Title:
TRENCH ISOLATION STRUCTURE AND MANUFACTURING METHOD THEREFOR
Document Type and Number:
WIPO Patent Application WO/2019/007347
Kind Code:
A1
Abstract:
Disclosed is a method for manufacturing a trench isolation structure, the method comprising: forming a shallow trench, having a wider upper section and a narrower lower section, in a surface of a wafer; filling the shallow trench with silicon oxide by means of deposition; removing part of the silicon oxide by means of etching; forming a silicon oxide corner structure at a corner at the top of the shallow trench by means of thermal oxidation; depositing silicon nitride on the surface of the wafer so as to cover the surface of the silicon oxide in the shallow trench and a surface of the silicon oxide corner structure; carrying out dry etching on the silicon nitride so as to remove the silicon nitride on the surface of the silicon oxide in the shallow trench, and forming, on the surface of the silicon oxide corner structure, silicon nitride residues extending to the inside of the trench; taking the silicon nitride residues as a mask, and continuing to carry out etching downwards so as to form a deep trench; forming silicon oxide layers on a side wall and the bottom of the deep trench; depositing polycrystalline silicon in the shallow trench and the deep trench; removing the silicon nitride; and forming silicon oxide in the shallow trench so as to cover the polycrystalline silicon.
Inventors:
QI SHUKUN (CN)
Application Number:
PCT/CN2018/094369
Publication Date:
January 10, 2019
Filing Date:
July 03, 2018
Export Citation:
Assignee:
CSMC TECHNOLOGIES FAB2 CO LTD (CN)
International Classes:
H01L21/762
Foreign References:
| US20020081809A1 | 2002-06-27 | |||
| US5358891A | 1994-10-25 | |||
| CN102097358A | 2011-06-15 | |||
| US6020230A | 2000-02-01 | |||
| KR20030050199A | 2003-06-25 |
Attorney, Agent or Firm:
ADVANCE CHINA IP LAW OFFICE (CN)
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