JPH11121324A - Substrate-heating device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a substrate-heating device, wherein the entire substrate is heated to an even temperature in a short time. SOLUTION: A cover member 10 is provided above a heating plate 3 incorporating a heater. The cover member 10 comprises a process space cover 11 and a gas guide cover 12. The process space cover 11 is formed into a lid shape so as to cover the upper surface of the heating plate 3 and placed on the upper surface of the heating plate 3 to form a process space 18. The inside surface of a top plate part 11a and a sidewall part 11b of the process space cover 11 is formed into specular replication state. A heat ray A of radiation heat from the heating plate 3 is reflected on the inside surface of the specular top plate part 11a and a sidewall part 11b to heat a substrate W.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a substrate heating apparatus for heating a substrate to a predetermined temperature.

[0002]

2. Description of the Related Art A substrate heating apparatus is used in a process of processing a substrate such as a semiconductor wafer, a glass substrate for a photomask, a glass substrate for a liquid crystal display, and a substrate for an optical disk.
For example, in a photolithography process, a substrate heating device is used to heat a substrate on which a resist film is formed to a predetermined temperature.

FIG. 2 is a schematic diagram showing a schematic configuration of a conventional substrate heating apparatus. In FIG. 2, the substrate heating device includes a heating plate 21 inside a housing 20. Inside the heating plate 21, a heat source such as a heater is embedded.
Three spherical spacers 2 supporting the lower surface of the substrate W on the upper surface
8 are arranged.

Below the heating plate 21, three lifting pins 22 and a lifting frame 23 connected to these pins are arranged. A cylinder 24 is connected to one end of the elevating frame 23, and the substrate W is moved up and down by three elevating pins 22 in accordance with the expansion and contraction of the rod of the cylinder 24.

[0005] The cover member 2 is provided on the upper surface of the heating plate 21.
5 are arranged. The cover member 25 is a heating plate 2
The processing space 26 is formed by placing the cover member 25 on the upper surface of the heating plate 21 so as to be able to move up and down with respect to the upper surface of the heating plate 21.

When the substrate W is loaded and unloaded, the cover member 25
Then, the three lifting pins 22 are raised, and the substrate W is supplied onto the three lifting pins 22 through the substrate supply / discharge port 27 of the housing 20 or the substrate W on the lifting pins 22 is discharged.

At the time of heating the substrate, the substrate W is held close to the upper surface of the heating plate 21, and the cover member 25 is placed on the upper surface of the heating plate 21. Then, the substrate W is heated from the upper surface side of the heating plate 21 and is heated to a predetermined temperature. Thereby, a predetermined heat treatment is performed on the resist on the surface of the substrate W.

[0008] The substrate heating apparatus used for the above applications is required to uniformly heat the substrate W at a predetermined temperature. For example, a heat treatment (PEB:
In the postexposure bake process), it is important to uniformly heat the entire substrate W in order to make the line width of the pattern formed by exposure on the resist film uniform. In particular, in recent years, an exposure process using an excimer laser has been developed for forming finer patterns. In this excimer process, a chemically amplified resist is used. In the exposure process using a chemically amplified resist, an acid catalyst is generated in the resist film by an excimer laser, and the generated acid catalyst is heated by PEB treatment using a substrate heating device, diffused to accelerate the reaction, and to promote the reaction. A simple pattern is formed. For this reason, in the substrate heating device, it is necessary to uniform the heating state of the substrate W with high accuracy.

[0009]

However, in the above-described conventional substrate heating apparatus, the radiant heat generated from the upper surface of the heating plate 21 reaches the lower surface of the substrate W and is transmitted through the processing space 26, thereby causing the cover member 25 to move. And released to the outside. For this reason, the temperature in the processing space 26 becomes almost the set temperature near the upper surface of the heating plate 21, and becomes considerably lower than the set temperature above the processing space 26. For example, if the set temperature of the heating plate 21 is 110 ° C., the temperature above the processing space 26 is lower by about 30 ° C. or more. Therefore, in the processing space 26, an unstable temperature distribution is formed in which the lower part has a high temperature and the upper part has a low temperature.
For this reason, the temperature in the processing space 26 tends to fluctuate, and the temperature of the substrate W tends to be uneven.

Further, the amount of heat radiation from the cover member 25 is large, and it is difficult to raise and stabilize the temperature in the processing space 26 in a short time.

An object of the present invention is to provide a substrate heating apparatus capable of heating the entire substrate to a uniform temperature in a short time.

[0012]

Means for Solving the Problems and Effects of the Invention A substrate heating apparatus according to a first aspect of the present invention covers an upper portion of a base having a heat source with a lid member and is formed between the upper surface of the base and the lid member. In a substrate heating apparatus for holding and heating a substrate in a processing space, the inner surface of the lid member on the processing space side is formed in a mirror state.

