Semiconductor device having element isolation structure
US6635945B1 · kind B1 · utility
Assignee
Inventors
Key dates
| Filing date | May 30, 2000 |
| Grant date | Oct 21, 2003 |
| Priority date | — |
| Expiry date | May 30, 2020 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH10D62/117
- WIPO fieldSemiconductors
- WIPO sectorElectrical engineering
Abstract
A semiconductor device and process of forming the device are described. The process includes forming a pad oxide film on the circuit-forming side of a semiconductor substrate; forming an oxidation prevention film on the pad oxide film; removing the oxidation prevention film and the pad oxide film at a desired position, thereby exposing the surface of the semiconductor substrate; horizontally recessing the pad oxide film; etching the exposed surface of the semiconductor substrate by isotropic etching; forming a trench to a desired depth, using the oxidation prevention film as a mask; horizontally recessing the pad oxide film; and oxidizing the trench formed in the semiconductor substrate. The produced device has round upper trench edges obtained by conducting isotropic etching of the exposed surface of the semiconductor substrate and horizontally recessing of the pad oxide film before the oxidation of the trench, whereby only one oxidation step is required.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.