Silicon carbide semiconductor device and a method of manufacturing the silicon carbide semiconductor device
摘要
說明書
In the n?-type drift layer 204, similarly to the first embodiment, a second n?-type layer (n?-type lifetime reduced layer) 221 is provided. Conditions of the carrier lifetimes of first to third n?-type layers 220 to 222 of the n?-type drift layer 204 are similar to those of the first to the third n?-type layers 21 to 23 in the first embodiment. In the second embodiment, the n?-type lifetime reduced layer 221 is provided at a position that is a certain distance (depth) d221 from a pn junction surface (interface) 230 between the p-type collector layer 202 and the n-type field stop layer 203, in a direction toward an emitter electrode 213. A reason for this is as follows.
The n-type field stop layer 203, to maintain the breakdown voltage of the IGBT, is provided having a doping concentration that is high as compared to the n?-type drift layer 204. When a lifetime reduced layer is present in the n-type field stop layer 203, the effect of reducing doping concentration by the vanadium element diminishes, whereby detection of the n?-type lifetime reduced layer 221 by CV measurement becomes difficult.