[0013] In the substrate heating apparatus according to the first invention, the inner surface of the lid member that covers the upper part of the base is formed in a mirror state. Therefore, the heat rays radiated from the base side are reflected on the inner surface of the lid member in a mirror surface state, and are guided again to the substrate side to heat the substrate. The substrate is heated from the base side and is also heated from the inner surface side of the lid member by heat rays reflected on the inner surface of the lid member. Thereby, the substrate can be heated to the predetermined temperature in a short time.

Further, the amount of heat released to the outside of the cover member is reduced by reflecting the heat rays on the inner surface of the cover member. For this reason, the temperature is raised near the inner surface of the lid member as well as on the upper surface side of the base, and the temperature distribution in the processing space is made uniform. This makes it possible to heat the substrate to a predetermined temperature uniformly in a short time.

Here, the "mirror state" means that the surface roughness is J.
The center line average roughness RA defined in IS B0601 is 0.3 or less.

According to a second aspect of the present invention, there is provided the substrate heating apparatus according to the first aspect of the present invention, wherein the lid member is held in the processing space and the top plate facing the upper surface of the base. And a side wall portion surrounding the outer periphery of the substrate, and the inner surface of the top plate portion is formed in a mirror surface state.

In this case, the heat rays radiated from the base side are reflected by the inner surface of the top plate portion, reach the substrate, and heat the substrate. Thereby, the substrate can be heated to the predetermined temperature in a short time, and the temperature distribution in the processing space is made uniform, whereby the substrate can be heated uniformly.

According to a third aspect of the present invention, in the substrate heating apparatus according to the second aspect of the present invention, the inner surface of the side wall portion is further formed in a mirror state.

In this case, in addition to the heat rays reflected on the inner surface of the top plate, the heat rays reflected on the inner surface of the side wall are also guided to the substrate to heat the substrate. Thus, the substrate can be uniformly heated to a predetermined temperature in a short time.

[0020]

FIG. 1 is a sectional view of a substrate heating apparatus according to an embodiment of the present invention. The substrate heating device includes an upper housing 1
And a heating plate 3 for heating the substrate W inside the lower housing 2. A heat source such as a heater is embedded inside the heating plate 3. On the upper surface of the heating plate 3, three spherical spacers 16 supporting the lower surface of the substrate W are provided.
Are arranged in an equilateral triangle. Further, the heating plate 3 is formed with three through holes 17 for passing three lifting pins 4 for moving the substrate W up and down.

Below the heating plate 3, three lifting pins 4 and a lifting frame 5 connected thereto are arranged. A cylinder 6 is connected to one end of the lifting frame 5 at a position outside the lower housing 2. Then, the elevating frame 5 and the elevating pins 4 are moved up and down by the expansion and contraction of the rod of the cylinder 6.

A substrate supply / discharge port 9 is formed on the front surface of the upper housing 1. A shutter 8 is disposed inside the substrate supply / discharge port 9. The lower end of the shutter 8 is linked to the lifting frame 5 by an interlocking member 7. As a result, when the rod of the cylinder 6 is extended, the elevating frame 5 is raised to raise the substrate W above the heating plate 3, and the shutter 8 is lowered to open the substrate supply / discharge port 9. When the rod of the cylinder 6 is retracted, the elevating frame 5 is lowered, the substrate W is placed on the spherical spacer 16, the shutter 8 is raised, and the substrate supply / discharge port 9 is closed.

A cover member 1 is provided above the heating plate 3.
0 is arranged. The cover member 10 is provided on the upper surface of the processing space cover 11 and a processing space cover 11 that forms a processing space 18 between the heating member 3 and the upper surface of the heating plate 3.
A gas introduction cover 12 forming a gas introduction space 14 is formed, and is formed so as to be able to move up and down with respect to the heating plate 3 by elevating means (not shown).

The processing space cover 11 is made of a material such as stainless steel or aluminum. The top plate 11a faces the upper surface of the heating plate 3, and extends vertically downward from the outer peripheral edge of the top plate 11a. It is formed in a lid shape having a side wall 11b surrounding the outer periphery. The inner surface of the top plate 11a and the inner surface of the side wall 11b of the processing space cover 11 are formed in a mirror surface state. As a mirror surface state,
For example, the surface roughness of the inner surface is 0.3 or less in center line average roughness RA specified in JIS B0601.

The top plate 11 of the processing space cover 11
In a, a number of small holes 13 communicating with the gas introduction space 14 are formed. A gas inlet 15 is provided on a side surface of the gas inlet cover 12. Further, the gas inlet 15
Is connected to a gas introduction path (not shown). Accordingly, during the heat treatment of the substrate, a gas such as nitrogen is introduced into the gas introduction space 14 from the gas introduction port 15 and further supplied into the processing space 18 through the small holes 13 of the processing space cover 11.

