JP2001168012A - Heat treatment device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To reduce the quantity of dry air to be used for lowering a temperature. SOLUTION: Concerning the heat treatment device for applying a heat treatment to a wafer W, this device is provided with a hot plate 1 for placing the wafer W, heating element 1 for heating the hot plate 1, cooling jacket 5 which has an injection port 7 for injecting a gas for cooling and for cooling the hot plate 1, gas piping 13 for communicating the injection port 7 of the cooling jacket 5 and a cooling gas feeding source 15, and air cooler 20 provided on the gas piping 13 for controlling the temperature of the gas for cooling (dry air), which flows in the gas piping 13.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a semiconductor wafer, a glass substrate for a liquid crystal display, a glass substrate for a photomask,
The present invention relates to a heat treatment apparatus that places a substrate such as a substrate for an optical disk on a heat plate and heat-treats the substrate.

[0002]

2. Description of the Related Art As a conventional heat treatment apparatus, there is known a heat treatment apparatus in which a heating element such as a mica heater is buried under a thick heat plate formed of a metal material having good heat conductivity (for example, aluminum). I have. In such a heat treatment apparatus, the entire heat plate is heated to a processing temperature for heat treatment by a heating element, and a heat treatment is performed on a wafer mounted on a mounting surface of the heat plate.

In recent heat treatment apparatuses such as a high-speed elevating and lowering temperature baking furnace, it takes a long time to change the processing temperature only with the above-described heating element. Therefore, a cooling mechanism is interposed between the heating plate and the heating element. Let me. Then, the heating element and the cooling mechanism are individually controlled to change the temperature of the heating plate to a desired processing temperature. In the cooling mechanism at this time, the plate is cooled using dry air in a clean room as a cooling gas.

[0004]

However, dry air used in a clean room is originally 23 ° C.
Since the temperature is about 25 ° C., a large amount of dry air needs to be used when rapidly reducing the temperature of the hot plate as in a high-speed elevating temperature baking furnace. For this reason, there is a problem that a burden on a factory worker of a person who uses the heat treatment apparatus is increased.

The present invention has been made in view of such circumstances, and has as its object to provide a heat treatment apparatus capable of reducing the amount of a cooling gas such as dry air used at the time of cooling.

[0006]

According to another aspect of the present invention, there is provided a heat treatment apparatus for performing heat treatment on a substrate, comprising: a heat plate on which the substrate is placed; A heating plate heating means for heating the heating plate, an injection port into which a cooling gas is injected, a heating plate cooling means for cooling the heating plate, and an injection port of the heating plate cooling means and a cooling gas supply source. It is characterized by comprising: a gas pipe to be communicated; and a temperature adjusting means provided in the gas pipe and adjusting a temperature of a cooling gas flowing through the gas pipe.

The heat treatment apparatus according to claim 2 is the heat treatment apparatus according to claim 1, wherein the temperature adjustment means includes a cooling gas cooling means for cooling a cooling gas flowing through the gas pipe. It is characterized by having.

The heat treatment apparatus according to a third aspect of the present invention is the heat treatment apparatus according to the second aspect, wherein both sides of the temperature adjusting means are connected to the gas pipe to flow a cooling gas. Further comprising a flow path, wherein the cooling gas cooling means has a portion along the first flow path, and has a second flow path through which a fluid for cooling the cooling gas flows. It is a feature.

The heat treatment apparatus according to claim 4 is the heat treatment apparatus according to claim 3, wherein the first flow path is
It has a meandering portion, and the second flow passage has a meandering portion along the meandering portion of the first flow passage.

The heat treatment apparatus according to claim 5 is the heat treatment apparatus according to claim 3 or 4, wherein the fluid flowing through the second flow path for cooling the cooling gas is Freon. It is characterized by the following.

A heat treatment apparatus according to a sixth aspect is the heat treatment apparatus according to any one of the first to fifth aspects, wherein the temperature adjustment means is provided in the gas pipe and the temperature is adjusted by the temperature adjustment means. Temperature detecting means for detecting the temperature of the cooling gas flowing through the gas pipe, wherein the temperature adjusting means heats the cooling gas based on the temperature detected by the temperature detecting means. A heating means is provided.

Further, the heat treatment apparatus according to claim 7 is
The heat treatment apparatus according to claim 1, wherein the heat plate heating means is provided below the heat plate, and the heat plate cooling means is provided below the heat plate heating means. It is characterized by the following.

