JPS5984519A - Developer - Google Patents

Abstract

PURPOSE:To improve fluctuation in dimensions of figure and also improve distribution within the wafer surface in dimensions of figure by forming the developer of photo resist consisting of polyglycidyl methacrylate mainly with dioxane or cyclohexanone or a mixture of them. CONSTITUTION:The PGMA resist liquid is applied to the mask substrate where chromium is vacuum deposited on a glass plate and this substrate is then heat processed. Thereafter, a figure is delineated with electron beam using an electron beam exposing apparatus. After a figure is delineated, the substrate is left in the vacuum ambient, the mask substrate is taken to the outside of apparatus and is developed. For the development, a spray developer is used. The mask is sprayed by the cyclohexanone while it is rotating wity the center in the vertical direction considered as the axis. Then, it is sprayed by MIBK and is rinsed. Finally, the mask is rotatingly dried up while the rinse solution is splashed with nitrogen.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention provides polymethyl glycidyl acrylate (hereinafter referred to as P
GMA and abbreviation. ) (%[1ti
This relates to a developing solution for (ray resist).

PGMA as an electron beam resist with high sensitivity and high resolution
There is. This resist has an IT average molecular weight of 100,000, and the resist residual wA height is 50% when exposed to an electron beam of 10 KV.
The sensitivity that can be reached is 0.4 μO/cdt, and it can be practically formed with a fine line 1 of 1 μm.

This resist was prepared by soaking the PGMA polymer in a bath medium.
It is supplied as a resist solution of 5 to 35 centivoise.

Apply this liquid to ueno etc. 41j L,, 80°~10
Heat treatment at 0°C for 10 to 30 minutes.

This metal is placed in an electronic device and a figure is drawn in a vacuum, and then it is immersed in a full atmosphere and then placed in a mold to make the drawn figure appear.

The bM ratio of methyl ethyl ketone (MffiK) and ethyl alcohol is 4.
: Spray about 1 needle of mixed metal from 1 to 8:l, then lightly spray methyl isobutyl ketone (MlBK) and rinse.Finally, spray the rinsing liquid by rotating it at a flat speed while spraying the rinsing liquid. Wash and dry.

In the above developer, gBK is a good solvent for the unexposed polymer, and ethyl alcohol is a poor solvent.

And, the mixture of the two excites J:ri, the phenomenon of low expansion.

However, the tMt point of Mgxi is 80°C, and the tMt point of ethanol is 78°C, and both have a high vapor pressure and evaporate during spraying, so it is necessary to exhaust the current chamber, but these solvent vapors If it is exhausted, environmental conservation earth retention will not be possible.

Since MEK creates a crosslinked resist pattern, the exposed area swells and deforms after drying, resulting in variations in the line width of the resist pattern, and the fine pattern differs from the established line width.

The purpose of ``Fugitive pH'' is to provide a standard developer for PGMA that eliminates these problems.

In the process of devising the four investigations, Unexploded Town Name discovered the following.

To prevent the evaporation of the compound, it is best to use a solvent with a low vapor pressure. Solvents for preparing uncrosslinked PGMAt include acetone, cyclohexanone, dioxanetetrohydrofuran, and the like. Of these, cyclohexanone has a boiling point of 156'c
,'! Dioxane is heated at 101° C. and has a much lower vapor pressure than MEK, so there is less evaporation during spraying.

In addition, since dioxane and cyclohexanone alone are critical solvents for uncrosslinked P()MA, they can be used as a developer without being mixed with a poor solvent.

Therefore, it has been found that dioxane, cyclohexanone as a single solvent, or a mixture of bathing mediums can be used in a liquid solution. Furthermore, the solvent list of dioxane and cyclohexane is MEK
It has been found that it works well when mixed with a small amount of benzene chloride, cellosolve acetate, etc. to strengthen the dissolving power and used in the developer. The mixing ratio should be 20% by volume or less.

By using this developer, deformation of resist figures that occur during development can be reduced, and scum (resist residue) generated between figures can be reduced. Therefore, the variation in the dimensions of the figure can be improved, and the distribution of the figure dimensions in the wafer and in the plane is improved. Further, with a fine figure of 2 pm or less, the deviation noise between the design value and the 'electron beam drawn figure size can be reduced.

Further, since the present developer has a low vapor pressure, there is little evaporation due to spraying, and therefore, a decrease in the wafer temperature due to the latent heat of evaporation of the developer 11 can be ignored. Therefore, the developing conditions become constant, which is one of the reasons why the writing border characteristics of the resist figure dimensions are improved. This low vapor pressure also helps with the environmental problems mentioned above.

