peripheral exhaust port 31, it can be said that the leakage flow rate must be set to 60 L/min or more in order to prevent leakage of the sublimate when the wafer W is taken out.

On the other hand, in Examples 1-1 and 1-2, not only the period of the heat treatment but also the particles were not confirmed after the opening of the ring gate 5. Therefore, it is understood that the exhaust of the sublimate can be suppressed by exhausting both the central exhaust port 34 and the outer peripheral exhaust port 31. Further, in the same manner as in the examples 1-3 to 1-5, not only the particles during the heat treatment but also after the opening of the ring gate 5 were not observed. When the exhaust gas is exhausted 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 it can be said that the leakage of the sublimate when the ring gate 5 is opened can be suppressed.

20 is a characteristic diagram showing the film thickness distribution on the diameter of the wafer W after heat treatment in Examples 1-2 and 1-5, and the horizontal axis indicates the diameter of the wafer W. Distance from the center, vertical axis Indicates the film thickness of the SOC film.

According to this result, the ridge of the film at the center of the wafer W is suppressed, and the difference between the maximum value and the minimum value of the film thickness of the SOC film is 0.73 nm in the embodiment 1-2, and 0.71 in the fifth embodiment. Nm. Therefore, according to the embodiment of the present invention, it can be said that the in-plane uniformity of the wafer W after the heat treatment is ensured is good.

[Embodiment 2]

In the central exhaust mechanism, investigation is made as to whether or not there is a clogging of the sublimate due to the presence or absence of the heat exchange unit 103.

[Example 2-1]

In the heat treatment apparatus shown in Fig. 1, an opening and closing mechanism of the exhaust gas as shown in Figs. 12 and 13 was set to perform the test. 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 gas flow rate of the outer peripheral exhaust port 31 was set to 20 L/min.

[Comparative example]

The test was carried out using the same heat treatment device and the opening and closing mechanism of the exhaust gas as in Example 2, except that the heat exchange unit 103 was not provided and the air was supplied from the air supply pipe 102 to the ejector 101. Heating plate 21 The heating temperature 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 gas 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 the treatment of 2,500 wafers W, the adhesion of the sublimate in the ejector 100 was investigated. In the comparative example, it was confirmed that the sublimate was clogged, and the exhaust gas flow rate also dropped to about 40% of the flow rate before the test. On the other hand, in Example 2-1, no sublimate clogging was observed, and the exhaust gas flow rate was also approximately 100% of the flow rate before the test.

According to this result, it can be said that when the central exhaust mechanism is provided, the air heated by the heat exchange unit 103 is supplied to the ejector 101, whereby the adhesion of the sublimate can be suppressed.

[Example 3]

In order to verify the effect of the heat treatment apparatus provided with the opening and closing mechanism of the exhaust gas, heat treatment was performed in accordance with the following examples, and the uniformity of the film thickness was investigated.

[Example 3-1]

After the coating liquid A is applied onto the wafer W, heat treatment is performed in accordance with the timing chart shown in FIG. 6 using a heat treatment apparatus as shown in FIG. The flow rate of the central exhaust port 34 is set to 20 L/min, and the outer peripheral exhaust port 31 is The exhaust gas flow rate was set to 20 L/min, and after 20 seconds from the start of heating, the exhaust gas was started from the central exhaust port 34.

[Example 3-2]

The treatment was carried out in the same manner as in Example 3-1 except that the opening and closing mechanism of the exhaust gas shown in Figs. 12 and 13 was connected to the heat treatment apparatus shown in Fig. 1 .

[Example 3-3]

The coating liquid B was applied to the wafer W, and after the lapse of 15 seconds from the start of heating, the gas was discharged from the central exhaust port 34, and the same treatment as in Example 3-1 was carried out.

[Example 3-4]

The treatment was carried out in the same manner as in Example 3-3, except that the opening and closing mechanism of the exhaust gas shown in Figs. 12 and 13 was connected to the heat treatment apparatus shown in Fig. 1 .

[test results]

Fig. 21 is a characteristic diagram showing the film thickness distribution on the diameter of the wafer W after heat treatment in the embodiment 3-1 and the embodiment 3-2, and the horizontal axis indicates the center portion of the diameter of the wafer W. The distance of the vertical axis represents the film thickness of the SOC film. 22 to 25, the film thickness distribution of the wafer W after heat treatment in each of Examples 3-1 to 3-4 is shown by a contour line. Sexual map.

In Fig. 21, the difference between the maximum value and the minimum value of the film thickness of the wafer W is 1.03 nm in the embodiment 3-1 and 0.52 nm in the embodiment 3-2. Further, in FIGS. 22 to 25, the values of the film thickness at the 80 points on the wafer were 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. Further, for Examples 3-3 and 3-4, 3σ 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, and in Example 3-2, the difference between the maximum value and the minimum value of the film thickness and 3σ The lines are 0.77 nm and 1.23 nm, respectively. Further, in Example 3-3, 3σ was 3.03 nm, and in Example 3-4, 3σ was 2.01 nm. Therefore, in Example 3-2, the difference between the maximum value and the minimum value of the film thickness and the 3σ are smaller than those of the embodiment 3-1, and the uniformity of the film thickness is good, and the embodiment 3-4 is smaller than the embodiment 3-3. The uniformity of the film thickness is good.

According to the result, it can be said that the uniformity of the film thickness is further improved by switching the opening and closing of the central exhaust gas by using the opening and closing mechanism of the exhaust gas.

