JPS61159633A - Formation of negative type resist composition and negative type resist pattern - Google Patents

Abstract

PURPOSE:To enhance resolution and dry etching resistance by incorporating hydroxybenzophenone naphthoquinonediazidosulfonate to prepare a negative type resist compsn. for ionizing radiation. CONSTITUTION:The naphthoquinonediazidosulfonate of hydroxybenzophenone, such as 2,3,4-hydroxybenzophenone, 2,4-hydroxybenzophenone, or 2,4,4'- hydroxybenzophenone, is incorporated to prepare a negative type resist compsn. for ionizing radiation. The film made of this compd. is formed on a substrate is selectively irradiated with the ionizing radiation, and the unexposed areas are developed off with an org. solvent to form a negative type resist pattern.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to a negative-appearing renost composition for ionizing radiation and a method for forming a renost pattern thereof.

(Prior Art) (Problems to be Solved by the Invention) In recent years, the demand for higher integration of semiconductor devices, etc. has been increasing, and along with this, the demands for forming fine 9-turns have become even more severe. It is becoming.

Conventionally, a transfer method using ultraviolet rays has been used in phosphorography for LSI, etc., but due to the above requirements, in the future
In the formation of fine t4 turns described below, it is expected that there will be a greater reliance on phosphorography using shorter wavelength ultraviolet rays, that is, far ultraviolet rays, in order to improve resolution.

In addition, when manufacturing the above-mentioned LSI etc., the presence of fine irregularities on the substrate used cannot be avoided, and there is a risk that the AI eter μ may deteriorate due to the influence of reflection from these fine irregularities during exposure. A multilayer resist system has been proposed as a method for preventing such pattern deterioration, and the resist used therein is usually formed thinly as an upper layer. Moreover, the performance required of such renost is that it has high sensitivity to the deep ultraviolet rays, good resolution, and high plasma resistance.

On the other hand, in phosphorography using deep ultraviolet rays, the wavelength thereof is about 200 nm, and it is thought that the resolution reaches a limit at about 0.5 μm. 0.5 μm like this
In the following lithography.

Other electron beams, X111 or ion beams may be used, but resists sensitive to these high-energy beams are required to have high resolution and dry etching resistance.

Polymethyl methacrylate (abbreviated as PMMA), for example, is generally well known as a resist for microfabrication, and all of these are polymeric resists with a molecular weight of 10,000 to 1,000,000.

If we consider the ultimate resolution here.

It is desirable to use a renost material with a low molecular weight and high dry etch resistance, and among these materials, one that shows high sensitivity to ionizing radiation such as the deep ultraviolet rays and EB. However, no such resist material has been proposed at present.

(Means for Solving the Problems) In view of the above-mentioned conventional problems, the present inventors have conducted intensive research and have developed a low-resolution film that has high resolution, excellent dry etching resistance, and practical sensitivity. Jin's invention was achieved by discovering a resist material with a molecular weight of renost.

This composition is a negative extraction solution for ionizing radiation, and is characterized in that it contains a film of this 7-toquinone dianodosul heptaonic acid ester of hydroxybenzophenone. , is a method for forming a negative resist pattern characterized by developing and removing unirradiated areas with an organic solvent.

In this invention, the hydroxybenzophenone is 2% in addition to 2,3.4- and 2-4-hydroxybenzophenone shown in Examples below.

Hydroxybenzophenones such as 1, 1 and 3.4- may be mentioned.

(Function) In the present invention, the hydroxybenzophenone 7-toquinone dianodosul heptaonic acid ester itself is used as the above-mentioned negative-tone material for ionizing radiation, and it has a low molecular weight and is equivalent in other above-mentioned properties. It is considered that it is better to solve the above problem than to give comparable results.

(Example) The present invention will be specifically explained below with reference to Examples.

-1) in methylcellosolve acetate,
This solution was passed through a 0.5 μm filter, and then
Spin coating was performed on a silicon substrate to form a resist cross section with a thickness of 0.4 μm. After heat treating the substrate with this resist film at a temperature of 80°C for 20 minutes,
0-300 nm) KID.

The Jeddah turn was drawn using the contact exposure method. The dose amount was 20 mJ/cd. After that, development was performed at 23° C. for 20 seconds using a mixed solution of chlorobenzene and cyclohexane at a volume ratio of 10/2, resulting in lines and spaces of 0.5 μm and 0.5 μm.
μm spaces were resolved.

The cross section of the obtained resist was also scanned using a scanning star electron microscope (SEM).
Upon observation, it was found that a good overhang was formed in the cross section of the resist.

Example 2 A film was formed on a substrate and exposed to light in the same manner as in Example 1 except that 2) was used. The thickness of BA-2 is 0.
The thickness was 3 μm, and the dose was 30 mJ/cd.

When development was carried out at 23° C. for 15 seconds using a mixed solution of isoamyl acetate and cyclohexane in a volume ratio of 10/2 as a developer, lines and spaces of 0.5 μm and spaces of 0.5 μm were resolved.

1 ionate ester (hereinafter abbreviated as LMR) on a Si substrate.
．． It was coated with a thickness of 5 μm and baked at 150°C for 30 minutes. Next, on this substrate, 910
0nm S10 was evaporated and the BA-1 was further KO, 24m thick.
coated. The obtained substrate was baked at 60° C. for 30 minutes, and exposed and developed in the same manner as in Example 1 at a dose of 20 mυ−. Then, SIO and layer etching was performed using CF and plasma using a parallel plate plasma etching apparatus. The etching conditions in this case are power density: 0.16 W/c14. ! Cutting gas pressure;
aopa I gas flow rate: 50 SCCM for 2 minutes. Thereafter, etching of the above I and MR was performed using the same apparatus. The etching conditions were: 4W density: 0.16 W/cwt.

Etching gas pressure: 20 Pa *Gas flow rate: 20
It was set to 7 minutes in SCCM. In the same way as above, use SEM to find out!
- When the line and space was observed, a line and space of 0.5 μm was obtained, and the cross-sectional shape was a good rectangle.

Example 4 1.5 μm μm bispin coating of KLMR on 81 substrate This substrate was baked at 150° C. for 30 minutes. The above BA-1 was baked on the LMR with a thickness of 3 μm at 80° C. for 20 minutes. The following was exposed and developed under the conditions of an accelerating voltage of 20 KV and a dose of 20 μC/d according to Example IK.
n patterns were formed.

Comparative Example A film was formed on a Si substrate and exposed in the same manner as in Example 1 using the above BA-1. Thereafter, development was carried out for 60 seconds using an Az developer (alkaline aqueous solution), but no resist/4 turns could be formed.

(Effect of the invention) As mentioned above, this invention
By using a low-molecular organic substance, toquinonediazide sulfonate ester, as a resist, higher resolution can be obtained compared to conventional resists using polymers. It contains a large amount of phenyl groups and has excellent dry etching resistance, and therefore can form high-performance fine arm turns, and has great industrial value, especially when used in the production of highly integrated semiconductor parts.

Claims (2)

[Claims] (1) A negative resist composition for ionizing radiation characterized by containing a naphthoquinonediazide sulfonic acid ester of hydroxybenzophenone. (2) Forming a film of naphthoquinonediazide sulfonic acid ester of hydroxybenzophenone on the substrate,
A method for forming a negative resist pattern, which comprises selectively irradiating the resist with ionizing radiation, and developing and removing unirradiated areas with an organic solvent.