JP3354959B2 - Photomask manufacturing method - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a photo process for manufacturing a semiconductor device, and more particularly to a photo mask.

[0002]

2. Description of the Related Art In recent years, in the manufacture of semiconductor devices, miniaturization has been dramatically advanced. In the photo process, as a measure for miniaturization, the NA of a reduction exposure apparatus and the use of a light source in a shorter wavelength range are measured. In recent years, a remarkable improvement in the performance of a resist has also contributed to the miniaturization. In the half-micron process rule, the technology of the photo process will be established by the above-mentioned technology improvement.

Incidentally, the photomask currently used in the photo process contributes to the improvement of the dimensional accuracy and alignment accuracy in the photo process, and thus the dimensional accuracy and the arrangement accuracy of the pattern on the photomask have been improved. FIG.
It is a figure showing the photomask of the prior art. In the photomask, a thin film of chromium 21 is deposited on a glass substrate 22 made of SiO <SUB> 2 </ SUB> by a sputtering method as shown in FIG. Further, a resist 23 is spin-coated on the chromium 21. This blanks is E
FIG. 2B is a drawing drawn and developed by B or laser drawing. Thereafter, when the chromium 21 is wet-etched using the resist pattern 23 as a mask, FIG.
become that way. These are the conventional photomask manufacturing methods of the prior art. The placement accuracy on the photomask is E
B or depends on the laser drawing stage accuracy and the like, and the dimensional accuracy depends on the drawing accuracy, development, wet etching and the like. By optimizing these factors, it is now possible to manufacture a highly accurate photomask.

[0004]

However, the prior art has the following problems.

There is no doubt that the half-micron process rule requires higher dimensional controllability. In a conventional photomask manufacturing method, an advanced photomask is manufactured by optimizing each process in order to suppress various factors. However, the accuracy of the photomask is approaching its limit especially due to the accuracy of wet etching. In recent years, dry etching has been performed,
Since the shielding portion is generally made of chromium, there is a problem that it is not easy to change the shielding material when it is necessary to change the shielding material due to the influence of corrosion or shortening of the wavelength.

An object of the present invention is to solve the above-mentioned problems, and an object of the present invention is to provide a method for manufacturing a photomask, the method for manufacturing a photomask for improving the dimensional accuracy of the photomask, and a method for manufacturing a photomask. And a method for manufacturing a semiconductor device using the photomask, and a method for manufacturing a photomask in which a shielding material can be selected as needed.

[0007]

A method of manufacturing a photomask according to the present invention comprises the steps of forming a silicon film having a desired pattern formed on a glass substrate, and forming the silicon film on the glass substrate and the silicon film. A step of forming a metal substance thin film capable of forming a film and a metal compound substance; a step of performing a heat treatment to form a metal compound of the silicon film and the metal substance thin film; and the step of not forming the metal compound on the substrate. Removing the metal material thin film in this order.

[0008]

[0009]

FIG. 1 is a diagram showing an embodiment of the present invention. In FIG. 1A, a thin film of Si11 is deposited on a quartz glass substrate 12 made of SiO <SUB> 2 </ SUB> by CVD.

Further, a resist 13 is formed on the Si11 thin film.
Is spin-coated. Here, as in the prior art, the drawing developed by EB or laser drawing is shown in FIG.
(B). Next, using the resist pattern 13 formed by drawing development as a mask, CFC 14 (CF <SUB> 4 </ SU
B>) and oxygen (O <SUB> 2 </ SUB>)
FIG. 1 (C) shows that the resist 13 was peeled off by dry etching of the resist 1. Here, a titanium thin film 14 is formed on the Si pattern 11 and the glass substrate 12 by a sputtering method. Here, by performing a heat treatment at 750 degrees for 30 seconds, the titanium 14 forms a titanium silicide structure with the Si11. Next, when an ammonia water treatment is performed, the portion where the titanium silicide structure is formed remains, and
The titanium 14 on the quartz glass substrate 12 made of O <SUB> 2 </ SUB> is dissolved and disappears. The figure is FIG.1 (D).
In the prior art, chromium was used for the shielding portion, but in the present embodiment, a titanium silicide structure was used.

With this structure, the same light shielding effect as when chromium is used can be obtained. Further, in the prior art, chromium was etched by wet etching or dry etching, but in the present invention, dry etching was used to etch Si. for that reason,
The dimensional controllability was significantly improved. In the prior art, the dimensional accuracy was ± 0.15 μm in consideration of mass productivity, but in the present embodiment, the dimensional accuracy of ± 0.10 μm was possible even at the mass production level.

As described above, in the manufacture of the photomask, the shielding portion of the photomask is made of a compound of Si and a metal substance, so that dry etching can be used unlike the prior art. The dimensional accuracy of is significantly improved. Further by that,
The dimensional accuracy when projecting and exposing on the semiconductor substrate using the reduction exposure apparatus was also improved, and as a result, the effect of contributing to the improvement in the reliability of semiconductor device manufacturing was obtained. In addition, since a silicide structure is used, there is an advantage that a metal substance to be used can be changed as necessary when a problem such as corrosion with chromium occurs, for example, depending on the application.

The embodiment of the present invention has been described above. In addition, (1) In this embodiment, a silicide structure using titanium is used, but tungsten, tungsten, gold, silver or the like is used as a metal material. Use another metal material.

(2) The present invention is used for a shielding portion of a phase shift mask.

(3) A glass material other than quartz glass is used.

It is needless to say that the same advantages as those of the present embodiment can be obtained for the present embodiment.

[0017]

According to the present invention, the dimensional accuracy of the photomask is remarkably improved because silicon is etched in the transmission portion of the photomask. Furthermore, the dimensional accuracy when projecting and exposing on the semiconductor substrate using the reduction exposure apparatus is also improved,
As a result, the effect of contributing to the improvement of the reliability of semiconductor device manufacturing can be obtained. Also, since a silicide structure is used,
There is also an advantage that the metal substance used can be changed according to the application.

[Brief description of the drawings]

FIG. 1 is a view showing a method of manufacturing a photomask according to one embodiment of the present invention.

FIG. 2 is a view illustrating a method of manufacturing a photomask according to the related art.

[Explanation of symbols]

 11 ... Si 12 ... Glass substrate 13 ... Resist 14 ... Titanium 21 ... Si 22 ... Glass substrate 23 ... Resist

Claims (1)

(57) [Claims] A step of forming a silicon film having a desired pattern formed on a glass substrate; and forming a metal material thin film capable of forming a metal compound with the silicon film on the glass substrate and the silicon film. Performing a heat treatment to form a metal compound of the silicon film and the metal material thin film, and a step of removing the metal material thin film on which the metal compound is not formed on the substrate. A method for manufacturing a photomask, comprising: