JPH04349461A - Photomask - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

[Detailed description of the invention]

0001

[Field of Industrial Application] The present invention relates to a photomask used in a photolithography process in the manufacture of thin film magnetic heads, semiconductor devices, etc., and in particular, the present invention relates to a photomask used in a photolithography process in the manufacture of thin film magnetic heads, semiconductor devices, etc. In particular, the present invention relates to a photomask that is easy to separate from the resist film surface after being closely exposed to the resist film surface. The present invention relates to the structure of a photomask.

Photolithography technology is now widely used as an indispensable technology when manufacturing thin film magnetic heads, semiconductor devices, and the like. When forming fine thin film patterns on a substrate with high precision using photolithography technology, a photomask pattern is created by exposing a resist film surface coated on a substrate on which a metal thin film, etc. has been formed, with a photomask in close contact with light. Contact exposure is preferable, in which a resist pattern is formed by transferring the photomask onto the resist surface. However, in such contact exposure, it becomes difficult to separate the photomask that is in close contact with the resist film after exposure, and when the photomask is removed, the resist film may be damaged. There was a tendency for peeling to occur. Therefore, there is a need for a photomask that can be easily separated from the resist film after contact exposure.

0003

[Prior Art] A conventional photomask has a pattern film constituting a transfer mask pattern in which a metal film made of Cr or the like or a metal oxide film is patterned into a predetermined pattern on one side of a mask substrate made of transparent glass. When using such a photomask to accurately pattern a metal thin film deposited on a substrate into a predetermined fine pattern in the manufacturing process of a thin-film magnetic head, for example, a resist is placed on the metal thin film. After applying a film and exposing the resist film with a photomask having the fine pattern film in close contact with the resist film to transfer a fine mask pattern to the resist surface, and developing this to form a resist pattern. A fine metal thin film pattern is formed on the substrate by etching the metal thin film portion exposed from the resist pattern and subsequently removing the resist pattern.

0004

[Problems to be Solved by the Invention] However, in the conventional contact exposure as described above, when the photomask that is in close contact with the resist film is separated after exposure, the resist film is damaged due to the adhesiveness of the resist film. There was a problem that it became more difficult to separate the photomask, and that the resist film peeled off when the photomask was removed.

[0005] In order to solve such problems,
As shown in FIG. 4(a), a metal film made of, for example, Cr or the like is coated on one surface of a mask substrate 12 made of transparent glass.
Alternatively, the entire surface of the photomask 11 provided with the pattern film 13 constituting the transfer mask pattern in which a metal oxide film is patterned into a predetermined pattern is coated with, for example, polyvinyl alcohol, which is difficult to adhere to the resist film and easily separates from the resist film. (PVA) etc. is spin coated,
A method was used in which the photomask 11 was exposed to light while being in close contact with the resist film 22 on the opposing processing substrate 21 via the PVA coat 14, as shown in FIG. 4(b).

However, the PVA coat 14, which is coated on the surface of the photomask 11 that is in close contact with the resist film, peels off during several exposure steps and loses its effect. mask 1
Since it is necessary to re-coat the entire surface of the photoreceptor 1 with PVA, there is a problem in that extra steps and time are required, and the overall working efficiency of the exposure process is deteriorated.

SUMMARY OF THE INVENTION In view of the above-mentioned conventional problems, an object of the present invention is to provide a novel photomask that can be easily separated from a resist film after contact exposure without peeling off the resist film. It is something.

[0008]

[Means for Solving the Problems] In order to achieve the above-mentioned object, the present invention provides a photomask comprising a pattern coating forming a transfer mask pattern on one side of a mask substrate, the photomask comprising: a pattern coating forming a transfer mask pattern; The structure is such that a polymeric material film having low adhesion to the resist film is formed on a region on the surface where the pattern film is provided, avoiding the pattern film.

[0009] Furthermore, the polymeric material film with low adhesion is
It is provided in the shape of a mark for alignment with the substrate on which the resist film is provided, and is configured to also serve as the mark for alignment.

0010

[Operation] In the present invention, on the area on the surface of the mask substrate on which the pattern coating constituting the transfer mask pattern is disposed, avoiding the pattern coating, a material having low adhesion to the resist film, such as polytetrafluoroethylene, is applied. (Product name: Teflon) or the like and has a thin film thickness of about 10 μm or less, and this polymer material film also serves as a gap layer with the resist film.

[0011] Then, with the photomask and the opposite substrate coated with a resist film being aligned and in close contact with each other, the resist film is exposed through the photomask, and then a photo is applied from above the resist film. By separating the mask, the photomask is brought into close contact with the resist film through the polymer material film with low adhesion, and since the adhesion area between the polymer material film and the resist film is also reduced, the resist film It becomes possible to easily separate it without peeling it off.

