Patent ID: 6777747
Filing Date: 2004-08-17
Classification: H01L

Abstract:
An IGBT with improved Self-Clamped Inductive Switching (SCIS) energy dissipation, comprising:a semiconductor substrate having first and second surfaces spaced from each other; a source region in the first surface, the source region heavily doped with a dopant of a first polarity; a base region in the first surface, the base region surrounding the source region and doped with a dopant of a second, opposite polarity; a drift region of the same polarity doping as the source region, the drift region extending from a first end at the first surface to a second end spaced from the first surface in a direction toward the second surface; a buffer region disposed adjacent the second end of the drift region and having the same polarity as the source region; and a collector region in the second surface and heavily doped with a dopant of the second polarity, wherein the buffer region doping concentration has a peak doping concentration at a location proximate the drift region greater than injected hole carrier concentration in the buffer region at the drift end of the buffer region.