Integrated gate bipolar transistor and method of manufacturing the same
US6482701B1 · kind B1 · utility
Assignee
Inventors
Key dates
| Filing date | Aug 2, 2000 |
| Grant date | Nov 19, 2002 |
| Priority date | — |
| Expiry date | Aug 2, 2020 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH01L21/3065
- WIPO fieldSemiconductors
- WIPO sectorElectrical engineering
Abstract
A method of manufacturing a trench gate type IGBT element, which can sufficiently round off a corner at a bottom of a trench with restricting silicon from being excessively etched. A trench is formed at a surface of a P+-type monocrystalline silicon substrate by conducting an anisotropic etching (STEP 1). A corner portion at a bottom of the trench is formed to a concave shape surface by conducting a concave etching (STEP 2). The concave etching etches the silicon substrate so that a diameter of the trench is gradually reduced as the etching advances. After that, the corner portion at a bottom of the trench is rounded off by conducting an isotropic etching (STEP 3). Since the corner portion is chamfered, a radius of curvature of the corner portion of the bottom of the trench can be increased even if an amount of the etching using the isotropic etching in the STEP 3 is small.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.