JPS6022130A - Device for protecting photomask for exposure - Google Patents

Abstract

PURPOSE:To prevent dew condensation on the transparent protective sheet of a protecting device and the production of a strain in the sheet and to enable the exact transfer of a pattern by piercing plural fine ventholes in the support frame of the device so as to make the temp. and humidity of the internal air equal to those of the open air. CONSTITUTION:Plural fine ventholes 12 of <=500mum diameter are pierced in the horizontal support frame of a photomask protecting device 10 so that they are tapered from the outside of the side wall toward the inside. The device 10 is adhered to the glass substrate 6 of a photomask 5 with an adhesive 4 to protect the pattern 7. The ventholes 12 pierced in the frame 10 make the temp. and humidity of the air in the device 10 equal to those of the open air, so dew condensation is not caused on the transparent protective sheet 3, and no strain is produced in the sheet 3. Since the ventholes 12 are fine, the penetration of dust from the outside can be prevented.

Description

Detailed Description of the Invention [Technical Field of the Invention] The present invention relates to a protection device for an exposure photomask used in the manufacture of semiconductor devices such as integrated circuits. It was designed to be shown in sectional and perspective views in FIGS. 1 and 2. The photomask protective equipment fittll is as follows. (
2) is a support frame with an open top and bottom, and (3) is a transparent protection plate made of an optically transparent material such as nitrocellulose and fixed to the upper part of the support frame (2).

(5) is a photomask for exposure, and a glass substrate (6)
A thin metal film pattern (7) is formed on the upper surface of the substrate.

When manufacturing a semiconductor integrated circuit device, this photomask (5) is generally used to repeatedly transfer a thin film pattern (7) onto a semiconductor wafer (not shown) 8 to 10 times.

By the way, when transferring a pattern onto a wafer using this photomask (6), if foreign matter such as dust adheres to the glass substrate (6) or if the thin film pattern (7) is damaged due to improper handling, the wafer may be damaged. - up to that t
t transcribed. This results in pattern defects on the wafer, which greatly reduces the yield of semiconductor integrated circuit devices. In addition, in the so-called step-and-repeat method in which semiconductor integrated circuit elements are transferred one by one onto a wafer in the form of a board pattern, foreign matter such as dust adhering to the glass substrate (6) and defects in the pattern (7) can be removed. All the defects are transferred to the semiconductor integrated circuit elements and become a common defect, making it impossible to produce good products on the wafer.

In order to eliminate this, as shown in Figure 1, a photomask (
A photomask protector (!) is bonded onto the glass substrate (6) of 6) with an adhesive (4).

The conventional photomask protection device I (11) hermetically surrounds the area of the pattern (7) of the photomask (5), which creates a difference in temperature and humidity between the inside air and the outside air. Therefore, dew droplets may adhere to the transparent protection plate (3), or distortion may occur in the transparent protection plate 111 due to the pressure difference between the inside and outside air due to temperature rise, which may hinder the normal transfer of the pattern onto the semiconductor wafer. there were.

[Summary of the invention]

This invention provides a support frame with small ventilation holes that penetrate inside and outside,
It is an object of the present invention to provide a protection device for an exposure photomask that eliminates the difference in temperature and humidity between inside air and outside air, prevents dew droplets from adhering to a transparent protection plate and generates distortion, and allows accurate transfer of a pattern onto a semiconductor wafer. The purpose is

[Embodiments of the invention]

FIG. 3 and FIG. 5 are a sectional view and a perspective view showing a photomask protection device according to an embodiment of the present invention.
(The threat is the same as the conventional device described above. Photomask protection @ (Lull is the support frame (1
1) A plurality of small ventilation holes +121 are provided on the side portion of the housing 1), which penetrate inside and outside. These small holes have a diameter of, for example, 5
It has a micro diameter of 00μ or less, and has a large tapered hole on the outside.

The above-mentioned candy packaging @ (101) is adhered to the glass substrate (6) of the 7 otomask (5) with an adhesive (4).

In the device of the above-mentioned embodiment, the small diameter ventilation hole provided in the support frame (11) eliminates the difference in temperature and humidity between the inside of the photomask protection device and the outside air.

This prevents dew condensation or distortion from occurring on the transparent protective plate. Also, ventilation holes (12)
The diameter of the hole is minute and prevents dust from entering from the outside, and by making the hole larger on the outside, the dust prevention effect can be further improved.

In the above embodiment, the ventilation hole 021 is made into a tapered hole, but it may be made into a non-tapered ventilation hole. In addition, the ventilation holes are made at an angle with the inner position higher than the outer height.
Shinfoot: The intrusion prevention effect may be increased.

Further, in the above embodiment, a master mask is used as the photomask, but it can also be applied to a step-and-repeat redicle mask. In this case, photomask protection devices are bonded to both sides of the glass substrate.

〔Effect of the invention〕

As described above, according to the present invention, the support frame of the protective device is provided with a plurality of ventilation holes penetrating the inside and outside, thereby eliminating the difference in temperature and humidity between the inside and outside air, and preventing dew droplets from adhering to the transparent protective plate and distortion. This prevents the occurrence of the pattern and enables accurate pattern transfer.

[Brief explanation of drawings]

FIG. 1 is a vertical sectional view showing a conventional photomask protection device, FIG. 2 is a perspective view of the device shown in FIG. 1, and FIG. 3 is a photomask protection device according to an embodiment of the present invention. The vertical cross-sectional view 444 is a perspective view of the frame shown in FIG.
... Photomask, 6... Glass substrate, )... Thin film pattern, lO... Photomask protection device, 11
...Support frame, 12...Vent hole. Note that the same reference numerals in the figures indicate the same or equivalent parts. Agent Sakuo Oiwa Figure 1 Figure 2 Figure 3 Figure 4 Showa Year, Month, Day 1, Indication of the case Patent application 1984-: L321i! ! $39
2. Title of the invention: Protective device for photomasks for exposure 3. Relationship with the case of the person making the amendment Patent applicant address: 2-2-3 Marunouchi, Chiyoda-ku, Tokyo Name:
(601) Mitsubishi Electric Corporation Representative Hitoshi Katayama 4, Agent 6, "Detailed Description of the Invention" column of the specification to be amended. 6. Contents of amendment (1) "Small hole (to)" in the 14th line of page 4 of the specification is corrected to "small hole (6)." (2) Correct "Photomask" in the 12th line of page 5 of the specification to "Photomask". that's all

Claims (1)

[Claims] tll A support frame that is open at the top and bottom and has a plurality of small ventilation holes in the sides that penetrate inside and outside, and a transparent protection that is fixed to the top of the support frame and covers the openings. It is equipped with a board,
A protection device for a photomask for exposure, characterized in that the lower part of the support frame is applied and bonded to at least the outer periphery of the upper surface side of the photomask, which is patterned. (2) The protection device for a photomask for exposure according to claim 1, wherein the ventilation small hole is a tapered hole with a large outer side. (3) The protection device for an exposure photomask according to claim 1 or 2, wherein the ventilation holes are provided at an angle with the inner position higher than the outer position.