Furthermore, since ethanol has a vapor pressure of 79 mmHg at 30°C, and MBK has a vapor pressure of 100 mmHg at 26°, MEK evaporates during storage9 and the liquid composition changes. However, in the developer according to the present invention, compositional changes do not occur during storage spray.

In addition, when using a mixture of dioxane and/or cyclohexanone with other components as the developer of the present invention,
Above pond, non-solvent methyl isobutyl ketone klO
:Can also be mixed in a ratio of 1 to 20 to 1.

In a negative resist, unexposed areas dissolve in the developer, while exposed areas become insoluble in the developer because crosslinking occurs between polymer molecules to form giant network molecules. However, the crosslinked resist swells as solvent molecules enter the network structure.

Then, by rinsing, the solvent molecules are drawn out from the mesh, and the resist pattern contracts. If excessive force is applied during the swelling and shrinking process of the resist figure, the resist network will be deformed from the arrangement at the time of drawing after rinsing and drying, and this non-uniform deformation will cause variations in line width.

In order to prevent this deformation from occurring, it is best to use a developer with less swelling, or to take care not to apply force during rinsing. According to the present invention, since cyclohexane or dioxane, which has a slow dissolution rate for the unexposed polymer of MKK technology, is used as a developer, these solvents have little interaction with PGMA, so they do not cause excessive shrinkage during rinsing. No force is applied.

Hereinafter, the present invention will be explained in more detail with reference to specific implementations.

Example: A mask substrate with 90 am of chromium vaporized on a glass plate.
Apply GMA resist solution R to form a film with a N thickness of 500 nm. After heat treatment at 30°C for 30 minutes, an electron beam accelerated to 10KV was used to expose 0.6μ
Draw a figure with a dose of 07-. After writing, leave it in the vacuum for 30 minutes, and then remove the mask substrate from the apparatus.
*Take it out and develop it.

For development VC, a through-developing machine is used, and the mask is rotated at about too pm with the axis perpendicular to the center of its surface, dioxane is sprayed for 50 seconds, and then K' is sprayed from M.
Spray for 25 seconds and rinse. At the very end, remove the rinsing liquid with nitrogen, and then dry by rotation at a rotational speed of 1500 r, p, tn.

After post-baking at 1f111.140' for 30 minutes, it was placed in this mass-fed plasma asher, and after being evacuated, an air chamber was introduced to bring the temperature to 133 Pascals and the plasma was released, leaving nothing between the resist patterns. Eliminate the scum that exists. Next, chromium is completely etched using a cerium-ammonium nitrate aqueous solution, and finally, the resist is removed using oxygen plasma or the like.

A chrome mask can be manufactured in this way.

Example: Si formed on the surface to a thickness of 5iOzkl# and 500ny+t.
Apply 600 nm of PGMA to Milani and heat at 90°C.
Bake for 155 minutes. This is then exposed to an electron beam with an acceleration voltage of 20 KV and a radiation dose of 1 m#) 1.3 μ0/ca.

For development, spray cyclohexanone: MffiK at a % volume needle ratio of s:l for 1 minute in a mixed solution basin, then spray Ky for 30 seconds from M as a rinsing solution. After rotation drying,
Beta to ℃, carried out 11 and colleagues to remove scum with plasma asher? and then a 1:1 mixture of saturated ammonium butoxide solution and 50X butyric acid7. After etching for 1 minute at 25°C, wash with water and spin dry.

In this way, sio! To form a pattern on the film and remove the unnecessary PGMA'ii, add sulfuric acid and 30% 2i! r
Immerse it in a mixture of hydrogen hydride 7 and remove it by oxidizing the resist.

This development method can be applied to the development of PGMA (electron beam regime) and is used in the production of chrome masks for photolithography. In addition, yf: direct writing without a photomask for integrated circuits, yf: direct writing by applying and processing, and b can be applied to direct processing of bubble memories, etc.

9

Claims (1)

[Scope of Claims] 1. A developer for a photoresist made of polymethylglycidyl acrylate, the developer having dioxane, cyclohexanone, or a mixture thereof as main components. 2. Dioxane A certain sail is made by mixing cyclohexanone or a mixture thereof with methyl ethyl ketone, selon acetate, benzene chloride, etc., which are bathing media for polymethyl glycidyl acrylate, at a volume of 20% or less. The developer described in Section 1. 3. Mix dioxane or cyclohexanone or a mixture thereof with methyl in butyl ketone or l, which is a non-solvent.
A developer as described in item 1 of the Particular IfF Information Scope, wherein the developer is mixed in a ratio of O:1 to 20:1.