Hidden zener diode structure in configurable integrated circuit
US4979001A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Jun 30, 1989 |
| Grant date | Dec 18, 1990 |
| Priority date | — |
| Expiry date | Jun 30, 2009 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH10D62/364
Abstract
In one embodiment of the invention, a P diffused region, acting as an anode of a zener diode, is formed within an N+ sinker which is part of a vertical transistor in a configurable integrated circuit. This N+ sinker contacts an N+ buried layer or an N+ substrate and provides an exposed contact region for the transistor. Conductivity types may, of course, be opposite to those described in this embodiment. In this way, an additional zener diode is made available to a user without requiring additional die area. Additionally, since the zener diode is not formed from emitter and base regions of a bipolar transistor, the breakdown voltage of the zener diode may be set as desired. By forming a P zener diode anode in all N+ sinkers, or, conversely, forming a N zener cathode in all P+ sinkers, a large number of zener diodes may be made available to a user without adding any die area to the configurable integrated circuit.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.