Method of forming semiconductor device
US9564520B1 · kind B1 · utility
Assignee
Inventor
Key dates
| Filing date | Jun 30, 2016 |
| Grant date | Feb 7, 2017 |
| Priority date | — |
| Expiry date | Jun 30, 2036 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH10B43/35
- WIPO fieldSemiconductors
- WIPO sectorElectrical engineering
Abstract
A method of forming a semiconductor device is disclosed. A sacrificial oxide layer is formed on a substrate having first and second areas. Using a photoresist mask exposing the first area and covering the second area as a mask layer, by a wet etching process, the sacrificial oxide layer in the first area and an edge portion of the sacrificial oxide layer in the second area are simultaneously removed, wherein the sacrificial oxide layer remained in the second area has a sidewall with a slope smaller than 40 degrees. An oxide-nitride-oxide (ONO) layer is formed over the first and second areas. The sacrificial oxide layer and the ONO layer formed thereon in the second area are removed, so that the ONO layer remained in the first area forms a first gate insulating layer in the first area. A second gate insulating layer is formed in the second area.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.