[0013]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, an embodiment of a heat treatment apparatus according to the present invention will be described with reference to the drawings. FIG. 1 is a diagram showing a schematic configuration of a heat treatment apparatus according to the present invention, and FIG. 2 is a plan view of a heat plate.

As shown in FIG. 1, in this heat treatment apparatus, four processing units 10a, 10b, 10c and 10d are arranged for performing a heat treatment on a wafer W which is a kind of substrate. Each of these processing units 10a, 10b, 10c,
10d all have the same structure, and therefore, in the present embodiment, a description will be given below based on the processing unit 10a.

The processing section 10a is provided with a heat plate 1 on which a wafer W is placed. The heat plate 1 is made of a metal material having good heat conductivity, such as aluminum, in a circular shape in plan view. (See FIG. 2), and is formed relatively thick to increase the heat capacity. A heating element 3 such as a mica heater is provided on the lower surface.
Is attached. The heating element 3 corresponds to a heating plate heating unit.

Although not shown, three spheres are fitted on the upper surface of the heat plate 1. Therefore, when the wafer W is placed on the heat plate 1, the three spheres hold the wafer W in a state where a minute gap called a proximity gap is maintained from the upper surface (placement surface) of the heat plate 1. The wafer W is supported on the back surface, and is configured to uniformly heat the wafer W by radiant heat from the upper surface of the heat plate 1. Of course, the heat treatment may be performed by directly mounting the wafer W on the upper surface of the heat plate 1.

On the lower surface of the heating element 3, a cooling jacket 5 corresponding to a hot plate cooling means is further provided.
Specifically, four inlets 7 for injecting a cooling gas such as dry air are provided on the lower surface of the cooling jacket 5. As shown in FIG. 2, these injection ports 7 are formed so as to be substantially symmetric about a central portion C in plan view. Further, four outlets 9 are formed on the peripheral edge side from each inlet 7, and one inlet 7 and one outlet 9 are connected to each other through a flow path 11. Each flow path 11 is formed in a zigzag shape to increase the area in contact with the cooling jacket 5.

As described above, in the present embodiment, since the heating element 3 is interposed between the heat plate 1 and the cooling jacket 5, it is difficult for the influence of the temperature distribution of the cooling jacket 5 to be directly transmitted to the heat plate 1. . Therefore, it is possible to lower the temperature of the wafer W while keeping the uniformity of the temperature distribution on the upper surface of the heat plate 1 good.

Further, since the cooling gas is injected from the four inlets 7, the length of one flow path 11 can be shortened, and the temperature difference between the cooling gas at the time of injection and the temperature at the time of discharge is reduced. can do. Further, since the temperature change due to the cooling gas spreads concentrically and substantially uniformly from each of the four inlets 7, the temperature distribution in the heat plate 1 can be further uniformed.

Each inlet 7 is connected to a cooling gas supply source 15 via a gas pipe 13. The gas pipe 13 has a flow control valve 17 and a first solenoid on-off valve 19a.
, An air cooler 20 and a fifth solenoid on-off valve 21 are provided. The cooling gas supply source 15 is used not only for the processing unit 10a but also for the other processing units 10b and 10b.
Also used for c and 10d. Therefore, each of the gas pipes 13 connected to the other processing units 10b, 10c, and 10d is provided with a second electromagnetic on-off valve 19b, a third electromagnetic on-off valve 19c, and a fourth electromagnetic on-off valve 19d, respectively. .

As the cooling gas supplied from the cooling gas supply source 15, for example, dry air from a dry air supply source generally provided as a utility for a clean room can be used, and 100 Nl (normal liter) per minute is used. Supply by

Next, a specific configuration of the air cooler 20 will be described. FIG. 3 is a diagram showing a schematic configuration of the air cooler. The air cooler 20 corresponds to a temperature adjusting unit.

The air cooler 20 is connected to the gas pipe 13 and has a supply port 201 for supplying a cooling gas into the air cooler 20 and a cooling gas temperature-controlled in the air cooler 20. And a discharge port 202 for discharging from inside. In the air cooler 20, the cooling gas supplied from the supply port 201 is:
As indicated by a solid arrow, the air is discharged from the outlet 202 through a gas pipe 203 corresponding to a first flow path in the air cooler 20. The gas pipe 203 is connected to the air cooler 2.
It has a meandering portion in 0. An annular CFC pipe 204 having a meandering portion along the meandering portion of the gas pipe 203 is provided. The fluorocarbon pipe 204 corresponds to the second flow path.

