JPS6022352Y2 - Mask to prevent overcrowding - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an improvement in a mask in exposure processing, particularly in contact exposure in which exposure is performed by bringing the mask into close contact with the resist-coated surface of a substrate to be processed.

This contact exposure is used to create extremely precise and fine patterns for semiconductor integrated circuits and the like.

However, if there is a gap between the mask and the substrate to be processed, the exposure pattern becomes blurred, which causes a fatal defect in devices that require microfabrication, such as semiconductor devices.

Therefore, in order to improve the adhesion between the mask and the substrate to be processed, in addition to applying mechanical pressure, vacuum suction is applied to the gap between the two in order to ensure complete completion.

As a result, the mask and the substrate to be processed come into close contact with each other, and after exposure,
The two cannot be peeled off properly, and the resist coated on the substrate to be processed is peeled off, which is a major cause of pinholes.

It is currently used in mass production systems as long as the defect rate of products (semiconductor products) is not significantly reduced if these pinholes occur locally or in small numbers.

However, although it goes without saying that mass productivity can be improved by reducing the number of pinholes, the problem still remains due to the large number of pinholes, despite measures being taken to prevent over-adhesion.

The present invention has improved such drawbacks, and has proposed a mask for preventing over-contact exposure, which includes a through-hole outside the pattern forming area and a sealing plate for sealing the through-hole.

Hereinafter, the present invention will be described in more detail with reference to the drawings.

FIG. 1 shows a cross-sectional view of a mask and a substrate to be processed in a conventional example, and 7 is a substrate for a working mask which is a substrate to be processed. It is more hollow.

8 is a master mask, which includes glass plate 6, pattern 5,
It consists of a protective resin 4 such as epoxy resin.

This protective resin 4 is applied onto the glass plate 6 from above the pattern 5 by spinner coating, and a large number of grooves 13 are formed in a thin shape toward the outside of the mask.

When the master mask 3 and the working mask 7 are separated after exposure, this groove 13 serves as an air passage, making it easy to separate the two.

However, even with this, over-adhesion occurs, and this protective resin 4
The resist 3 adheres to the protective resin 4 at the peak 14 of the hole 1.
0 opens.

And unexposed area 9 of resist 3 (portion indicated by hatch)
When the holes 10 are opened, holes are also opened in the metal film 2 which is to become a pattern during etching, resulting in so-called pinholes.

Therefore, the present invention prevents such adhesion,
An embodiment is shown in FIGS. 2 and 3, with FIG. 2 showing a perspective view of the master mask 3, and FIG. 3 showing a sectional view of the mask and the substrate to be processed.

In the figure, the same symbols as in FIG. 1 indicate the same contents, 51 indicates a pattern forming area, and 12 indicates a pattern forming area 5.
A through hole 11 is provided outside the master mask 8 and penetrates through the glass plate 6, and 11 is a sealing plate for the through hole 12 with sellotape or the like.These are provided in the master mask 8.

The master mask 8 and the substrate 7 to be processed are superimposed,
Contact exposure is performed using vacuum suction.

After exposure, by peeling off the sealing plate 11, air flows between the master mask 8 and the substrate 7 to be processed through the through hole 12, and the excessive contact between them is removed.

Therefore, even if the master mask 8 is removed, the target substrate 7
No resist peeling occurs, and no pinholes occur.

Experiments have shown that by simply providing a through hole 12 with a diameter of about 1 mm, the separation work between the mask and the substrate to be processed can be shortened, and the number of pinholes has been improved many times over the conventional method.

In addition, conventional methods require difficult work and equipment such as spinner coating of protective resin, but by applying the present invention, such coating means are no longer necessary.
There will be significant improvements both in terms of work and equipment.

[Brief explanation of the drawing]

FIG. 1 shows a conventional example, and FIGS. 2 and 3 show an embodiment of the present invention, in which 7 is a substrate to be processed, 8 is a mask, 11 is a sealing plate, 1
Reference numeral 2 indicates a through hole, and reference numeral 51 indicates a pattern forming area.

Claims (1)

[Scope of utility model registration request] A mask for preventing over-contact exposure, which includes a through-hole outside a pattern forming area and a sealing plate for sealing the through-hole.