Metal crossover in high voltage IC with graduated doping control
US5426325A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Aug 4, 1993 |
| Grant date | Jun 20, 1995 |
| Priority date | — |
| Expiry date | Aug 4, 2013 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH10D62/105
- WIPO fieldSemiconductors
- WIPO sectorElectrical engineering
Abstract
Non-uniformly doped regions are formed adjacent to semiconductor junctions which underlie high voltage crossovers. The non-uniformly doped regions prevent junction breakdown caused by strong electric fields. The voltage drop between a crossover and an element of an integrated circuit is spread over the non-uniformly doped region, to lessen the voltage drop between the crossover and the junction and lessen the electric field at the junction. Dopant concentrations in the non-uniformly doped region may be selected to minimize use of silicon real estate. In some embodiments, a graded dopant concentration is lightest near the junction and increases toward a circuit element being protected.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.