In the middle of the CFC pipe 204, a compressor 205 is provided on the upstream side, and a cooling unit 206 is provided on the downstream side. The cooling unit 206 includes a cooling fin 207 disposed around the fluorocarbon pipe 204,
A cooling fan 208 for sending cool air to the cooling fins 207;

At a position downstream of the meandering portion of the gas pipe 203, a heater 209 is provided which flows through the gas pipe 203 and raises the temperature of the cooling gas once temperature-controlled. Outlet 20 of gas pipe 203
In the vicinity of 2, a detection sensor 210 for detecting the temperature of the cooling gas flowing through the gas pipe 203 is provided.

Next, a control system of the heat treatment apparatus according to the present invention will be described. FIG. 4 is a diagram showing a control system of the heat treatment apparatus according to the present invention. Control of each part of this heat treatment device
This is performed by the control unit 30 as shown in FIG. The control unit 30 includes a heating element 3, a flow control valve 17, a first solenoid on-off valve 19a, a second solenoid on-off valve 19b, and a third solenoid on-off valve 19
c, the fourth electromagnetic on / off valve 19d, the fifth electromagnetic on / off valve 21, the compressor 205, the cooling fan 208, the heater 209, and the detection sensor 210, respectively.

The control unit 30 controls the heating of the wafer W by the heating element 3, the control of the flow rate of the cooling gas by the flow rate control valve 17, the first solenoid on / off valve 19a, the second solenoid on / off valve 19b, and the third solenoid. On-off valve 19c, fourth electromagnetic on-off valve 19
d, control of supply / stop of cooling gas by the fifth solenoid on-off valve 21, control of compressor 205, and cooling fan 2
08 rotation control is performed. Further, the control unit 30
Has a CPU 31 and controls heating of the heater 209 based on the temperature detected by the detection sensor 210.
In this embodiment, if the temperature detected by the detection sensor 210 is equal to or lower than 12 ° C., the heater 209 is set to start heating.

Next, the operation of supplying the cooling gas and the operation of adjusting the temperature of the cooling gas will be described. First, the control unit 30
When the fifth solenoid on-off valve 21 is switched from the “closed” state to the “opened” state by the control described above, the cooling gas flows out of the gas pipe 13 from the cooling gas supply source 15. Gas piping 13
The cooling gas flowing through the supply port 20 of the air cooler 20
1 to the air cooler 20. At this time, the temperature of the cooling gas supplied from the supply port 201 is about 25
° C.

The cooling gas is supplied from the supply port 201 into the air cooler 20, flows through the gas pipe 203, and is discharged from the discharge port 202 to the outside of the air cooler 20 as follows. The cooling process of the cooling gas is performed in the air cooler 20. First, CFC piping 2
The gaseous Freon flowing through 04 is compressed by the compressor 205 and changes the gaseous Freon into liquid Freon. Since the temperature of the liquid Freon rises during the change, the cooling unit 20
6, while flowing the liquid Freon through the Freon pipe 204 around which the cooling fins 207 are arranged,
Control, the cooling fan 208 is rotated to lower the temperature of the liquid Freon.

The liquid Freon cooled by the cooling unit 206 flows to the meandering part of the Freon pipe 204, and the temperature of the cooling gas flowing through the gas pipe 203 is lowered. By the cooling process of the cooling gas, the cooling gas is lowered from 25 ° C. to 15 ° C. On the other hand, when performing the cooling process of the cooling gas, the temperature of the liquid Freon rises, and the liquid Freon changes to gas Freon. The changed gas CFC flows to the compressor 205 again.

The cooled cooling gas is supplied to the gas pipe 2
03 to the air cooler 202 from the outlet 202
It is discharged outside. The temperature of the cooling gas immediately before being discharged from the outlet 202 of the air cooler 20 is detected by a detection sensor 210 provided near the outlet 202. If the temperature at this time is about 15 ° C., there is no problem.
If the temperature is lower than 0 ° C., the cooling gas may be dewed in the gas pipe 203. Therefore, the temperature of the detection sensor 21
If 0 is detected, the heater 209 is turned on by the CPU 31 of the control unit 30, and the cooling gas is heated so that the temperature of the cooling gas becomes 15 ° C.

If the flow rate of the cooling gas discharged from the discharge port 202 is adjusted by the flow rate control valve 17 while the first solenoid on-off valve 19a is in the "open" state, for example, the cooling gas is supplied to the injection port 7 of the processing section 10a. The hot plate 1 is injected and the cooling gas flows in the flow path 11 to lower the temperature of the heat plate 1.

According to the heat treatment apparatus of the present invention, the following effects can be obtained.

