JPS5835537A - Production for pattern mask - Google Patents

Abstract

PURPOSE:To obtain a pattern mask having less pattern defects due to pinholes, by forming the first resist pattern and the second resist pattern having the same form as the first resist pattern in piles on a mask film. CONSTITUTION:The first resist pattern 3a for forming a semiconductor chip is formed on the surface of a mask film 2 which is formed on the main face of a mask substrate 1. A photoresist film 13 is formed on the first resist pattern 3a, and a pattern having the same form as the first resist pattern 3a is described and exposed and developed to form the second resist pattern 13a. Next, a pattern mask is produced in the step where parts of the mask film 2 where resist patterns 3a and 13a are not formed are etched selectively. Thus, since there is little probability that a pinhole is generated in the same position of first and second resist patterns 3a and 13a, the pattern mask where pattern defects due to pinholes are lessened considerably is obtained.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention provides a semiconductor integrated circuit device (
The following is an example of a pattern mask used when manufacturing an IC chip. Nitoshi explains.

-10 In order to improve the manufacturing yield of chips, it is necessary to
It is necessary to reduce defects in chip patterns. In particular, defects in the pattern of the pattern mask used for pattern transfer during the manufacture of 1-process C chips can occur on all semiconductor wafers (hereinafter referred to as wafers/-t
Therefore, reducing defects in the pattern of this pattern mask has a great effect on improving the manufacturing yield of IC chips.

The pattern mask includes a full-size pattern mask that has the same pattern as the IC chip pattern (hereinafter referred to as the "full-size pattern") and performs pattern transfer by exposing the full-size pattern to the wafer, and a full-size pattern mask that has the same pattern as the IC chip pattern (hereinafter referred to as the "full-size pattern"), and a full-size pattern mask that transfers the pattern by exposing the wafer to the full-size pattern. There is an enlarged pattern mask (hereinafter referred to as a "reticle") which has a pattern enlarged by 1O times and performs pattern transfer by exposing the enlarged pattern to a wafer in a reduced size.

Recently, he used a reticle in which enlarged patterns of several IC chips were formed adjacent to each other in the row and column directions, reduced the enlarged patterns of this reticle to a full-size pattern, and transferred this full-size pattern to a wafer. A method is now used in which the wafer is exposed while being moved in the row direction and the column direction to transfer a high-resolution pattern. However, even in this case, the enlarged pattern of the reticle needs to be defect-free.

'Next, an example of a conventional reticle manufacturing method will be described with reference to FIGS. 1 to 3 showing the main stages thereof.

First, as the jlE1 stage, the plan view shown in FIG. 1 (A) K and the plan view shown in FIG. 1 (B) Ic (IB-
As shown in the cross-sectional view taken along line IB, a mask film (2) such as a chrome film is formed on the main surface of a mask substrate (1) made of a transparent plate-like material such as glass, and then this mask film (
After forming a photoresist film (3) on the surface of the photoresist film (3), the photoresist film (3) is subjected to a baking process. As shown in Figure 2 (B), which is a cross-sectional view taken along the [B-■B line of Shu], using an optical means such as a 1-pattern generator, Draw an enlarged chip pattern for forming 4 chips in adjacent 2 rows and 2 columns and turn off the light.

Fiducial marks for alignment to be used when using a reticle are drawn at the center of the edges along opposite sides of the surface of the photoresist film (3) and are made dark. Next, the exposed photoresist film (3) Ic
A development process is performed to remove the unexposed portions of the photoresist film (3) from the surface of the mask film (2), and an enlarged chip resist pattern (3a) is formed on the surface of the mask film (2).
and a fiducial resist mark (sb) is left and a baking process is performed as the third step.
As shown in the plan view of the figure, 1 enlarged chigage resist pattern (3a) and fiducial resist mark (3b)
) The selective etching process used for the T-etching mask was applied to the mask film (2) to form a 1-enlarged chip pattern (3a) and an IT-7' (regist mark) on the surface of the mask substrate (1). 3b), a mask film for forming an enlarged chip pattern (2
a) and the fiducial mark forming phase masked M(
2b) ◇Next, the enlarged chip resist pattern (3a) and fiducial resist mark (3b) are removed from each surface of the mask coating (2a) and the mask coating (2b), and the mask substrate (1) is removed. By applying a baking treatment to the reticle, a reticle according to this conventional method is obtained.

