JPH05166717A - Formation of fine pattern - Google Patents

Abstract

PURPOSE:To provide a method of forming a fine omission of pattern with a pattern size smaller than the resolution limit. CONSTITUTION:After a fine omission of pattern is formed on a pattern forming resist 2, a mixing generating resist 3 which mixes itself with the pattern forming resist 2 is coated. Then baking is performed to form a mixing layer 4 and then the mixing generating resist 3 except for the mixing layer 4 is removed. So, developing is performed for obtaining a fine pattern size c which is smaller than a pattern size 'a' of the fine omission of pattern formed on the pattern forming resist 2 by the thickness b of the mixing layer 4.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a fine pattern forming method used for manufacturing a semiconductor device.

[0002]

2. Description of the Related Art FIGS. 2A and 2B are sectional views showing a conventional fine pattern forming method. In this figure, 1 is a substrate such as a semiconductor, 2 is a pattern forming resist applied on the substrate 1, and a is a pattern size.

Next, a forming method will be described. Figure 2
As shown in (a), the pattern forming resist 2 is applied and formed on the substrate 1. Next, as shown in FIG. 2B, the pattern forming resist 2 is optically exposed, for example, at a wavelength of 365.
A fine relief pattern is formed by using a reduced projection exposure method of nm, an electron beam (EB) exposure method, or the like. The pattern dimension a of the fine cut pattern at this time has a limit depending on each exposure method, and is 0.5 μm for optical exposure and about 0.2 μm for electron beam exposure.

[0004]

In the conventional fine pattern forming method, there is a problem that the exposure method used has a resolution limit, and it is not possible to form a punched pattern finer than the limit.

The present invention has been made to solve the above problems, and an object of the present invention is to provide a method for forming a fine punching pattern below the resolution limit.

[0006]

A method for forming a fine pattern according to the present invention is for forming a fine pattern on a resist for pattern formation coated on a substrate, and for generating a mixture for mixing with the resist for pattern formation. A resist is applied and baked at a temperature for forming a required mixing layer, and the unmixed resist for mixing generation is removed to form a punching pattern finer than the size of the fine punching pattern.

[0007]

In the present invention, the fine pattern formed on the resist for pattern formation is coated with the resist for forming mixing which is easy to mix with the resist for pattern formation and baked to form a mixing layer, and then the mixture is mixed. By removing the mixing generation resist other than the layers, a finer pattern can be formed by the thickness of the mixing layer than the size of the fine resist removal pattern formed on the pattern forming resist, and the resolution limit can be improved.

[0008]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT An embodiment of the present invention will be described below with reference to FIG. 1A to 1E are process sectional views showing an embodiment of the fine pattern forming method of the present invention. In FIG. 1, 1 is a substrate, 2 is a pattern forming resist, 3 is a mixing generation resist which easily mixes with the pattern forming resist 2, 4 is a mixing layer, and a is formed on the pattern forming resist 2. Pattern dimensions,
“B” indicates the thickness of the mixing layer 4, and “c” indicates the fine pattern size after the mixing layer 4 is formed.

The steps of forming a fine pattern will be described below with reference to the drawings. As shown in FIG. 1A, a pattern forming resist 2, for example, PMMA (polymethylmethacrylate) is applied on a substrate 1 to a thickness of about 5000Å, and baking is performed in an oven at 180 ° C. for 30 minutes. Next, it is exposed by an electron beam exposure method or an optical exposure method and developed with an organic solvent such as methylisobutylketone to give 0.2 μm.
A fine punched pattern having a fine pattern dimension a of about m is formed (FIG. 1B). Next, a resist 2 for pattern formation and a resist 3 for mixing for generating mixing, for example, a normal photoresist dissolved in ethyl cellosolve acetate which is a solvent such as PMMA are applied (FIG. 1 (c)), Baking is performed at about 50 to 80 ° C., which is lower than the resist baking temperature, and the mixing layer 4
To a thickness of 100 to 500Å (FIG. 1 (d). Then, the mixing generation resist 3 other than the mixing layer 4 is removed with a developing solution, and as shown in FIG. 1 (e), FIG.
A fine punching pattern having a resist pattern size c which is (a-2b) compared with the pattern size a of is formed. For example, a has a pattern size of 0.2 μm and b has a size of 200 Å (0.
When the thickness is 02 μm), the final resist pattern dimension c is c = 0.2 μm−0.02 μm × 2 = 0.16.
Since it becomes μm, a fine pattern can be formed. In addition,
The thickness b of the mixing layer 4 depends on the baking temperature and time. The thickness b of the mixing layer 4 increases in proportion to the bake time until the bake time reaches a certain time (for example, 15 minutes), but when the bake time is longer than that, the increase amount decreases and the thickness b stops at a constant thickness. Also, the pattern forming resist 2
In addition to the above, a novolac-based resist may be used, and as the mixing generation resist 3, other than the above, chloromethylated polystyrene (CMS) or the like may be used.

[0010]

As described above, according to the present invention,
After forming a fine punched pattern on the pattern forming resist, a mixing generation resist that mixes with the pattern forming resist is applied and baked to form a mixing layer, and a mixing generation resist other than this mixing layer is formed. By removing the above, a punching pattern having a finer dimension than the initial fine punching pattern is formed, so that fine processing of a semiconductor device or the like can be easily performed.

[Brief description of drawings]

FIG. 1 is a process sectional view of a fine pattern forming method according to the present invention.

FIG. 2 is a process sectional view of a conventional fine pattern forming method.

[Explanation of symbols]

 1 substrate 2 pattern forming resist 3 mixing generating resist 4 mixing layer a pattern dimension b mixing layer thickness c fine pattern dimension

Claims (1)

[Claims] 1. A fine pattern is formed on a pattern forming resist applied on a substrate, and then a mixing generation resist for mixing with the pattern forming resist is applied on the entire surface of the substrate to form the pattern forming resist. A fine pattern characterized by forming a mixing layer by baking at a mixing temperature, and removing the mixing generation resist in a non-mixed portion to form a finer punch pattern than the fine punch pattern size. Forming method.