Manufacturing method of semiconductor device
US6448139B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Jun 7, 2001 |
| Grant date | Sep 10, 2002 |
| Priority date | — |
| Expiry date | Jun 7, 2021 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH10D64/513
Abstract
A semiconductor substrate has a trench for forming a gate insulation film and a gate electrode therein, or an insulated isolation isolating a semiconductor element like a transistor from other elements. The trench is formed by anisotropic dry etching. After that, a shape of the trench is improved so that a bottom portion and an opening portion are rounded or tapered by a wet process using a mixed solution containing hydrofluoric acid and nitric acid. By modifying the shape of the trench, electrical characteristics of the trench are improved. For example, an oxide film formed in the trench has high quality, whereby a gate withstanding voltage is improved.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.