By the way, in this conventional method, 11 shown in FIG.
In the second stage, even if the current best technology is used, the enlarged chip resist pattern (3a ) will have several pinholes, so
Due to these pinholes, a mask film (2a) for forming an enlarged chip pattern that accommodates the defects is formed on the surface of the mask substrate (1) in step #I3 shown in FIG. 3, so a reticle with a defect-free pattern is produced. I couldn't. Therefore, in order to produce a reticle with a defect-free pattern, after completing the third step shown in FIG.
It must be corrected by some method, such as by depositing a metal film. However, repairing defects caused by such pinholes takes a lot of time and effort, and as the dimensions of each pattern become minute, the repair yield for defects caused by pinholes decreases. there were.

This invention has been made in view of the above-mentioned problems, and includes forming a first resist pattern for forming a conductor chip on the surface of a mask film formed on the main surface 1 of a mask substrate, and further A method of manufacturing a pattern mask with extremely few pattern defects due to pinholes by forming a second resist pattern having the same shape as the first resist pattern on the first resist pattern. The purpose is to provide.

Hereinafter, a method for manufacturing a reticle according to an embodiment of this invention will be described. 1 to 7 will be explained.

First, as a first step, a film is formed on the main surface as shown in FIG. 2 through the same steps as the first and second steps of the conventional example shown in FIGS. A mask substrate (1) is prepared in which a first enlarged chip resist pattern y (3a) and a first fiducial resist mark (3b) are formed on the surface of the mask film (2). As a second step, another mask substrate (1) in the same state as the mask substrate (1) in this state is produced, and using this another mask substrate (1), the third conventional example shown in FIG.
After the step is completed, a conventional reticle is manufactured, and a reticle original with an inverted pattern (later shown as Kaυ in FIG. 5) is manufactured using this conventional reticle as a mask. Next, as the third step, a reticle original with an inverted pattern is manufactured as shown in FIG. In Figure 2 A, [[B-I
The first enlarged chip resist pattern (3a) and the first fiducial resist mark (sb) (not shown in FIG. 4) are aligned as shown in the WT surface view along the line corresponding to the IB line. A photoresist film 01 sensitive to light in the ultraviolet region is formed on the surface of the mask film (2).

Next, as the fourth stage, as shown in the perspective view of Figure 5,
The reticle original plate Qυ of the inversion/< turn obtained in the second step above [FIG. 5 shows the fiducial mark (2
1a) is superimposed on the photoresist MlfII shown in the sectional view of FIG. 4 with a slight gap between the photoresist film H and the photoresist film H. Next, the photoresist film 01 is passed through the reticle original plate (2) using a mask transfer device that is composed of an objective lens (0η), a reflector (reflector), a cn (cn), and an eyepiece (to) and has the same function as the aligner for way I. is irradiated with light in the visible region, which has a longer wavelength than the wavelength of light in the ultraviolet region, and a mask coating (2) of this light is applied.
While observing the light reflected by K, the reticle master is slightly moved in the direction of the arrows X, Y, and 0 in the figure to form the Jll fiducial resist mark (3b) on the surface of the mask coating (2). 7 alignments are performed between the fiducial plate (21a) of the reticle original plate υ, and then, when the photoresist film 03 is irradiated with light in the ultraviolet region through the reticle original plate (b), the mask film (2) is a first enlarged chip resist pattern (3a) (not shown) formed on the surface and a photoresist film on the first fiducial resist mark (ab); A portion having the same shape as the fiducial registration mark (3b) is exposed.

