SEMICONDUCTOR DEVICE WITH AUXILIARY STRUCTURE INCLUDING TIEFPEGELDOTIERSTOFFEN

A semiconductor device (500) comprises transistor cells (TC), which are formed along a first surface (101) on a front side of a semiconductor body (100) in a transistor cell region (610). A drift zone structure (120) first pn junctions (PN1) with body zones (115) of the transistor cells (TC). An auxiliary structure (132) between the drift zone structure (120) and a second surface (102) on a rear side of the semiconductor body (100) comprises a first portion (132a) containing Tiefpegeldotierstoffe which require at least 150 meV to ionize. A collector structure (138) is directly adjacent to the auxiliary structure (132). An injection efficiency of minority carriers from the collector structure (138) in the drift zone structure (120) along changing a direction parallel to the first surface (101) at least in the transistor cell region (610).