JPS62265723A - Exposing method for resist - Google Patents

Abstract

PURPOSE:To shorten the time of exposing a resist and to reduce the probability of causing a displacement of the resist by forming a blanking part having no pattern at the same position as a nonexposure part on a mask for 1:1 type exposure unit, and roughly adjusting an alignment with the blanking part as a target. CONSTITUTION:A pattern 14 is formed corresponding to a pattern 8 transferred by a contraction projection exposure unit on a photomask 12 used in a 1:1 type exposure unit for transferring a pattern to other photoresist on a wafer 6. A blanking part 16 having no pattern is formed at a position corresponding to a part 10 having no pattern by a nonexposure part on the wafer 6 in the mask 12. When exposing by using the mask 12, the part 16 of the mask 12 is aligned to the part 10 having no pattern on the wafer 6 to be roughly adjusted in alignment.

Description

DETAILED DESCRIPTION OF THE INVENTION (Technical Field) The present invention relates to a method for exposing a resist layer used in photolithography (photoengraving) technology in the manufacturing process of semiconductor integrated circuit devices and the like.

(Prior Art) When fabricating a semiconductor integrated circuit device or the like, it is necessary to pattern a thin film on a semiconductor substrate (hereinafter referred to as a wafer) by etching.

Etching is performed by first forming a resist layer on a target thin film, exposing it to light through a photomask, and developing it to form a resist pattern.

Methods for exposing the resist layer include 1:1 type exposure, in which a photomask pattern is exposed with the same size, and reduction projection exposure, in which the photomask pattern is reduced to 1/10 or 115 times. In the case of reduction projection exposure, the photomask is specifically called a reticle. Reduction projection exposure is particularly advantageous for forming fine patterns.

Normally, the steps of resist coating, exposure, development, and ninoting are repeated multiple times for one wafer. During exposure, alignment is performed to prevent patterns from shifting. For alignment, an alignment pattern is provided in the pattern of the mask, and alignment is performed using the alignment pattern as a target.

However, it takes time and is not efficient to suddenly perform alignment for wl adjustment using an alignment pattern. Therefore, it is efficient to make some kind of rough adjustment for alignment.

(Objective) The present invention uses a reduction projection exposure apparatus to
After repeatedly exposing and developing a resist layer on a substrate to form a pattern, when exposing other resist layers formed on the same substrate using a 1:1 type exposure device, it is necessary to The purpose is to enable coarse adjustment.

(Structure) In the resist exposure method of the present invention, when performing step-and-repeat exposure using a reduction projection exposure apparatus, a non-exposed area is created in a part of the substrate.

In the mask for the 1:1 type exposure device, a blank area without a pattern is made in the same area as the non-exposed area, and the 1:1 type exposure device is
When performing alignment with a mold exposure device, coarse alignment adjustment is performed using the resist pattern of the non-exposed portion and the blank portion of the mask as g-marks.

Examples will be specifically described below.

FIG. 1 shows a reticle used in a reduction projection exposure apparatus.

A plurality of (four in this case) patterns 4 (4-1 to 4-4) are formed on this reticle 2. Using this reticle 2, a reduction projection exposure apparatus exposes the photoresist on the wafer 6 as shown in FIG. Four patterns are repeatedly transferred onto the photoresist on the wafer 6 at the same time by a step-and-repeat method. The transferred resist pattern 8 is a reduced pattern of the pattern 4 of the reticle 2.

Reference numeral 10 indicates a non-exposed portion provided between the patterns 8.

3 is a photomask used in a 1:1 type exposure apparatus for transferring a pattern to another photoresist on the wafer 6. In FIG.

A pattern 14 is formed on the photomask 12 in correspondence with the pattern 8 transferred by the reduction projection exposure device. In the photomask 12, a blank portion 16 without a pattern is provided at a position corresponding to a portion 10 without a pattern due to an unexposed portion on the wafer 6.

When performing exposure using the photomask 12, the blank portion 16 of the photomask 12 is aligned with the pattern-free portion 10 on the wafer 6, and rough alignment adjustment is performed.

(Effects) In the present invention, when performing step-and-repeat exposure using a reduction projection exposure system, a non-exposed area is created in a part of the substrate, and a mask for type 1 exposure equipment is provided with a mask that is identical to the non-exposed area. Create a blank area without a pattern, and
:When aligning with the L-type exposure device, the blank area is used as the target for coarse alignment adjustment, so 1.
: The time required for rough alignment adjustment using the 1-type exposure device is shortened, and the probability of misalignment occurring is also reduced.

[Brief explanation of drawings]

Fig. 1 is a plan view showing a reticle used in a reduction projection exposure system, Fig. 2 is a plan view showing a pattern transferred onto a wafer, and Fig. 3 is a plan view showing a photomask used in a 1:1 exposure system. It is. 2... Reticle, 6... Wafer, 10... Portion without pattern due to non-exposure. 12...Photomask, 16...Blank area without pattern.

Claims (1)

[Claims] (1) After exposing and developing the resist layer on the substrate by step-and-repeat using a reduction projection exposure device and forming a pattern, other resist layers formed on the same substrate are exposed to 1:1 type exposure. In the exposure method using a reduction projection exposure device, a non-exposed area is created in a part of the substrate, and a mask for a 1:1 type exposure device is provided with a non-exposed area in the same area as the non-exposed area. A blank area without a pattern is prepared in advance, and when alignment is performed using a 1:1 type exposure device, coarse alignment adjustment is performed using the resist pattern of the non-exposed area and the blank area of the mask as targets. resist exposure method.