Next, as the fifth step, in Figure 6, [[B] of Figure 2 (A)
-IIBI! As shown in the cross-sectional view along the line corresponding to 1, this exposed photoresist film (13) is developed and the unexposed portion of this photoresist film (1 frame) is exposed from the surface of the mask film (2). A second enlarged chip resist pattern (13a) and a second fiducial resist pattern (13a) and a second fiducial resist mark (3b) (not shown in FIG. fiducial registration mark (not shown)
Leave them on top of each other and perform the baking process.

Next, as the 6th stage of tlE, as shown in the plan view of FIG. A first enlarged chip resist pattern (3
a) and the first, fiducial registration mark (
sb) as an etching mask is applied to the mask coating (2)K, thereby forming a first enlarged chip resist pattern (3a) and a first fiducial mark (1) on the surface of the mask substrate (1). 3b), a mask film for forming an enlarged chip pattern (
2a) and the mask coating (2b) for forming fiducial marks are left. Then, these mask coatings (2a) are left.
and (2b), the second enlarged chip resist pattern (13a) and! The first enlarged chip resist pattern y (3a) and the fiducial resist mark (3b) in which 42 fiducial resist marks are superimposed are removed, and the mask substrate (1
) A reticle according to the method of this example is obtained by performing K baking treatment.

In the method of this embodiment, it is extremely rare that the position of the pinhole formed in the agi enlarged chip resist pattern (3a) coincides with the position of the pinhole formed in the second enlarged chip resist pattern (13a). So, the second
The first enlarged chip resist pattern fi-7 (3a) on which the enlarged chip resist pattern (13a) of
Fi is applied to the enlarged chip pattern forming mask film (2a) formed by selective etching used as an etching mask.
It is possible to obtain a reticle that has almost no pinholes and has extremely few pattern defects due to pinholes.

In this example, the first enlarged chimpress cyst pattern (
3a) Upper KJ2 enlarged chip resist pattern (13a
) 11111 on the first enlarged chip resist pattern (3a)
Although the method of transferring the pattern of the reticle original plate Qυ to 1 was used, it is not necessarily limited to this transfer method;
Even if a method of drawing and exposing the second enlarged chip resist pattern (13a) on the 7-photoresist film 01 using an optical means such as a pattern generator using the Wtl fiducial resist mark (3b) as a reference is used, this embodiment A similar effect can be seen.

Although the method for manufacturing a reticle has been described as an example, the present invention is not limited to this, and can also be applied to a method for manufacturing a full-size pattern mask. In the manufacturing method, a first resist pattern for forming a semiconductor chip is formed on the surface of a mask film formed on the main surface of a mask substrate, and further, on this first resist pattern,
Since a second resist pattern having the same shape as the first resist pattern is formed by overlapping, the positions of pinholes formed in the first resist pattern and the positions of pinholes formed in the second resist pattern are formed. It is extremely rare for the two to match. Therefore, the mask film for semiconductor chip formation formed by subjecting the mask film to a selective etching process using the first resist pattern overlaid with the second resist pattern as an etching mask has almost no pins. It is possible to obtain a pattern masker without holes and with extremely few pattern defects due to pinholes.

[Brief explanation of the drawing]

