JP2000347382A - Resist mask and its formation - Google Patents

Abstract

PROBLEM TO BE SOLVED: To easily obtain a coating film having high uniformity and to manufacture a high precision mask by forming a resist film from plural resist layers and controlling the thickness of each of the resist layers. SOLUTION: A mask substrate 1 comprises quartz glass 2 and a light shielding film 3 laminated on the glass 2. A resist film 4 is formed on the mask substrate 1 by laminating 1st to 3rd resist layers 4a-4c. The resist film 4 is formed from the plural resist layers 4a-4c and the thickness of each of the resist layers 4a-4c is controlled. Since unevenness in the thickness of a resist film by a rotary cup system is caused in the drying of an applied resist and is in proportion to the thickness of a coating film, the unevenness can be reduced by dividedly applying the resist.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a pattern forming mask used in a semiconductor device manufacturing process and the like, and a method of forming the same. More specifically, the present invention relates to a method of applying a mask resist, and more particularly to a method of applying a mask resist that reduces variation in formation of a target resist film thickness in a rotary cup (closed type) mask resist application.

[0002]

2. Description of the Related Art Heretofore, there has been an open cup type or a rotary cup (closed type) type as a mask resist coating method. In the application of a resist by the open cup method, it is necessary to manufacture a wind-removing board based on experience in order to uniformly apply a square mask substrate in order to spread the resist in the circumferential direction and dry the resist.

[0003]

Further, in the resist coating by a rotary cup (closed type) method, a square mask substrate can be uniformly coated because no wind is generated at the time of coating, but the resist is dried. In this case, the upper lid of the rotary cup is opened, and the mask substrate is rotated and dried in the same manner as in the open cup method. In this drying, there is a problem that a uniform thickness of the resist layer is fluctuated, thereby causing a random thickness variation.

SUMMARY OF THE INVENTION The present invention has been made to solve the above-mentioned problems. In a mask resist coating method, the formation of a resist film thickness by a rotary cup (closed type) system or the like is divided into a plurality of coatings. It is another object of the present invention to provide a resist mask in which a resist film having a target film thickness is formed by reducing the variation in film thickness generated in drying the resist, and a method for forming the same.

[0005]

According to the present invention, there is provided a resist mask having a resist film formed by laminating a plurality of resist layers to a desired thickness.
In addition, the method for forming a resist mask of the present invention includes a step of applying a resist on a mask substrate and drying the same to form a resist layer having a predetermined thickness by a rotary cup (closed type) method or the like a plurality of times. A resist film having a desired laminated film thickness is formed. This makes it possible to obtain a resist mask having a desired thickness and a resist film whose thickness variation is controlled to be small.

[0006]

FIG. 1 is a sectional view showing a resist mask formed according to an embodiment of the present invention, and FIG. 2 is a view for explaining a method of forming the resist mask.
As shown in FIG. 1, the mask formed by the present invention includes a mask substrate 1 composed of quartz glass 2 and a light shielding film 3 laminated thereon. Also, the resist film 4
Is formed on the mask substrate 1, and is formed by laminating first to third resist layers 4a, 4b, 4c. This embodiment is characterized in that the resist film 4 is formed from a plurality of resist layers and that the thickness of each resist layer is controlled.

FIG. 2 is a sectional view showing a method of forming the resist mask along a process. Hereinafter, the resist layer 4
Is formed to a thickness of, for example, 300 nm. In FIG. 2, 11 is a rotary cup type chamber, 12 is its lid (lid), 1
Reference numeral 3 schematically shows a turntable on which the mask substrate 1 is placed and fixed or rotated. Figure 2 shows the mask manufacturing process.
(A) As shown in FIG.
A resist is applied on the resist substrate 1 so as to have a resist film thickness of m. In order to dry the applied resist, the upper lid 12 of the rotary cup is opened and rotational drying is performed to form the first resist layer 4a. When the coating rotation speed is the same, the thickness of the resist layer can be set to an arbitrary coating thickness depending on the coating rotation time. Therefore,
The coating film thickness is controlled by controlling the coating rotation time.

Next, as shown in FIG. 2B, a first resist layer 4a is formed on the first resist layer 4a by a rotary cup method to a thickness of 100 nm.
The resist is applied so that the resist film thickness becomes.
In order to dry the applied resist, the upper lid 12 of the rotary cup is opened and rotational drying is performed to form the second resist layer 4b. Thus, the resist layers 4a, 4
The layer thickness of b is set to 200 nm.

Finally, as shown in FIG. 2C, a 100 nm thick film is formed on the second resist layer 4b by a rotary cup method.
The resist is applied so that the resist film thickness becomes.
In order to dry the applied resist, the upper lid 12 of the rotary cup is opened and rotational drying is performed to form the third resist layer 4c. As described above, the resist layers 4a,
4b and 4c are laminated, and the integrated film thickness of the resist film 4 is 30
It is formed to a thickness of 0 nm.

[0010] The variation in the resist film thickness in the rotary cup method is caused when the applied resist is dried.
Further, the variation in the film thickness is proportional to the coating film thickness. Therefore, the application variation can be made smaller in the case where the resist film is applied three times and in the case where the resist film is applied in 100 nm each time than in the case where the resist film thickness of 300 nm is applied once. For example, in the case of a finished film thickness of 300 nm, a variation of 15 nm in one application can be reduced to 10 nm or less in three applications.

[0011]

The resist mask and the method of forming the same according to the present invention are constituted as described above. For example, the resist film formation can be divided into a plurality of times of resist coating and drying by a rotary cup (closed type) method. A coating film with good uniformity can be obtained by a simple method, which can contribute to the production of a high-precision mask.

[Brief description of the drawings]

FIG. 1 is a cross-sectional view showing a resist mask of the present invention.

FIG. 2 is a sectional view showing a method of forming a resist mask according to the present invention along steps.

[Explanation of symbols]

1 mask substrate, 2 quartz glass, 3 light shielding film, 4 resist film, 4a, 4b, 4c resist layer.

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[Procedure amendment]

[Submission date] March 27, 2000 (2003.
7)

[Procedure amendment 1]

[Document name to be amended] Statement

[Correction target item name] Claims

[Correction method] Change

[Correction contents]

[Claims]

Claims (3)

[Claims] 1. A resist mask comprising a plurality of resist layers laminated and provided with a resist film having a desired laminated film thickness. 2. The method according to claim 1, wherein the step of applying a resist on the mask substrate and drying it to form a resist layer having a predetermined thickness is repeated a plurality of times to form a resist film having a desired thickness. Method of forming a resist mask. 3. The method for forming a resist mask according to claim 2, wherein the application and drying of the resist are performed by a rotary cup (closed type) method.