In this embodiment, the heating plate 3 corresponds to a base of the present invention, and the processing space cover 11 corresponds to a lid member.

When the substrate W is carried in, the rod of the cylinder 6 is extended, the shutter 8 is lowered, and the lifting pin 4 is raised. Then, the substrate W is transferred to the elevating pins 4 through the substrate supply / discharge port 9 of the upper housing 1 by the substrate transfer device arranged outside. At this time, the cover member 10 has been moved above the heating plate 3 by the elevating means.

After the substrate W is delivered to the lifting pins 4, the rod of the cylinder 6 is retracted, the lifting pins 4 are lowered, and the substrate W is placed on the spherical spacer 16 of the heating plate 3. At the same time, the shutter 8 moves up, and the substrate supply / discharge port 9 is closed. Further, the cover member 10 is lowered, and the processing space 1
8 is closed. In this state, the heat treatment of the substrate W is started.

During the heating process, the substrate W is heated by supplying radiant heat from the upper surface of the heating plate 3 to the substrate W by the heat source in the heating plate 3. The heat rays A of radiant heat emitted from the upper surface of the heating plate 3 and the surface of the substrate W pass through the processing space 18 and reach the inner surface of the top plate 11a or the side wall 11b of the processing space cover 11. The inner surfaces of the top plate 11a and the side wall 11b are mirror-finished. Therefore, the heat ray A is reflected by the inner surfaces of the top plate 11a and the side wall 11b, reaches the surface of the substrate W again, and heats the substrate W.

When the heating process of the substrate is completed, the substrate W is moved in the substrate supply / discharge port 9 of the upper housing 1 by an operation reverse to the operation of loading the substrate.
And is discharged outside.

As described above, by forming the inner surfaces of the top plate 11a and the side wall 11b of the processing space cover 11 into a mirror surface, the heat rays A emitted from the heating plate 3 or the substrate W are reflected to the substrate W side. be able to. Therefore, the substrate W is heated not only from the heating plate 3 side but also from the inner surface side of the processing space cover 11, and the temperature is raised to a predetermined set temperature in a short time.

Further, the heat rays A are reflected by the inner surface of the top plate 11a and the side wall 11b of the processing space cover 11, so that the amount of heat released from the processing space 18 to the outside through the processing space cover 11 is reduced. . Therefore, the temperature in the processing space 18 rises in a short time and the processing space 1
The temperature also rises equally in the upper part of 8. Thereby, the temperature distribution in the processing space 18 is made uniform, and the temperature distribution can be made uniform over the entire substrate W.

Further, the top plate 1 of the processing space cover 11
Nitrogen gas is uniformly supplied into the processing space 18 through a number of small holes 13 provided in 1a. Thereby, the atmosphere in the processing space 18 is stirred, and the temperature distribution is further uniformed.

In the above embodiment, the inner surfaces of the top plate 11a and the side wall 11b of the processing space cover 11 are formed in a mirror state, but at least the inner surface of the top plate 11a is formed in a mirror state. Thereby, an effect of making the in-plane temperature distribution of the substrate W uniform can be obtained.

The top plate 11 of the processing space cover 11
In order to reduce the amount of heat released to the outside through the a or the side wall portion 11b, the thickness of the processing space cover 11 is increased, or a plate-like member is laminated on the outer surface of the processing space cover 11 in multiple layers. Is also good. This also allows the processing space 18
The temperature distribution in the inside can be made uniform, and the in-plane temperature distribution of the substrate W can be made more uniform.

[Brief description of the drawings]

FIG. 1 is a sectional view of a substrate heating apparatus according to an embodiment of the present invention.

FIG. 2 is a schematic diagram showing a schematic configuration of a conventional substrate heating device.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Upper housing 2 Lower housing 3 Heating plate 10 Cover member 11 Cover for processing space 11a Top plate part 11b Side wall part 12 Cover for gas introduction 18 Processing space A Heat wire

Claims (3)

[Claims] 1. A substrate heating apparatus for covering an upper portion of a base having a heat source with a lid member, and holding and heating the substrate in a processing space formed between an upper surface of the base and the lid member, A substrate heating device, wherein an inner surface of the lid member on the processing space side is formed in a mirror surface state. 2. The lid member has a top plate facing the upper surface of the base, and a side wall surrounding an outer periphery of the substrate held in the processing space, and an inner surface of the top plate. 2. The substrate heating apparatus according to claim 1, wherein the substrate is formed in a mirror state. 3. The substrate heating apparatus according to claim 2, wherein an inner surface of said side wall portion is further formed in a mirror state.