1‧‧‧Processing container

2‧‧‧Bottom structure

3‧‧‧ top board

5‧‧‧ ring gate

21‧‧‧heating plate

23‧‧‧Support pins

24‧‧‧ Lifting mechanism

27‧‧‧Abutment

30‧‧‧Exhaust room

31‧‧‧External exhaust

32‧‧‧External exhaust pipe

34‧‧‧Central exhaust

35‧‧‧ buffer room

51‧‧‧Inhalation

52‧‧‧ gas supply port

V1‧‧‧ valve

V2‧‧‧ valve

W‧‧‧ wafer

Claims (19)

A heat treatment apparatus for heat-treating a coating film formed on a coating film of a substrate, comprising: a mounting portion provided in the processing container to mount the substrate; and a heating portion for heating the loading a substrate of the mounting portion; the air supply port is disposed in a plane view, and is disposed outside the substrate on the mounting portion in a circumferential direction to supply air into the processing container; and an outer peripheral exhaust port The plan view is disposed on the outer side of the substrate on the mounting portion along the circumferential direction for exhausting the inside of the processing container, and the central exhaust port is disposed at a central portion of the substrate on the mounting portion The upper side is for exhausting the inside of the processing container. The heat treatment apparatus according to claim 1, wherein one of the air supply port and the outer circumferential exhaust port is opened at a position higher than the substrate, and the other opening is at a position lower than the substrate to provide a An airflow curtain is formed in such a manner that the airflow flows into the airflow of the outer peripheral exhaust port to surround the substrate. The heat treatment device according to the second aspect of the invention, wherein the air supply port is provided with a portion that is opened at a position lower than the substrate, and the outer circumferential exhaust port is provided with a portion that is open at a position higher than the substrate. . A heat treatment device according to claim 2 or 3, wherein The gate member includes a switch for loading and unloading a substrate into and out of the processing container, and the air curtain is formed on a substrate side of the shutter member. The heat treatment apparatus according to any one of claims 1 to 4, wherein the time from the start of heating of the substrate until the elapse of the set time or the time when the temperature of the substrate exceeds the set temperature is a set point. It is configured to exhaust at least from the outer peripheral exhaust port, and to exhaust at least from the central exhaust port after the set time. The heat treatment apparatus according to claim 5, wherein the outer peripheral exhaust port and the central exhaust port are simultaneously exhausted at least from the start of heating of the substrate to the set time point. The heat treatment apparatus according to claim 5 or 6, wherein at least the set time is configured to simultaneously exhaust the outer peripheral exhaust port and the central exhaust port. The heat treatment apparatus according to any one of claims 5 to 7, wherein at least the set time point is such that the exhaust amount of the central exhaust port is larger than the exhaust amount of the outer peripheral exhaust port. The heat treatment apparatus according to any one of claims 5 to 8, wherein the exhaust of the outer peripheral exhaust port and the exhaust of the central exhaust port are The smaller one is configured to increase or decrease the exhaust gas increment as time passes. The heat treatment apparatus according to any one of claims 5 to 9, wherein the coating film contains a crosslinking agent, and after the setting, the crosslinking reaction by the crosslinking agent is completed. The time. The heat treatment apparatus according to any one of claims 1 to 10, wherein the ejector is provided with an ejector that sucks the exhaust gas flow by the flow of the gas for suction, and is connected to the exhaust passage via the exhaust path. The central exhaust port and the supply/stop mechanism for supplying and stopping the gas for suction of the injector. The heat treatment apparatus according to claim 11, wherein the heat treatment apparatus is provided with a mechanism for heating the gas for suction. The heat treatment apparatus according to claim 11 or 12, wherein the discharge side of the injector is connected to a downstream side exhaust path through which exhaust gas is exhausted, and a discharge side thereof is connected to the downstream side The exhaust path is provided with a virtual injector for attracting an atmosphere other than the flow path of the exhaust flow by the flow of the gas for suction, and the supply of the gas for suction is stopped by the supply/stop mechanism At this time, the gas for suction is configured to flow through the virtual injector. The heat treatment apparatus according to claim 13, wherein when the supply of the gas for suction is stopped in order to stop the suction of the exhaust gas flow, in order to suppress the exhaust gas from the central exhaust port, the central row is The exhaust path between the port and the aforementioned injector that attracts the exhaust flow is provided with a pressure loss portion. A heat treatment method for heat-treating a coating film formed on a substrate, characterized in that the substrate is placed on a mounting portion provided in a processing container for heating; and the substrate is At the time of the start of heating until the time when the set time elapses or the time when the temperature of the substrate exceeds the set temperature, that is, the set time point, at least from the substrate in the circumferential direction and on the outer side of the substrate on the mounting portion as viewed from the plane The outer peripheral exhaust port exhausts the inside of the processing container, and the gas is taken into the processing container from an air supply port that is disposed outside the substrate on the mounting portion in a circumferential direction as viewed in plan. After the setting time, the inside of the processing container is exhausted from at least a central exhaust port on the upper side of the central portion of the substrate provided on the mounting portion, and the gas supply port is opened from the air supply port The gas is taken into the work in the aforementioned processing vessel. The heat treatment method according to claim 15, wherein the substrate is disposed from the position higher than the substrate and lower than the substrate toward the other side so as to include the substrate by the exhaust of the outer peripheral exhaust port Air curtain. The heat treatment method according to claim 15 or 16, wherein the outer peripheral exhaust port and the central exhaust port are simultaneously exhausted at least from the start of heating of the substrate to the set time. The heat treatment method according to any one of claims 15 to 17, wherein at least the set time point is simultaneously exhausted by the outer peripheral exhaust port and the central exhaust port. A memory medium is a memory medium for storing a computer program for use in a device (the device is a mounting portion in which a substrate on which a coating film is formed is placed in a processing container and heat-treating the coating film); In the feature system, the computer program is programmed into a step group to perform the heat treatment method according to any one of claims 15 to 18.