Method for manufacturing isolation structure for LDMOS
US11127840B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Jul 3, 2018 |
| Grant date | Sep 21, 2021 |
| Priority date | — |
| Expiry date | Feb 4, 2039 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH10D62/116
- WIPO fieldSemiconductors
- WIPO sectorElectrical engineering
Abstract
Disclosed is a method for manufacturing an isolation structure for LDMOS, the method comprising: forming a first groove on the surface of a wafer; filling the first groove with silicon oxide; removing part of the surface of the silicon oxide within the first groove by means of etching; forming a silicon oxide corner structure at the corner of the top of the first groove by means of thermal oxidation; depositing a nitrogen-containing compound on the surface of the wafer to cover the surface of the silicon oxide within the first groove and the surface of the silicon oxide corner structure; dry-etching the nitrogen-containing compound to remove the nitrogen-containing compound from the surface of the silicon oxide within the first groove, and thereby forming a nitrogen-containing compound side wall residue; with the nitrogen-containing compound side wall residue as a mask, continuing to etch downwards to form a second groove; forming a silicon oxide layer on the side wall and the bottom of the second groove; removing the nitrogen-containing compound side wall residue; and filling the first groove and the second groove with silicon oxide.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.