JPH07152158A - Substrate heater - Google Patents

Abstract

PURPOSE:To obtain a pattern size having good intra-surface uniformity by providing a substrate heater with a hot plate having a heater, a lower cap enclosing this hot plate, an upper cap having a circular conical-shaped inside surface and a gas introducing pipe disposed in this lower cap, thereby uniformly heating a substrate. CONSTITUTION:The lower cap 3 and the upper cap 4 are so pressed as to prohibit the inflow of cold air from sideways and enclose the hot plate 1 heated by a heater 2. The gas introducing pipe 7 consisting of metal is disposed between the lower cap 3 and the hot plate 1 and a slight amt. of gaseous nitrogen is sufficiently heated and introduced by the introducing pipe 7 from an air suction port 8 and is discharged from discharge ports 9a to 9d. The inside surface 5 of the upper cap 4 is formed to the circular conical shape having a gentle inclination, for example, an inclination of about 10 deg., by which a base body contg. an org. solvent of the heated resist is gently risen and is discharged from a discharge port 6 at the top. Further, a photomask 10 is placed on the hot plate 1 by lifting the upper cap 4 upward by a driving mechanism. At this time, the temp. is maintained more uniformly as the upper space of the photomask 10 is smaller and, therefore, uniform baking is possible.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a heating device for heating photomasks for semiconductors and liquid crystal panels or substrates for semiconductors and liquid crystal panels.

[0002]

2. Description of the Related Art A semiconductor photomask will be described as an example. The latest semiconductor photomask is formed by sputtering a chromium film of about 1000 angstrom on a glass substrate of 152 mm square and a thickness of 6.3 mm, applying a resist on it, drawing a pattern with an electron beam drawing device, and then developing the resist. Then, the chrome film is etched and the resist is stripped off to complete the process.

Chemically amplified resists have been developed and put into practical use as resists which are highly dry-etching resistant and highly accurate resist patterns can be obtained as the degree of integration of LSIs increases and patterns become finer. A typical product is SAL601 from Shipley.

After the chemically amplified resist is drawn with an electron beam,
Since baking is performed at about 110 ° C. to amplify the sensitivity of the resist, the pattern size changes depending on the temperature uniformity during baking.

In the conventional heating device, since the upper side of the heating plate is open, when the photomask is placed on the heating plate and heated, a large loop of air convection is generated on the photomask, and the temperature of the photomask is 3 to. There is a defect that dimensional accuracy deteriorates due to a change of 5 ° C.

There is also a baking apparatus having an upper cover added, but it has a defect that the temperature of the photomask, which is the substrate to be processed, is likely to change due to the large air gaps on the side surfaces and the cold air flowing from there. Further, there is a defect that an turbulent flow of air is generated and the organic solvent generated when the resist is baked reattaches to the photomask as particles to cause a pattern defect.

[0007]

SUMMARY OF THE INVENTION An object of the present invention is to provide a substrate heating apparatus capable of uniformly heating a substrate and obtaining a pattern dimension with good in-plane uniformity.

Another object of the present invention is to provide a substrate heating apparatus in which particles do not adhere and pattern defects do not occur.

[0009]

SUMMARY OF THE INVENTION According to the present invention, a heating plate having a heater, a lower lid for enclosing the heating plate, an abutment for the lower lid and an exhaust hole in a central portion, and an inner surface having a conical upper portion are provided. It is characterized in that it comprises a lid and a gas introducing pipe arranged inside the lower lid.

[0010]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below with reference to the drawings. Figure 1
a is a vertical cross-sectional view of a front view of the substrate heating apparatus of the present invention, FIG.
Is a plan view.

The heating plate 1 is heated by the heater 2 and, for example, 110
The temperature is adjusted to ℃. The lower lid 3 and the upper lid 4 are abutted against each other so that cold air does not flow in from the side, and the hot plate 1 is included therein.

A metal gas introduction pipe 7 is arranged between the lower lid 3 and the heating plate 1, and 100 to 1000 cc / in from the intake port 8.
Minute amount of nitrogen gas is sufficiently heated by the introduction pipe 7 and introduced,
Discharge from the discharge ports 9a to 9d.

The inner surface 5 of the upper lid 4 has a gentle slope, for example 1
By forming the conical shape with an inclination of about 0 degree, the heated gas containing the organic solvent of the resist gradually rises and is exhausted from the exhaust port 6 at the top.

The photomask 10 is mounted on the heating plate 1 by raising the upper lid 4 by a driving mechanism (not shown).
The smaller the upper space of the photomask 10 is, the more uniform the temperature is, so that uniform baking becomes possible. When the distance between the heating plate 1 and the upper lid 4 is set to 20 mm or less, the temperature stability increases, and the in-plane temperature difference when the 152 mm square photo mask is placed and baked at 110 ° C. is 1 ° C. .

Further, the number of particles when nitrogen of 500 cc / min was sucked from the suction port 8 was reduced to 5 particles / mask from the conventional 5 particles / mask.

In the above description, the case where the lower lid body 3 and the upper lid body 4 directly contact each other has been described. However, by sandwiching the tetrafluoride resin between them, the airtightness is further increased, and the inflow of cold air from the side. Can be completely prevented.

In the above description, the case where the resist is a chemically amplified resist is described, but the present invention is not limited to this, and it is apparent that the present invention can be applied in the same manner to a resist which requires a uniform baking temperature. Is.

In the above description, the photomask is taken as an example, but it is obvious that the same can be realized with a semiconductor substrate and a liquid crystal panel substrate.

[0019]

As described above, the present invention has the following effects. By heating the substrate uniformly, a pattern dimension with good in-plane uniformity can be obtained. In addition, high quality baking without particle adhesion is possible.

[Brief description of drawings]

FIG. 1a is a vertical sectional view of a front view of a substrate heating apparatus of the present invention.

FIG. 1b is a plan view of the substrate heating apparatus of the present invention.

[Explanation of symbols]

1 ... Hot plate, 2 ... Heater, 3 ... Lower lid, 4 ... Upper lid,
5 ... inner surface, 6 ... exhaust port, 7 ... gas inlet pipe, 8 ... intake port,
9a to 9d ... Discharge port, 10 ... Photomask.

Claims (3)

[Claims] 1. A heating plate having a heater, a lower lid that encloses the heating plate, an upper lid that abuts against the lower lid and has an exhaust hole in a central portion, and an inner surface is conical, and an inside of the lower lid. A substrate heating device, comprising: 2. The distance between the heating plate and the upper lid is 20.
The substrate heating device according to claim 1, wherein the substrate heating device has a thickness of not more than mm. 3. The substrate heating apparatus according to claim 1, wherein a fluororesin is inserted into a contact portion between the lower lid and the upper lid.