JPS59180560A - Photomask - Google Patents

Abstract

PURPOSE:To enable direct formation of a pattern by coating the blank face of a hard mask with a photoresist and further coating it with a photographic emulsion composed of a photosensitive silver salt. CONSTITUTION:A hard mask 5 comprises upward from below a glass substrate 1, a vapor deposited film 2 of a metal, such as Cr, Cr oxide, or Fe oxide, a photoresist layer 3 of a positive or negative type, formed on the film 2, and a silver salt photosensitive emulsion layer 4, such as photographic emulsion layer high in sensitivity formed by dispersing silver halide, such as AgCl or AgBr, and a sensitizer into gelatin. As a result, the photosensitive emulsion layer 4 high in sensitivity composed of silver halide is formed on the hard mask blank resist layer 3 of a circuit pattern type, and direct pattern formation using a light source, such as photoplotter in an art work printing system, is made possible.

Description

DETAILED DESCRIPTION OF THE INVENTION (a) Technical field of the invention The present invention comprises: 1, S■, relates to a photomask for forming circuit patterns related to hybrid IC manufacturing.

(b) Background of the technology Photomasks that form light-shielding images, especially heart masks that use thin metal films as light-shielding films, are widely used for pattern drawing of various IC circuits because of their high surface strength and excellent durability. There is.

The present invention is intended to realize a mask with fewer defects by shortening the mask manufacturing process, and proposes a hard mask that uses a highly sensitive photographic emulsion.

(C) Conventional technology and problems Conventionally, the circuit pattern drawing (patterning) of a hard mask using a metal vapor-deposited film mask such as chrome or tankle has been done by coating a photoresist made of photosensitive resin on a mask blank (positive type). This is generally done using an exposure transfer method from a separately prepared artwork film or a photographic plate used to form a circuit master plate.

However, since the sensitivity of the bottom resist is lower than that of the photographic emulsion, it is difficult to directly transfer the pattern (artwork pattern) to the bottom resist pattern (artwork pattern) using the CAI method of mask manufacturing. There is a drawback that it cannot be drawn.

Furthermore, the exposure transfer method described above uses so-called contact transfer with a photographic plate, but in this case, the flatness of the mask is poor and poor adhesion with the dry plate is likely to occur, and if dust gets between the contact surfaces, faithful transfer cannot be achieved. It won't happen. For this reason, there are problems such as the possibility that fine pattern defects may occur.

(d) Purpose of the invention The present invention is to solve the above problems.

The present invention is directed to realizing a photo mask that enables direct drawing of the pattern by forming a highly sensitive photographic emulsion layer on a conventional heart mask blank.

(e) Structure of the Invention The above object is to manufacture a mask pattern for drawing a high-free 71''l(', etc. circuit in a bar 1 mask.

Apply photoresist to the hard mask flank surface.

Furthermore, this can be achieved by applying a true emulsion (of a silver salt photosensitive composition) to the resist coated as described above to form a polymask.

(f) Embodiment of the Invention FIG. 1 is a cross-sectional view of a heart mask showing an embodiment of the invention, and FIG. 2 is a process diagram of pattern production using the hard mask shown in FIG.

In the cross-sectional view of FIG. 1, 1 is a glass substrate, and 2 is a metal therapeutic film with low reflectance and high surface strength, such as chromium, chromium oxide, or iron oxide. The cross-sectional view shows the original element H in a state called a blank plate.

3 is a photoresist layer having either a positive type or negative type composition coated on the metal vapor deposited film 2;

4 is the silver salt photosensitive emulsion layer of the present invention, for example, halogenated AgC1 or AgBr etc. 1)! , and a high-sensitivity photographic emulsion layer in which a sensitizer is dispersed in seratin.

The method of forming a mask pattern of the present invention from the heart mask flank 5 of the structure shown in FIG. 1 will be explained with reference to FIG.

In the process diagram of FIG. 2, A is the so-called exposure step of the photographic processing process in which a pattern is drawn on the silver salt photosensitive emulsion layer 4 of the heart mask 5, and B is the pattern development and fixing process for the exposed silver salt photosensitive emulsion. A black and white Bakun negative or reversal negative as a visible drawing pattern is obtained.

C is a step of exposing the entire surface to ultraviolet light, in which the m-shaped pattern of the silver salt photosensitive emulsion 4 is printed onto the photoresist layer 3.

Further, D is an etching (development) step for the photoresist layer 3 which has been baked in step C.

In the etching (development) step, as described above, there is a negative shape and a bulge shape due to the dark blue color of the coated resist layer.

Hereinafter, the photomask of the present invention explained in Examples is 2.
Hard mask flank resist layer 3 for circuit pattern formation
``High sensitivity to -'' photosensitive silver saponide composition') Since true emulsion I is formed, an example is 1-F' I: 7 in the artwork 161-image system. It becomes possible to draw a superimposed pattern using a light source such as a tungsten light bulb.

(g) Effects of the Invention According to the photomask of the present invention, it is possible to obtain a hard mask which can be subjected to pattern development using xenon and tungsten light or directly patterned with a photoplotter. Furthermore, in the case of conventional problems, since the upper culm of one circuit pattern does not enter, there is no accompanying low pattern accuracy or the introduction of back-up defects during transfer.

Furthermore, it is clear that the mask manufacturing process can be shortened.

From this point of view, the effects of the present invention are significant.

[Brief explanation of the drawing]

FIG. 1 is a sectional view showing an embodiment of the photomask structure of the present invention;
FIG. 2 is a diagram illustrating a pattern forming process using the mask shown in FIG. In the figure, 1 is a glass substrate, 2 is a metal treatment film, 3 is a photoresist layer, 4 is a high-sensitivity photographic emulsion layer, and 5 is a heart mask blank of the present invention.

Claims (1)

[Claims] A hard mask for producing a mask pattern for drawing circuits such as hybrid ICs is characterized in that a resist of photoresist cloth and a photographic emulsion of a silver salt photosensitive composition are coated on the heart mask blank surface. Photomask.