Method for fabrication of semiconductor device
US5480832A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Oct 21, 1993 |
| Grant date | Jan 2, 1996 |
| Priority date | — |
| Expiry date | Oct 21, 2013 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY10S438/977
- WIPO fieldSemiconductors
- WIPO sectorElectrical engineering
Abstract
An object of the invention is to prevent the occurrence of breaking or short-circuiting of a wiring caused by a difference in level in an isolation trench area formed in an SOI substrate. An oxide film is formed for a pad on the main surface of an SOI layer formed on an insulating substrate, a silicon nitride film are formed and an SiO.sub.2 film in order, then an isolation trench reaching to the insulating substrate is by means of an R.I.E process using the SiO.sub.2 film as a mask. Thereafter an insulating film is formed on an inside wall of the isolation trench by means of thermal oxidation, the isolation trench is filled with polysilicon, the polysilicon is etched back while controlling the etching so that the top of the polysilicon in the isolation trench remains higher than the top of the silicon nitride film, an extra part of the polysilicon deposited on the surface of the substrate, is removed and then the SiO.sub.2 film used as a mask when forming the isolation trench is etched off using the polysilicon in the isolation trench and the silicon nitride film as an etching stopper. In this manner, since the SiO.sub.2 film used as a mask is etched off after filling the isolatio…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.