Single mask trench fred with enlarged Schottky area
US6656843B2 · kind B2 · utility
Assignee
Inventor
Key dates
| Filing date | Apr 25, 2002 |
| Grant date | Dec 2, 2003 |
| Priority date | — |
| Expiry date | May 15, 2022 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH10D8/60
- WIPO fieldSemiconductors
- WIPO sectorElectrical engineering
Abstract
A single mask process is described for making a trench type fast recovery process. The single mask defines slots in a photoresist for locally removing strips of nitride and oxide from atop silicon and for subsequently etching trenches in the silicon. A boron implant is carried out in the bottoms of the trenches to form local P/N junctions. The oxide beneath the nitride is then fully stripped in the active area and only partly stripped in the termination area in which the trenches are wider spaced than in the active area. Aluminum is then deposited atop the active area and in the trenches, but is blocked from contact with silicon in the active area by the remaining nitride layer.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.