Figure 1 (Shu is the first example of a conventional reticle manufacturing method)
A plan view showing the state of the stage, Fig. 1 CB) is shown in Fig. 1 (A).
Figure 2 (A) is a plan view showing the state of the second stage of the conventional example, Figure 2 ((9) is a cross-sectional view taken along line B-IB of
Cross-sectional view at II B-II B Im in Figure (A), 3rd
4 is a plan view showing the third stage state of the conventional example, and FIG. 4 is a plan view showing the second stage state of an embodiment of the present invention.
5 is a perspective view showing the state of the fourth stage of the above embodiment, and FIG. 6 is a sectional view taken along the line corresponding to the [B-[IB line of A). Figure 2 ((transformation) ■
A sectional view taken along a line corresponding to the B-11B line, FIG. 7, is a cross-sectional view of the above embodiment! In the figure, (1) is a mask substrate, (2) is a mask coating, (2a) is a mask coating for forming an enlarged chip pattern (a mask coating for forming a conductor chip), (ji!kl) is the mask film for forming a fiducial mark, ('') is the first enlarged chip resist pattern (first resist pattern)
, (3b) u fiducial registration mark, -
is a photoresist film, (13a) ki is a second enlarged chip resist pattern (second resist pattern). Note that the same reference numerals in the figures indicate the same or corresponding parts. Agent Makoto Kuzuno - (1 other person) Figure 1 Figure 2 199- Figure 3 Figure 4 Figure 5 Figure 6 Figure 7 Procedural amendment (voluntary) Showa SQ, -II May 5th Commissioner of the Patent Office Hall 1, Incident (7) Display Special Application 1986-1! $5
1ag No. 9 2, Title of the invention Pattern mask creation method 3, Person making the amendment 200-5 Claims column 6 of the specification to be amended Contents of the amendment (1) Complete the claims of the specification Correct as shown in the attached sheet. F. A document showing the scope of claims after the list of attached documents has been corrected. One or more copies of the scope of claims. The first step is to form a resist pattern and a fiducial resist mark.
step W & 2 of arranging several photoresist patterns on the surface of the mask pattern covering the first resist pattern and the fiducial resist mark; 1
a third step of transferring or drawing exposing a pattern having the same shape as the first resist pattern onto the photoresist pattern on the resist pattern using optical means;
The transferred or drawn exposed photoresist pattern is subjected to a developing process to remove the unexposed portions of the photoresist pattern, leaving the second resist pattern on the first resist pattern and performing a baking process. a fourth step, performing a selective etching process on the mask pattern using the first resist pattern on which the second resist pattern is superimposed and the fiducial resist mark as an etching mask; The portion of the mask pattern that is not overlapped by the resist pattern and the fiducial resist mark is removed from the surface of the mask substrate, and the first resist pattern and the fiducial resist mark are removed. A semiconductor chip forming layer mask pattern corresponding to the first resist pattern and a fiducial mark corresponding to the fiducial resist mark are formed on a portion of the surface of the mask substrate directly below the essential resist mark, respectively. a fifth step of leaving a phase mask pattern, and the first step in which the second resist pattern is superimposed on the surfaces of the semiconductor chip forming layer mask pattern and the fiducial mark forming phase mask pattern, respectively.
A method for producing a patterned mask comprising a sixth step of removing the resist pattern and the fiducial resist mark and performing baking treatment 0-/

Claims (1)

[Claims] (1) Forming a first resist pattern and fiducial resist marks for semiconductor chip formation on the surface of a mask film formed on the main surface of a mask substrate.
a second step of forming a photoresist film on the surface of the mask film covering the first resist pattern and the fiducial resist mark; 1st
a third step of transferring or drawing exposure to the photoresist film using an optical means a pattern having the same shape as the first resist pattern;
The transferred or drawing-exposed photoresist film is developed to remove the unexposed portion of the photoresist film, and the second resist pattern is left on the first resist pattern and then subjected to baking treatment. Step 4, performing a selective etching process on the mask film using the first resist pattern overlaid with the second resist pattern and the fiducial resist mark as an etching mask to form the first resist pattern. The portion of the mask coating that is not covered by the first resist pattern and the fiducial resist mark is removed from the surface of the mask substrate, and the surface of the mask substrate immediately below the first resist pattern and the fiducial resist mark is removed. a fifth step of leaving a mask film for forming a semiconductor chip corresponding to the first resist pattern and a mask film for forming a fiducial mark corresponding to the fiducial registration mark on the upper part, and the semiconductor chip; Forming mask film and said fiducial-r −/Register J of said GL on which said second resist pattern is superimposed on the surface of said forming mask film respectively) Pattern oyohi said fiducial resist mark is removed and baked A method for manufacturing a patterned mask, comprising a sixth step of performing processing.