JPH05165198A - Production of x-ray mask - Google Patents

Abstract

PURPOSE:To enable the etching of the thin films of a membrane material so as to simplify the process by utilizing a supporting frame as a mask and to simplify process by joining a wafer to the supporting frame before etching the thin films of the membrane material. CONSTITUTION:The thin films 2a of the membrane material are formed by a chemical vapor deposition method on both surfaces of the silicon wafer 1. The wafer 1 is then joined to the supporting frame 4. The thin film 2a of the back surface is dry etched with the supporting frame 4 as a mask to form the membrane 2. The wafer 1 is thereafter subjected to back etching and finally circuit patterns 3 are formed on the membrane 2. The joining of the supporting frame is executed before the back etching of the wafer 1 and the etching of the thin films 2a. Since the supporting frame 4 is utilized as the mask, the need for special masking for the back etching of the wafer 1 and the etching of the thin films 2a is eliminated.

Description

Detailed Description of the Invention

[0001]

[Field of Industrial Application] The inventions of claims 1 and 2 are
For example, the present invention relates to a method of manufacturing an X-ray mask used for X-ray lithography.

[0002]

2. Description of the Related Art FIG. 7 is a sectional view of an example of a conventional X-ray mask. The X-ray mask has a structure in which a circuit pattern 3 of an X-ray absorber made of a heavy element is formed on a membrane (thin film substrate) 2 made of a light element and having a thickness of several μm. Usually, an X-ray mask is made on a silicon wafer 1, and this silicon wafer 1 has a supporting frame 4 made of glass or ceramic.
Is joined to.

As a conventional method for manufacturing such an X-ray mask, various methods have been proposed which differ in the materials used, the order of processes, the method of forming the circuit pattern 3, and the like.

FIG. 8 shows, for example, the document "JJAP series 3,"
Proceedings of 1989 Int. Symp. On Micr
oProcessConference) ”, an example of a conventional method for manufacturing an X-ray mask shown in pages 99 to 103 (a) to (f).
FIG. 7 is a cross-sectional view showing the order of steps.

First, as shown in (a), a part of the back surface of the membrane material thin film formed on both surfaces of the silicon wafer 1 is removed by dry etching to form the membrane 2. Next, as shown in (b), the silicon wafer 1 is bonded to the support frame 4. Then, as shown in (c), wet etching, that is, back etching is performed from the back surface of the silicon wafer 1. Then, as shown in (d), the membrane 2 is formed by a sputtering method or the like.
An X-ray absorber film 3a is formed thereon, and a resist pattern 5 as shown in (e) is formed thereon. Finally, as shown in (f), the X-ray absorber film 3a is etched using the resist pattern 5 as a mask to form the circuit pattern 3 as shown in (f).

FIG. 9 shows, for example, the document “Monthly Semiconductor”.
Another example of the conventional method for manufacturing an X-ray mask shown in pages 107-111 of "World 1991.5" (a)-
It is sectional drawing shown in the process order of (e). In the figure, 6 is a silicon dioxide film which serves as a mask for etching the X-ray absorber film 3a. In this example, the order of steps of pattern formation, back etching, and bonding is the reverse of the method shown in FIG.

[0007]

DISCLOSURE OF THE INVENTION Problems to be Solved by the Invention
In any of the exemplified methods in the method of manufacturing the line mask, the membrane material thin film formed on the silicon wafer 1 is separately etched before the back etching of the silicon wafer 1. In the etching process, masking is performed by a photolithography process, or simply because the silicon wafer 1 is covered with a mask such as glass, there is a problem that it takes time.

The inventions of claims 1 and 2 are intended to solve the above problems, and an X-ray mask can be manufactured more easily.
An object is to obtain a method for manufacturing a line mask.

[0009]

X according to the invention of claim 1
In the method for manufacturing a line mask, after bonding a wafer having a membrane material thin film formed on both surfaces to a support frame, the membrane material thin film is etched using the support frame as a mask.

In the method of manufacturing an X-ray mask according to a second aspect of the present invention, the membrane is formed on the wafer, and after the wafer is bonded to the supporting frame, the wafer is back-etched using the supporting frame as a mask.

[0011]

According to the first aspect of the present invention, the wafer is bonded to the support frame before the membrane thin film is etched, so that the support frame is used as a mask to simplify the etching of the membrane thin film.

In the second aspect of the present invention, the wafer is joined to the supporting frame before the wafer is back-etched, so that the supporting frame is used as a mask to simplify the back etching.

[0013]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Next, an embodiment of the inventions of claims 1 and 2 will be described with reference to the drawings. Example 1. 1A to 1E are cross-sectional views showing a method of manufacturing an X-ray mask according to an embodiment of the invention of claims 1 and 2 in the order of steps (a) to (e). Are denoted by the same reference numerals and description thereof will be omitted.

A method of manufacturing an X-ray mask of this embodiment is shown in FIG.
First, as shown in (a), the membrane material thin film 2a is formed on both surfaces of the silicon wafer 1 by a chemical vapor deposition method or the like. Next, as shown in (b),
The silicon wafer 1 is bonded to the support frame 4. And
As shown in (c), the membrane 2 is formed by dry etching the membrane material thin film 2a on the back surface using the support frame 4 as a mask.

Thereafter, as shown in (d), the silicon wafer 1 is back-etched. Finally, as shown in (e), the circuit pattern 3 is formed on the membrane 2.
In the figure, X-ray absorber film formation, resist film formation, exposure,
Development and X-ray absorber etching are collectively shown as (e).

