# US 5,702,867 A · Method for forming fine pattern in semiconductor device

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- Number: US 5,702,867 A
- Document ID: US5702867A
- Status: Granted
- Kind: A
- Application number: 08/294,539
- Filed: 1994-08-23
- Granted: 1997-12-30
- Earliest claimed: 1993-08-23
- Assignees: Hyundai Electronics Industries Co., Ltd.
- Inventors: Myung Seon Kim
- Web page: https://patentgrep.com/patent/US5702867A

## CPC

- G03F 7/265: {Selective reaction with inorganic or organometallic reagents after image-wise exposure, e.g. silylation}
- H10P 50/287: {by chemical means}
- H10P 76/2041: {Photolithographic processes}
- H10P 14/6922: {the material containing Si, O and at least one of H, N, C, F or other non-metal elements, e.g. SiOC, SiOC:H or SiONC}
- Y10S 438/948: Radiation resist
- G03F: PHOTOMECHANICAL PRODUCTION OF TEXTURED OR PATTERNED SURFACES, e.g. FOR PRINTING, FOR PROCESSING OF SEMICONDUCTOR DEVICES; MATERIALS THEREFOR; ORIGINALS THEREFOR; APPARATUS SPECIALLY ADAPTED THEREFOR; (phototypographic composing devices B41B; photosensitive materials or processes for photographic purposes G03C; electrophotography, sensitive layers or processes therefor G03G)
- H10P: GENERIC PROCESSES OR APPARATUS FOR THE MANUFACTURE OR TREATMENT OF DEVICES COVERED BY CLASS H10
- Y10S: TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS

## Abstract

A method for forming fine pattern in a semiconductor device. It comprises the steps of: providing an objective material layer to be patterned covering a photosensitive film atop a semiconductor substrate; selectively exposing the surface of the photosensitive film, to determine a region to be patterned, in the surface of the photosensitive film; diffusing silicon into the surface of the photosensitive film by use of hexamethyl disilazane (HMDS) or tetramethyl disilazane (TMDS), to form a uniformly thin, silylated photosensitive material film at an unexposed surface of the photosensitive film and a thick, silylated photosensitive material film having a shape of convex lens at the exposed surface of the photosensitive film; etching the silylated photosensitive material layer and the photosensitive film with plasma containing NF.sub.3 /O.sub.2, in such a predetermined thickness as to remove the edge of the silylated photosensitive material having a shape of convex lens, to form a silylated photosensitive material pattern which finely determines the region to be patterned; and subjecting the photosensitive film exposed by the silylated photosensitive material pattern to anisotropic etch with oxygen-based plasma, to selectively expose the objective material layer to be patterned. Keeping the CD of the photosensitive film pattern constant, it can provide a clean and smooth surface.

## Claims

### Claim 1

A method for forming fine pattern in a semiconductor device, comprising the steps of:
providing an objective material layer to be patterned atop a semiconductor substrate;
coating a photosensitive film on the objective material layer;
selectively exposing the surface of the photosensitive film to determine a region to be patterned in the surface of the photosensitive film;
diffusing silicon into the surface of the photosensitive film by use of hexamethyl disilazane (HMDS) or tetramethyl disilazane (TMDS), to form a uniformly thin, silylated photosensitive material film at an unexposed surface of the photosensitive film and a thick, silylated photosensitive material film having a shape of convex lens at the exposed surface of the photosensitive film;
etching the silylated photosensitive material layer and the photosensitive film with plasma containing NF.sub.3 and O.sub.2, to such a predetermined thickness as to remove the edge of the silylated photosensitive material having a shape of convex lens, to form a silylated photosensitive material pattern which finely determines the region to be patterned; and
subjecting the photosensitive film exposed by the silylated photosensitive material pattern to anisotropic etch with oxygen-based plasma, to selectively expose the objective material layer to be patterned.

### Claim 2 (depends on 1)

A method as set forth as claim 1, wherein the NF.sub.3 constitutes about 30 to 80% of said plasma containing NF.sub.3 and O.sub.2.

### Claim 3 (depends on 1)

A method as set forth as claim 1, wherein said oxygen-based plasma further comprises argon, nitrogen or helium.