JPH01166046A - Photomask - Google Patents

Abstract

PURPOSE:To prevent halation by applying a blackened film on the pattern and pattern side face of a previously patterned Ni-P hard mask. CONSTITUTION:The photomask 4 formed by forming a blank by ordinary electroless Ni-P plating on a transparent substrate 5 and patterning the same is immersed into a 0.1-1.0mol/l sodium hypochlorite soln. Said mask is there after subjected to plating by an electroless plating liquid contg. 0.5-1.5mol/l hydrazine salt, by which the black metallic film 3 is formed on the pattern and pattern side face. The light extended into the pattern region by diffraction is absorbed by the photomask if the photomask produced in such a manner is used. The generation of the halation is thereby obviated and the sharp-edged pattern is formed.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a photomask used for forming fine patterns on circuit boards, liquid crystal panels, semiconductors, and the like.

[Conventional technology]

Conventionally, hard masks have been widely used as masks for photolithography processing because of their high durability. Among them, chrome masks are commonly used. In order to prevent halation, the chrome mask uses a chromium oxide film laminated on a chromium thin film as a blank, which is then patterned by photolithography to form a photomask. In this case chrome.

Lamination of chromium oxide films is carried out using a vacuum system using a sputtering deposition method, which has limitations in its applicability to large substrates.

However, recently, in order to accommodate large masks, electroless N1
Photomasks in which a metal film is deposited on a transparent substrate such as glass by P plating and used as a blank have also come to be used. The production of blanks by this electroless plating method is attracting attention because, unlike the sputtering-evaporation method which uses a vacuum system, it uses a simple device and is easily applicable to large sizes.

[Problem that the invention seeks to solve]

However, since the film produced by electroless N1-P plating has metallic luster, it has the disadvantage that when used as a hard mask, a halation phenomenon occurs and the sharpness of the transferred pattern becomes poor.

Further, even in a chromium mask in which chromium oxide is laminated, there is a drawback that the halation phenomenon cannot be completely prevented because the shiny metallic surface is exposed on the side surfaces of the pattern.

[Means for solving problems]

In order to solve the above problems, the present invention has developed a conventional electroless N1
- 0.1 mol/β to 1.0 mol/of a patterned photomask with a blank made by P plating.
After immersing in the sodium hypophosphite solution of A, a black metal film is formed on the pattern and on the pattern side by plating with an electroless plating solution containing 0.5 mol/12 to 1.5 mol/1 hydrazine salt. This is what I did.

[Effect]

When the photomask produced as described above is used, the photomask absorbs the light that has spread around the pattern area due to the diffraction phenomenon, so that no halation occurs and sharp patterning is possible.

〔Example〕

Snc jl! Sensitized by z solution, pdc 122
Tosopnicolone N- on a glass substrate activated by a solution
47 (manufactured by Okuno Pharmaceutical) A 0.35 μm N1-P plating film was deposited using an electroless plating solution, and AZ-1370/
SF (manufactured by Hoechst Japan) positive type photoresist was patterned, etched, peeled and washed, 0.2 mol/j! The photomask shown in FIG. 1 was obtained by immersing the photomask in a sodium hypophosphite solution for 1 minute and plating with a thickness of 0.1 μm using an electroless plating solution containing the following main components.

NiSO44g/1-N2H41,5mol/j! Sodium citrate 0.2 mol/ffi When patterning was performed using the photomask shown in FIG. 1 with a blackened pattern surface, no disturbance occurred in the pattern as shown in FIG.

In order to compare with the above example, N1-P was prepared in the same manner as in the example.
When plating, patterning, peeling, and cleaning were performed and patterning was performed using a non-blackening photomask, the pattern was disturbed as shown in FIG. 3.

〔Effect of the invention〕

As explained above, the present invention can prevent halation by applying a black coating on the pattern and side surface of a pre-patterned Nf-P hard mask, and can improve the precision of the fine pattern shape. Valid for the required product.

[Brief explanation of the drawing]

FIG. 1 is a cross-sectional view of a pattern of a photomask according to the present invention. FIG. 2 is a state diagram of a pattern when patterning is performed using the photomask of the present invention. FIG. 3 is a state diagram when a halation phenomenon occurs. 1...Pattern part 2...Pattern disturbance due to halation 3...N
1-P film 4...blackened film and above Applicant Seiko Electronics Industries Co., Ltd. Figure 3

Claims (1)

[Claims] A photomask in which the upper and side surfaces of the pattern are blackened in a hard mask in which a pattern is formed using a metal thin film on a transparent substrate.