As described above, in the method of this embodiment, the support frame 4 is joined before the back etching of the silicon wafer 1 and the etching of the membrane material thin film 2a, and the support frame 4 is used as a mask. Therefore, special masking for back etching of the silicon wafer 1 and etching of the membrane material thin film 2a becomes unnecessary. Therefore, the manufacture of the X-ray mask is simplified as a whole.

FIG. 2 is a perspective view showing the support frame 4 of FIG. The support frame 4 is made of glass or ceramic,
A rectangular hole slightly larger than the pattern size of the X-ray absorber is provided in the central portion. This hole may be circular or polygonal. Further, when etching is performed using the support frame 4 as a mask, if there is a problem in the etching resistance of the support frame 4,
The surface of the support frame 4 may be protected by, for example, attaching a protective material.

Example 2. Note that, as shown in FIGS. 3A to 3E, the order of the back etching and the pattern formation in the first embodiment may be reversed.

Example 3. Further, the membrane material thin film 2a may be etched immediately before back etching in the procedure of FIG. That is, the order of bonding, pattern formation, membrane material thin film etching, and back etching may be performed in this order.

Example 4. Further, as shown in FIGS. 4A to 4E, pattern formation is first performed on the silicon wafer 1 with the membrane material thin film 2a, and then this is bonded to the support frame 4, and the support frame 4 is used as a mask. , Membrane material thin film 2
The etching of a and the back etching of the silicon wafer 1 may be performed.

Embodiment 5. Next, FIG. 5 shows (a) to (d) a method of manufacturing an X-ray mask according to an embodiment of the present invention.
FIG. 6 is a cross-sectional view showing the order of the steps, which is an example in which the silicon wafer 1 having the membrane 2 attached to only one surface is used.

In the method of this embodiment, first, on one side of the silicon wafer 1, for example, by a single-wafer CVD apparatus or the like,
The membrane 2 is formed as shown in FIG. At this time, the same film may be obtained by etching one surface of the film formed on both surfaces. Next, as shown in (b), the silicon wafer 1 is bonded to the support frame 4. Thereafter, as shown in (c), the silicon wafer 1 is back-etched using the support frame 4 as a mask. Finally, as shown in (d), the circuit pattern 3 of the X-ray absorber is formed on the membrane 2.

As described above, even when only the back etching of the silicon wafer 1 is performed by using the support frame 4 as a mask, the masking dedicated to the back etching is not required, so that the manufacturing of the X-ray mask is simplified as a whole.

Example 6. After the joining step of FIG. 5B, pattern formation may be performed as shown in FIG. 6A and finally back etching may be performed as shown in FIG. 6B.

Further, in each of the above embodiments, the silicon wafer 1 is shown as a wafer, but the wafer material is not limited to silicon.

[0026]

As described above, according to the method of manufacturing an X-ray mask of the first aspect of the present invention, the wafer is bonded to the supporting frame before the thin film of the membrane material is etched. As a result, the thin film of the membrane material can be etched, the process can be simplified, and the manufacturing cost can be reduced. In addition, since the wafer with the membrane material thin film formed on both sides is joined to the support frame, the wafer can be joined to the support frame without warping, which is convenient for maintaining the flatness and parallelism of the membrane. Play.

In the method of manufacturing an X-ray mask according to the second aspect of the present invention, the wafer is bonded to the support frame before the back etching of the wafer is performed. Therefore, the back etching is performed by using the support frame as a mask. This can be performed, the process can be simplified, and the manufacturing cost can be reduced.

[Brief description of drawings]

FIG. 1 is a cross-sectional view showing a method of manufacturing an X-ray mask according to an embodiment of the inventions of claims 1 and 2 in the order of steps.

FIG. 2 is a perspective view showing the support frame of FIG.

FIG. 3 is a cross-sectional view showing a method of manufacturing an X-ray mask according to another embodiment of the first and second aspects of the invention in the order of steps.

FIG. 4 is a cross-sectional view showing a method of manufacturing an X-ray mask according to still another embodiment of the first and second aspects of the invention in the order of steps.

FIG. 5 is a cross-sectional view showing a method of manufacturing an X-ray mask according to an embodiment of the present invention in the order of steps.

FIG. 6 is a cross-sectional view showing a method of manufacturing an X-ray mask according to another embodiment of the second aspect of the invention in the order of steps.

FIG. 7 is a sectional view showing an example of a conventional X-ray mask.

FIG. 8 is a cross-sectional view showing an example of a conventional X-ray mask manufacturing method in the order of steps.

FIG. 9 is a cross-sectional view showing another example of the conventional method of manufacturing an X-ray mask in the order of steps.

[Explanation of symbols]

 1 Silicon Wafer 2 Membrane 2a Membrane Material Thin Film 4 Support Frame

Front page continuation (72) Inventor Moto Hashimoto 8-1-1 Tsukaguchi Honcho, Amagasaki City Central Research Laboratory, Mitsubishi Electric Corporation (72) Inventor Yasuji Matsui 8-1-1 Tsukaguchi Honmachi, Amagasaki Mitsubishi Electric Corporation Central research institute

Claims (2)

[Claims] 1. A method of manufacturing an X-ray mask, comprising: bonding a wafer having a membrane thin film formed on both sides thereof to a support frame, and then etching the membrane thin film using the support frame as a mask. 2. A method of manufacturing an X-ray mask, which comprises forming a membrane on a wafer, bonding the wafer to a support frame, and then back-etching the wafer using the support frame as a mask.