JPS60107651A - Photomask - Google Patents

Abstract

PURPOSE:To enable formation of a fine pattern by forming a layer of oxide of a high m.p. metal, such as Mo, W, or Ta, or oxide of Ni, Fe, Al, or Si between a Cr type thin film formed on a transparent glass base, and a photoresist layer arranged on it. CONSTITUTION:An interlayer 4 made of oxide of Mo, W, Ta, or the like high m.p. metal, or Fe, Ni, Al, or Si is formed between a Cr type thin film 2 formed on a transparent glass base 1 by sputtering, and a photoresist layer 3 arranged on the film 2. The formation of such an interlayer 4 on the film 2 prevents rapid deterioration of surface tension caused by adsorption of organic matters in the air due to the activity of the film 2, and enhances the adhesion of the layer 3. As a result, defective products can be prevented in forming fine patterns and the photoresist can be stored for a long term.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates primarily to a photomask used in semiconductor manufacturing.

Generally, this type of photomask is made by forming a chromium-based thin film consisting of a single layer of chromium or a double layer of chromium and chromium oxide on a transparent glass substrate by snogging, and then coating the surface of the thin film with a photoresist. The surface of a chromium-based thin film obtained by forming a full layer or by sputtering is extremely unstable (active), and it rapidly adsorbs all the substances in the air, lowering the surface tension. The surface becomes hydrophobic and cleaning becomes circular holes E, which makes it easy to peel off from the thin film of commercially available photoresist, and moreover, the photomask coated with photoresist can be used for long periods of time. This results in unsatisfactory parts that cannot withstand the storage of J, and is not suitable for all the processing of detailed patterns that are particularly required in ultra-LSIs and the like.

The purpose of the present invention is to provide a photomask that does not have these disadvantages and is suitable for microfabrication, by forming a chromium-based thin film on a transparent glass substrate by sputtering.
In the method of forming a photoresist layer on the surface of the thin film, oxidation of a high-melting point metal such as molybdenum, tungsten, or tantalum is applied between the chromium-based thin film and the photoresist layer. A layer of iron or nickel oxide, aluminum oxide, or silicon oxide is formed.

Embodiments of the present invention To explain all the drawings, (1) shows a transparent glass substrate, (2) shows a chromium-based thin film formed by sputtering on the surface of the substrate, and (2) shows a thin film made of chromium. It is formed from a single N film of chromium or a two-layer film consisting of a chromium film and a chromium oxide film. (3) is a layer of a commercially available photoresist consisting of a dichromate photosensitive material and polyvinyl alcohol, and is formed on the film-like intermediate layer (4) formed on the top surface of the pork oil film t21 on the S N (3). Provided for. Cough middle layer (4
) is about 260 molybdenum, tungsten, tantalum, etc.
An oxide of a metal with a high melting point exceeding 0 degrees Celsius, an oxide of iron or nickel, an oxide of aluminum, or an oxide of silicon can be thinly formed (preferably formed to a thickness of about 10 OA or less) by total sputtering or vacuum evaporation. ) Koushi 7t fl
Intermediate layer of fluoride (4) becomes unstable, ROM-based film (2)
By forming the photoresist layer (3) on top, a decrease in surface tension is prevented, and the photoresist layer (3) is formed with a large adhesion force (1'*
The intermediate layer (4) is made of a thin layer of chrome-enriched glass substrate 111.
When the chromium oxide thin film fi is formed to a thickness of 0X,
The water contact angle of l does not increase much with time as shown by curve ai A in Fig. 2, and its rate of increase is the same as that of a conventional chromium oxide thin film without an interlayer +41 as shown by curve B. 2) was significantly smaller than in the case of only 2). By forming the intermediate a (4) with a small contact angle, the adhesion with the photoresist layer (3) is the same as above, and it has good chemical resistance that can withstand cleaning and even concentrated sulfuric acid. Similarly, when molybdenum, tantalum, iron, niranal, aluminum, and silicon filaments are vacuum-deposited, the water contact angle of the thin film (2) does not increase much with time, and the photoresist The adhesion of layer (3) was also good.

It should be noted that the intermediate layer (4) can also be achieved by processing at the same time as forming the thin film (2) and incorporating it into the composition of the thin film (2).

In this way, the photomask of the present invention has a layer of high melting point gold such as tungsten, iron or niranal oxide, aluminum, The entire layer of each silicon oxide is formed, which allows the photoresist layer to strongly adhere to the chromium-based PL film, allowing for free cleaning and reducing the number of defective products when forming fine patterns. It has the advantage of being able to be stored for a long period of time.

[Brief explanation of drawings]

FIG. 1 is a sectional view of an embodiment of the present invention, and FIG. 2 is a diagram showing changes in the contact angle of water. (1)...Glass substrate 12J...Chromium-based thin film (3)...Photoresist j~
j(4)・・・2 people outside the middle class

Claims (1)

[Claims] A chromium-based thin film is formed on a transparent glass substrate by sputtering, and then a photoresist R' is applied to the surface of the thin film.
! In the il-forming type, an oxide of a high-melting point metal such as molybdenum, tungsten, or tantalum, an oxide of iron or nickel, or an oxide of aluminum is used between the chromium-based thin film and the photoresist layer. A photomask consisting of a full layer of oxide or silicon oxide.