JPS6259956A - Mask for pattern formation - Google Patents

Abstract

PURPOSE:To form a pattern with good accuracy by using an org. compd. contg. a diazo group which generates a change in the transmittance characteristic of light when irradiated with light or charged particles for a film to be formed on a mask plate. CONSTITUTION:The thin film layer 1 consisting of the org. compd. or the like contg. the diazo group which generates a change in the transmittance of light when irradiated with light or charged beam 3 is provided on a transparent glass plate 2 consisting of quartz, etc. The transmittance of the light increases to form a transmittable region 4 for light in the region of the layer 1 where the light or the beam 3 is irradiated. The process for manufacturing the mask which is hereto required in the conventional practice is eliminated if the pattern is formed in the above-mentioned manner.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Field of Application] The present invention relates to a pattern forming mask using a diazo compound as a mask material.

[Conventional technology]

Conventionally, device patterns such as semiconductor elements have been made using silicon (S).
A commonly used method for transferring images onto a substrate such as t) is 1, a method of patterning a resist film formed on a substrate by a light exposure method using a chromium (Cr) mask. The mask used in this method is a thin film of metal such as Cr formed on a transparent substrate such as quartz.

A resist is coated on this gold M* film, a pattern is drawn using an electron beam, an ion beam, etc., and a pattern is formed by etching the metal thin film. In other words, since light passes through the parts where the metal thin film has been removed, when a sample coated with resist is placed under this mask plate and irradiated with light, the mask pattern is transferred to the resist on the sample. .

[Problem that the invention seeks to solve]

In this conventional pattern forming method, the dimensional accuracy and pattern arrangement accuracy of the formed pattern are determined by those of the pattern formed on the mask plate. In order to form a pattern on the mask plate, the metal thin film must be removed by etching, which causes the following problems. In other words, a pattern is drawn on a resist coated on a thin metal film using an electron beam, and after processes such as development and haking of the resist are performed, the thin metal film is etched by, for example, a plasma etching method. At this time, there are variations in the dimensions between the center and the periphery of the mask plate.

This is due to non-uniformity of the plasma, non-uniformity of the temperature of the mask plate itself, and variation in the etching rate. On the other hand, in the method of etching a metal thin film using an acid or alkaline solution, a phenomenon called side etching occurs, and it is particularly difficult to form submicron patterns of about 1 μm or less. This is because the etching progresses isotropically, so the pattern dimensions change with the etching time, and the proportion of deviation in the designed pattern dimensions increases for fine patterns.

Next, there is a problem in that the process of forming a pattern on a mask plate requires advanced technology as the pattern becomes denser and more precise. In other words, it is often necessary to use a technique for correcting pattern defects that occur during the etching process of metal thin films. As a result, the cost of the mask plate becomes extremely high.

This invention was made to solve the above-mentioned problems, and it can omit many processes such as development, baking, and metal etching that are required when using conventional mask plates, and it also reduces pattern size. The company's commitment is to provide a pattern-forming mask that has less variation in the pattern than conventional ones.

[Means for solving problems]

The pattern forming mask according to the present invention is made by forming a film of an organic compound containing a diazo group on a transparent glass plate such as quartz, which causes a change in light transmission characteristics when irradiated with light or a charged beam, and can form a pattern. The plate is formed by irradiating the sample with light or charged particles to make the desired area on the plate transparent.

[Effect]

In this invention, the film to be formed on the mask plate is made of an organic compound containing a diazo group that becomes transparent when irradiated with light or charged particles, which simplifies the mask manufacturing process. Good pattern accuracy,
Moreover, pattern formation without pattern defects can be performed.

〔Example〕

An embodiment of the present invention will be described below with reference to the drawings.

It is a well-known fact that certain diazo compounds change the light transmission properties of light (for example, Proceedings of the 32nd Japan Society of Applied Physics (1985), p. 297), and the present invention uses this organic compound as a transparent glass such as quartz. The plate on which the film is deposited is intended to be used as a mask material in place of the conventionally used glass plate on which the gold KM film is deposited.

1 and 2 show a method of manufacturing a pattern forming mask according to an embodiment of the present invention. In FIG. 1, 3 is light or a charged beam, and 1 is an organic compound containing a diazo group that changes its light transmission characteristics by irradiation with the light or charged beam 3 (Reference: L.F. Halle, Vacuum Technology Magazine). L, F.

Halle, J., Vac, Se4. Tech, )B
3 (1), p. 323, 1985), and 2 is a transparent glass plate made of, for example, quartz. In the region of the thin film layer 1 irradiated with the light or the charged beam 3, the light transmittance increases, and a light transmitting region 4 can be formed as shown in FIG.

FIG. 3 shows a method of forming a pattern using the mask produced as described above; as shown in FIG.
A pattern can be formed on the resist 6 coated thereon by the same method as in the prior art. That is, conventional Cr
A transparent glass plate coated with an organic compound is used instead of a mask in which a metal layer such as the above is formed on a transparent glass plate.

According to this method, many processes required in conventional mask manufacturing processes can be omitted. For example, conventionally, in order to pattern a metal layer such as Cr, it has been necessary to perform processes such as developing a resist coated on the metal layer, etching a gold slurry, and removing the resist. However, according to the method according to the present invention, a mask plate can be manufactured only by the process of irradiation with light or a charged beam. This means that the chances of pattern defects occurring, which are a major problem with conventional methods, can be significantly reduced.

Unlike conventional methods, there is no need to control many parameters such as development conditions, baking conditions, metal etching conditions, etc.

These results indicate that the method of the present invention can significantly shorten the turnaround time of the mask plate compared to the conventional method.

On the other hand, with respect to the problem of quality deterioration due to repeated use of mask plates, the method of the present invention provides advantageous results compared to conventional methods. In other words, in the case of a mask plate using a conventional metal thin film, the mask plate I
・It is necessary to wash this to remove the dirt.

During this cleaning process, peeling of the gold B thin film, generation of pinholes, etc. are likely to occur, and the quality of the mask plate deteriorates as the number of times the mask plate is cleaned increases.

However, when using the mask plate according to the present invention, the thin film of the organic compound coated on the transparent glass plate must be removed and the same organic compound must be coated again. Even assuming that an electron beam is used, for example, 256K DRAM
In the case of (dynamic RAM) patterns, it only takes about 20 to 40 minutes, so it is about the same time as conventional mask plate cleaning and defect inspection, so it does not pose a problem and of course it does not affect the mask quality. There is no problem of deterioration.

〔Effect of the invention〕

As described above, according to the present invention, instead of a conventional metal thin film, the film to be formed on the mask plate is an organic compound containing a diazo group that causes a change in light transmission characteristics when irradiated with light or charged particles. By using this method, pattern formation can be performed under conditions that are more advantageous than conventional methods in terms of pattern accuracy and pattern defects, and the mask manufacturing process can be simplified, which has the effect of reducing mask costs. .

[Brief explanation of drawings]

1 and 2 are diagrams showing a method of manufacturing a mask plate according to an embodiment of the present invention, and FIG. 3 is a diagram showing a method of forming a pattern using the mask plate of the above embodiment. 1...Thin film, 2...Transparent glass plate, 3...-
light or charged beam, 4... light transmission region, 5... light,
6-...Resist, 7...Substrate. Note that the same reference numerals in the figures indicate the same or equivalent parts.

Claims (1)

[Claims] (1) A film of an organic compound containing a diazo group whose light transmission characteristics change when irradiated with light or charged particles is formed on a transparent plate, and then irradiated with light or charged particles to form a film on the plate. A mask for pattern formation, characterized in that it is formed by making a desired portion of the mask transparent.