First, since an air cooler 20 is provided in the gas pipe 13 to cool the cooling gas or the like to control the temperature, the amount of dry air used at the time of cooling can be reduced, and the plant of the person using the heat treatment apparatus can be reduced. This has the effect of reducing the burden on utility.

An annular CFC having a meandering portion in the gas pipe 203 through which the cooling gas flows, and a portion meandering in the same manner along the meandering portion of the gas pipe 203. Since the pipe 204 is provided, the cooling gas can be efficiently cooled by a fluid such as Freon.

Further, the temperature of the cooling gas immediately before being discharged from the discharge port 202 of the air cooler 20 is detected by the detection sensor 210 provided in the vicinity of the discharge port 202. For example, since the heater 209 is turned on by the CPU 31 of the control unit 30 and the cooling gas is heated so that the temperature of the cooling gas becomes 15 ° C., the condensation of the cooling gas in the gas pipe 203 is reduced. Can be prevented.

The heat treatment apparatus according to the present invention can be modified as follows. In the above-described embodiment, the four injection ports 7 are formed so as to be equidistant from the central portion C. For example, the plurality of injection ports 7 are
If the temperature distribution uniformity is not significantly disturbed, it is not necessary to form them at equal distances.

It is not essential to provide a plurality of injection ports 7, and only one injection port 7 may be provided in the central portion C.

Further, in the above-described embodiment, the four inlets 7 are formed in the cooling jacket 4 at the same distance from the central portion C. In addition, the inlets may be provided in the central portion C as well. Good.

[0040]

As described above in detail, according to the heat treatment apparatus of the present invention, the cooling gas flowing through the gas pipe is connected to the gas pipe connecting the inlet of the hot plate cooling means and the cooling gas supply source. Since the temperature adjusting means for adjusting the temperature is provided, the amount of dry air used at the time of cooling can be reduced.

[Brief description of the drawings]

FIG. 1 is a view showing a schematic configuration of a heat treatment apparatus according to the present invention.

FIG. 2 is a plan view of a heat plate.

FIG. 3 is a diagram showing a schematic configuration of an air cooler.

FIG. 4 is a diagram showing a control system of the heat treatment apparatus according to the present invention.

[Explanation of symbols]

 W Wafer 1 Heat plate 3 Heating element 5 Cooling jacket 7 Inlet 10a Processing unit 10b Processing unit 10c Processing unit 10d Processing unit 11 Flow path 13 Gas flow path 15 Cooling gas supply source 20 Air cooler 30 Control unit 31 CPU 203 Gas pipe 204 CFC piping 205 Compressor 206 Cooling unit 207 Cooling fin 208 Cooling fan 209 Heater 210 Detection sensor

Claims (7)

[Claims] 1. A heat treatment apparatus for performing heat treatment on a substrate, comprising: a heat plate on which the substrate is placed; a heat plate heating means for heating the heat plate; and an inlet through which a cooling gas is injected. A heat plate cooling means for cooling the heat plate; a gas pipe for communicating an inlet of the heat plate cooling means with a cooling gas supply source; and a cooling gas flowing in the gas pipe provided in the gas pipe. A heat treatment apparatus comprising: a temperature adjusting unit that adjusts a temperature. 2. The heat treatment apparatus according to claim 1, wherein said temperature adjusting means includes cooling gas cooling means for cooling a cooling gas flowing through said gas pipe. 3. The heat treatment apparatus according to claim 2, wherein the temperature adjusting means further includes a first flow path connected on both sides to the gas pipe and through which a cooling gas flows. A heat treatment apparatus, wherein the cooling means has a portion along the first flow path, and includes a second flow path through which a fluid for cooling the cooling gas flows. 4. The heat treatment apparatus according to claim 3, wherein the first flow path has a meandering part, and the second flow path is a meandering state of the first flow path. A heat treatment apparatus having a meandering portion along a curved portion. 5. The heat treatment apparatus according to claim 3, wherein the fluid flowing through the second flow path for cooling the cooling gas is:
A heat treatment apparatus characterized by being CFCs. 6. The heat treatment apparatus according to claim 1, wherein the cooling gas is provided in the gas pipe, the temperature is adjusted by the temperature adjusting means, and the cooling gas flows through the gas pipe. Temperature detecting means for detecting the temperature of the cooling medium, wherein the temperature adjusting means includes cooling gas heating means for heating the cooling gas based on the temperature detected by the temperature detecting means. Heat treatment equipment. 7. The heat treatment apparatus according to claim 1, wherein said heating plate heating means is provided below said heating plate, and said heating plate is provided below said heating plate heating means. A heat treatment apparatus comprising cooling means.