JPH0234856A - Pattern forming method - Google Patents

Abstract

PURPOSE:To improve a yield for obtd. a pattern forming element by applying a water-soluble resin material contg. a diazonium compd. onto a photosensitive resin, and forming a pattern by exposing and developing the resin. CONSTITUTION:After applying a water-soluble resin material 2 contg. a diazonium compd. onto a negative resist on a base plate 1, a pattern is formed by exposing the resin material through a mask 3 and then developing. Suitable diazonium compds. are, for example, 4-morpholinobenzene diazonium salt, 4- anilinobenzene diazonium salt, 4-(N,N-dimethyl)aminonaphthalene diazonium salt, etc. Suitable water-soluble resins are, polystyrene sulfonic acid, polystyrene carboxylic acid, etc. Since a fine pattern is obtd. easily with a high aspect ratio by this method, a yield of the prepn. of semiconductor elements may be increased.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to a pattern forming method used in the manufacturing process of semiconductors and the like.

Among the conventional technology semiconductor manufacturing processes, photolithography
There are often cases where negative resists are used. However, there is a problem in that when a pattern is formed using a normal negative resist, the shape becomes an inverted trapezoid.

A conventional pattern forming method using a negative resist will be described with reference to FIG.

RU-110o, which is a negative photoresist, is placed on the substrate 1.
Add 1.2 μl of N (Hitachi Chemical) 2 (Figure 2).
, exposure 5 was performed using an i-line stepper (N: 0.42) through a mask 4. (FIG. 2B) Thereafter, development was performed for 60 seconds using an alkaline developer, RD developer (Hitachi Chemical), to form pattern 2B (FIG. 2G). However, 0
．． The 6 μm line and space pattern 2B was an inverted trapezoid (angle 7o0). Such an inverted trapezoidal pattern causes dimensional variations in subsequent etching steps, etc., which is a cause for concern as it leads to a decrease in device yield.

Problems to be Solved by the Invention It is an object of the present invention to solve the problem of defective pattern shapes (inverted trapezoids), which conventional pattern forming methods had.

In order to solve the problems of the prior art, the present invention is characterized in that a water-soluble resin material containing a diazo compound is applied onto a negative resist, and then a pattern is formed by exposure and development. This is a pattern forming method.

Effect: According to the method of the present invention, a vertical profile pattern can be formed with high precision using a negative resist.

This is thought to be largely due to the diffusion of the diazonium compound in the water-soluble resin material into the resist.
The inventors have found that this effect is particularly strong when the resin has sulfonic or carboxylic acid groups. This is considered to be because these acid groups facilitated the diffusion of the diazo compound. Note that the diazo compound decomposes upon exposure to light, but during this decomposition, the reaction of the azide compound in the resist, which was previously insufficiently hardened at the bottom of the resist, is promoted and hardens to the bottom of the resist, eliminating the inverted trapezoidal pattern. It is thought that a steep pattern is formed.

Examples of the diazonium compound of the present invention include 4-morpholinobenzenediazonium salt, 4-anilinobenzenediazonium salt, and 4-(N,N-dimethyl)aminonaphthalenediazonium salt.

As the water-soluble resin of the present invention, polystyrene sulfone f
ll, polystyrene carboxylic acid, and the like.

Example (Part 1) A material having the following composition was prepared as a water-soluble material containing a diazonium compound according to the present invention.

Figure 1 shows a pattern forming material according to an embodiment of the present invention using this material. I will explain using

ItU-11oo
N2 was added at a concentration of 1.2/lZm (Fig. 1), and 0.2 μl of the water-soluble material 3 was formed on the upper layer (Fig. 1B).

A full 6" exposure was carried out using an i-line stepper (NAo, 42) through a mask 4 (Fig. 1C). After that, development was performed for 60 seconds using an alkaline RD developer to remove the water-soluble material. The film was removed, and two patterns were formed (Fig. 1D).The two patterns obtained were 0.6 μm line-and-field with an aspect ratio of 9o0 and no inverted trapezoidal development.
It was a space pattern.

(Part 2) A material having the following composition was prepared as a water-soluble material containing a diazonium compound according to the present invention.

Using this material, we also used RD-200ON as a resist.
(Hitachi Chemical) 1.2 μm thick, exposed to KrF Part 1
A pattern with a similar good aspect ratio was obtained.

Effects of the Invention By using the pattern forming material of the present invention, it is possible to easily form fine patterns with a high aspect ratio in the semiconductor manufacturing process, which improves the yield of semiconductor device assembly and has great industrial value. big.

[Brief explanation of the drawing]

Figures 1-C are cross-sectional views of a pattern-forming method using a pattern-forming material according to an embodiment of the present invention, and Figures 2-G are cross-sectional views of a pattern-forming method using a conventional pattern-forming material. It is a diagram. 1...Substrate, 2...Pattern forming material of the present invention, 3...Mask, 4...KrF excimer laser light.

Claims (2)

[Claims] (1) A pattern forming method characterized by forming a pattern by coating a water-soluble resin material containing a diazonium compound on a photosensitive resin that is cured by ultraviolet light, and then exposing and developing the resin. (2) The pattern forming method according to claim 1, wherein the water-soluble resin material has a sulfonic acid group or a carboxylic acid group.