ESD protection circuit
US8217461B1 · kind B1 · utility
Assignee
Inventors
Key dates
| Filing date | Jul 9, 2010 |
| Grant date | Jul 10, 2012 |
| Priority date | — |
| Expiry date | Jan 13, 2031 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH01L2924/0002
- WIPO fieldSemiconductors
- WIPO sectorElectrical engineering
Abstract
A multi-fingered gate transistor is disclosed that is formed in a substrate of one conductivity type overlying a well of a second conductivity type. Ohmic contact to the well is made by an implanted region of the second conductivity type that circumscribes the multi-fingered gate transistor. Ohmic contact to the substrate is made by four taps located on four sides of the multi-fingered gate structure between the gate structure and the well contact. Floating wells are located on opposite sides of the gate structure between two of the substrate taps and the ends of the gates to isolate these substrate taps and force current flow in the substrate under the multifingered gate transistor to be substantially perpendicular to the direction in which the gate fingers extend. This increases the potential difference between these substrate regions and adjacent source regions in the multi-fingered gate transistor, thereby aiding the triggering of the parasitic bipolar transistors under adjacent gate fingers into a high current state. This also reduces the differences among the potentials in the substrate under the different source regions and thus improves the uniformity of turn-on of the para…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.