# US 5,702,975 A · Method for isolating semiconductor device

> Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt

- Number: US 5,702,975 A
- Document ID: US5702975A
- Status: Granted
- Kind: A
- Application number: 08/719,876
- Filed: 1996-09-25
- Granted: 1997-12-30
- Earliest claimed: 1995-11-08
- Assignees: Electronics and Telecommunications Research Institute
- Inventors: Hyung-Sup Yoon; Jin-Hee Lee; Chul-Sun Park; Kwang-Eui Pyun
- Web page: https://patentgrep.com/patent/US5702975A

## CPC

- H10D 30/015: {of FETs having heterojunction interface channels or heterojunction gate electrodes, e.g. HEMT}
- H10D 64/0125: {characterised by the sectional shape, e.g. T or inverted T}
- H10W 10/00: Isolation regions in semiconductor bodies between components of integrated devices
- H10W 10/01: {Manufacture or treatment}
- H10D: INORGANIC ELECTRIC SEMICONDUCTOR DEVICES
- H10W: GENERIC PACKAGES, INTERCONNECTIONS, CONNECTORS OR OTHER CONSTRUCTIONAL DETAILS OF DEVICES COVERED BY CLASS H10

## Abstract

A method for isolating a semiconductor device is disclosed including the steps of sequentially growing a plurality of material layers on a semiconductor substrate, etching the material layers down to a predetermined depth of the substrate to thereby define an active region, forming a semi-insulating film on the exposed semiconductor substrate in order to planarize the step-difference of the active region and the isolation region, and then, forming an ohmic metal layer on a space where the semi-insulating film is regrown.

## Claims

### Claim 1

A method for isolating a semiconductor device, comprising the steps of:
(a) sequentially growing a plurality of material layers on a semiconductor substrate;
(b) etching said material layers down to a predetermined depth of said substrate, to thereby define an active region using double insulating film mask comprised of a oxide and a nitride film;
(c) forming a semi-insulating film on said exposed semiconductor substrate in order to planarize the step-difference of said active region and an isolation region; and
(d) forming an ohmic metal layer on a space where said semi-insulating film is regrown.

### Claim 2 (depends on 1)

A method for isolating a semiconductor device as claimed in claim 1, wherein said semi-insulating film is formed by a metal organic chemical vapor deposition (MOCVD) method.

### Claim 3 (depends on 1)

A method for isolating a semiconductor device as claimed in claim 1, wherein said semi-insulating film is formed to such a height as the surface of said material layers.

### Claim 4 (depends on 1)

A method for fabricating a semiconductor device as claimed in claim 1, wherein said ohmic metal layer is formed higher than the surface of said semi-insulating film.

### Claim 5 (depends on 1)

A method for isolating a semiconductor device as claimed in claim 1, wherein said material layers include a buffer layer, a channel layer, a spacer layer, a schottky layer, and a highly doped N-type ohmic layer.