Insulated gate bipolar transistor
US5719412A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Oct 17, 1995 |
| Grant date | Feb 17, 1998 |
| Priority date | — |
| Expiry date | Oct 17, 2015 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH10D62/106
Abstract
The insulated gate bipolar transistor (IGBT) integrates the anti-excess voltage protection function and a drain voltage fixing function. When a voltage is applied across the drain electrode and the source electrode of the IGBT, a depletion zone propagates from a p-n junction between a p base layer and a n.sup.- drain layer toward inside of the n.sup.- drain layer. A critical electric field is also established, causing generation of a great number of electron-hole pairs due to impact ionization of carriers in or near the n.sup.- drain layer. Conduction exist between the drain electrode and the source electrode, at an applied voltage lower than a drain-source voltage at which the depletion region reaches a p.sup.+ drain layer through the n.sup.- drain layer, the applied voltage being equal to or lower than a critical voltage that causes generation of a great number of electron-hole pairs due to impact ionization of carriers in or near the n.sup.- drain layer below a p-n junction between a p-type guard ring and the n.sup.- drain layer.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.