Symmetrical high frequency SCR structure
US6989572B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Jul 9, 2003 |
| Grant date | Jan 24, 2006 |
| Priority date | — |
| Expiry date | Jul 21, 2023 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH01L21/76224
- WIPO fieldSemiconductors
- WIPO sectorElectrical engineering
Abstract
In one embodiment, an SCR device (41) includes a p+ wafer (417), a p− layer (416), an n+ buried layer (413) and an n− layer (414). P− wells (411,421) are formed in the n− layer (414). N+ regions (412,422) and p+ regions (415,425) are formed in the p− wells (411,421). A first ohmic contact (431) couples one n+ regions (422) to one p+ region (425). A second ohmic contact (433) couples another n+ region (412) to another p+ region (415) to provide physically and electrically symmetrical low-voltage p-n-p-n silicon controlled rectifiers. A deep isolation trench (419) surrounding the SCR device (41) and dopant concentration profiles provide a low capacitance SCR design for protecting high frequency integrated circuits from electrostatic discharges.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.