[0012] Furthermore, the polymeric material film with low adhesion is
For example, the four corners of a photomask are patterned and provided in the shape of alignment marks with a substrate provided with a resist film.
It can also be configured to serve as the positioning mark.

[0013]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Examples of the present invention will be described in detail below with reference to the drawings. FIGS. 1(a) and 1(b) are views showing one embodiment of a photomask according to the present invention, where FIG. 1(a) is a plan view and FIG. FIG.

In both of these figures, reference numeral 12 denotes a mask substrate made of transparent glass, and on one surface of the mask substrate 12, a metal film made of, for example, Cr or a metal oxide film thereof is coated for predetermined transfer purposes. A pattern film 13 formed on the mask pattern is coated with, for example, polytetrafluoroethylene (trade name: Teflon), which has low adhesion to the resist film, on the four corner areas, avoiding the pattern film 13, to form a pattern. A polymer material film 32 having a thickness of 5 to 10 μm is provided. Moreover, such a polymer material film 32
By making the film thickness uniform and controlling it to a predetermined thickness, it also serves as a gap layer between the resist film and the resist film.

Therefore, as shown in FIG. 2, a processing substrate 2 coated with such a photomask 31 and a resist film 22.
The photomask 3 is aligned by facing the photomask 3.
1 polymer material film 32 and the resist film 22 of the processing substrate 21
After exposing the resist film 22 through the photomask 31 in a state in which they are in close contact with each other, the photomask 31 is separated from the top of the resist film 22, so that the photomask 31 and the resist film 22 are in close contact with each other. Since the photomask 31 and the resist film 22 do not come into direct contact with each other through a polymeric material film with a low contact area and a reduced contact area, the photomask 31 and the resist film 22 can be bonded together without peeling off the resist film 22. It can be easily pulled apart.

Furthermore, FIGS. 3(a) and 3(b) are diagrams showing other embodiments of the photomask according to the present invention, and FIG.
is a plan view, and Figure (b) is a cross-sectional view of the main part taken along the line AA' shown in Figure (a).

The embodiment shown in this figure is shown in FIGS. 1(a) and 1(b).
) is different from the example in which the pattern coating 13 constituting the transfer mask pattern on the mask substrate 12 is disposed in an area that avoids the pattern coating 13, and in this example, the area where the pattern coating 13 forming the transfer mask pattern is disposed is separated from the processing substrate provided with the resist film. At the position where the alignment mark is provided, a film of 5 to 50% is made of a material that has low adhesion to the resist film, such as polytetrafluoroethylene (trade name: Teflon), etc.
A polymer material film with a thickness of 10 μm is patterned in the shape of an alignment mark as shown in the figure to facilitate separation after adhering to the resist film, and to form a gap layer between the resist film and the alignment mark. Polymer mark 41 that also serves as
The structure of the photomask is provided with the following.

The configuration of this embodiment also provides the same effects as the embodiments shown in FIGS. 1(a), 1(b) and 2. In addition to the polytetrafluoroethylene (trade name: Teflon) film, for example, a polyethylene film, a polyester film, etc. can also be used as the polymer material film with low adhesion to the resist film in the above embodiments. Effects can be obtained.

[0019]

As is clear from the above description, according to the photomask according to the present invention, separation from the resist film after contact exposure can be achieved extremely easily without peeling off the resist film. The practical effects are significant, such as improved yield in the exposure process and improved work efficiency.

[Brief explanation of drawings]

FIG. 1 is a diagram showing an example of a photomask according to the present invention.

FIG. 2 is a sectional view of a main part for explaining an exposure process using a photomask according to the present invention.

FIG. 3 is a diagram showing another example of the photomask according to the present invention.

FIG. 4 is a cross-sectional view of main parts for explaining a conventional photomask and an exposure process.

[Explanation of symbols]

12 Mask board 13 Pattern coating 21 Processed substrate 22 Resist film 31 Photomask 32 Polymer material membrane 41 Polymer mark

Claims (2)

[Claims] 1. A photomask comprising a pattern film (13) constituting a transfer mask pattern on one surface of a mask substrate (12), the photomask comprising: a mask substrate (12);
) A polymeric material film (32) having low adhesion to the resist film is formed on a region of the patterned film (13) on the surface of the patterned film (13) that avoids the patterned film (13). mask. 2. The polymer material film (41) with low adhesion
) is provided in the shape of an alignment mark with respect to the substrate provided with the resist film, and serves also as the alignment mark.