JPH0395554A - Reticle - Google Patents

Abstract

PURPOSE:To correct the strain of a transparent substrate by providing a pattern for correction on the opposite surface of a transparent substrate from a surface where a pattern part for semiconductor device exposure is formed. CONSTITUTION:The exposure pattern part 2 to be projected when a semiconductor device is formed on one surface of the transparent substrate 1 and the pattern 4 for correction is formed on the other surface without interfering with the pattern part 2. The pattern 4 is formed simultaneously with a metallic film which forms the pattern part 2 to absorb the deformation of the substrate 1 due to the contraction of the metallic film forming the pattern part 2 and the shape and thickness are so determined that the substrate 1 is almost flat. Consequently, there is no deviation in focusing between the center part and peripheral part at the time of exposure, the strain of the substrate due to the contraction of the metallic film is corrected, and the accurate pattern is formed.

Description

[Detailed Description of the Invention] [Summary] For the purpose of correcting distortion of the substrate and improving accuracy with respect to reticles used in the manufacture of semiconductor devices, the present invention includes a transparent substrate and a film formed on the surface of the transparent substrate. In a reticle having a semiconductor device exposure pattern formed by etching a metal film, a correction pattern is provided in an area other than the area facing the semiconductor device exposure pattern on the back surface of the transparent substrate, and It is designed to correct distortion of the transparent substrate due to shrinkage.

[Industrial application field]

The present invention relates to a reticle used during the manufacture of semiconductor devices, and more particularly to a method for improving the accuracy thereof.

In recent years, with the improvement in the degree of integration of semiconductor devices,
Strict alignment of pattern shapes in the IJ lithography process is required. For this reason, there are demands to improve the positional accuracy of exposure apparatuses, and there is also a need to further improve the accuracy of the reticle, which corresponds to the original plate of the semiconductor device used in this case.

[Conventional technology]

FIG. 2 shows a conventional reticle. This is 2ml thick
A thin film of Cr(1)(2) is formed on one side of a transparent substrate l made of glass or the like, and a semiconductor device exposure pattern 2 is formed from the Cr film by photoetching.

[Problem to be solved by the invention]

In the conventional reticle described above, when a thin Cr film is formed on one side of the glass substrate 1 by vapor deposition, etc., it is heated and formed at a high temperature. The shrinkage is greater, and the Cr film 3 side is deformed to become concave as shown in FIG. If there is such deformation (warpage), there will be a difference in the imaging distance between the peripheral part and the central part during exposure when the semiconductor device exposure pattern 2 is formed by the photoetching method. , some parts are out of focus, resulting in poor pattern accuracy. Conventionally, this has been countered by increasing the thickness of the glass substrate 1 to increase its rigidity and reduce deformation.

However, although this method provides good pattern accuracy, there is a problem in that the thickness of the substrate deviates from the dimensions of a normal reticle, resulting in increased costs such as changes in the reticle itself, processing holder, and process.

In view of the above conventional problems, it is an object of the present invention to provide a reticle that can maintain pattern accuracy without changing the thickness of the substrate.

[Means to solve the problem]

In order to achieve the above object, the reticle of the present invention has a transparent substrate 1 and a semiconductor device exposure pattern portion 2 formed by etching a metal film formed on the surface of the transparent substrate 1. A correction pattern 4 is provided in a region other than the region facing the semiconductor device exposure pattern section 2 on the back surface of the transparent substrate 1 to correct distortion of the transparent substrate 1 due to contraction of the metal film.

[For production]

A transparent substrate 1 made of a metal film for forming a pattern part for semiconductor device exposure (3) and (4) by providing a correction pattern 2 on the opposite side of the transparent substrate 1 to the surface on which the pattern part for semiconductor device exposure is formed. The deformation of the pattern is corrected, and the exposure when forming a pattern for exposure of a semiconductor device is brought into precise focus, making it possible to form an accurate pattern.

〔Example〕

FIG. 1 is a diagram showing a reticle in which the method of the present invention has been implemented, in which (a) is a perspective view, and (b) is a view taken along the Z arrow in FIG.

In this embodiment, an exposure pattern section 2 for projecting a semiconductor device shape is formed on one surface of a transparent substrate 1, and a correction pattern 4 interferes with the semiconductor device exposure pattern section 2 on the other surface. It is pretending not to do so. This correction pattern 4 is formed at the same time as the metal film forming the semiconductor device exposure pattern section 2. Also, this correction pattern 4
The shape and thickness of the transparent substrate 1 are such that deformation of the transparent substrate due to contraction of the metal film forming the semiconductor device exposure pattern portion 2 is canceled out, and the transparent substrate 1 becomes substantially flat. The semiconductor device exposure pattern section 2 is formed by resist coating, exposure, and
Although it is formed through various steps of development and etching, since the transparent substrate 1 is in a substantially flat state, there is no out-of-focus between the center and the periphery during exposure, and an accurate pattern is formed.

According to this embodiment, an accurate pattern can be formed without deforming the substrate even if a substrate having the same thickness as the conventional one is used. Therefore, it is possible to use a substrate with the same thickness as in the past, so there is no need to change the processing holder of the exposure machine.

〔Effect of the invention〕

As explained above, according to the present invention, by providing a correction pattern on a transparent substrate, deformation of the transparent substrate can be prevented, thereby making it possible to provide a reticle with an accurate pattern, which can be used in semiconductor device manufacturing equipment. This greatly contributes to improving the performance of

[Brief explanation of drawings]

FIG. 1 is a diagram showing an embodiment of the present invention, Figure 2 shows a conventional reticle; Figure 3 explains the problem that the invention seeks to solve (5) (6) This is a diagram for understanding. In the figure, 1 is a transparent substrate, 2 is a semiconductor device exposure pattern section; 4 is a correction pattern shows.

Claims (1)

[Claims] 1. A reticle having a transparent substrate (1) and a semiconductor device exposure pattern portion (2) formed by etching a metal film formed on the surface of the transparent substrate (1), comprising: A correction pattern (4) is provided in an area other than the area facing the semiconductor device exposure pattern section (2) on the back surface of the transparent substrate (1) to correct distortion of the transparent substrate (1) due to contraction of the metal film. A reticle characterized by: