Bipolar semiconductor device, e.g. diode, thyristor or IGBT

摘要

The device has a semiconductor body (1,2) and an emitter structure (3) provided on the semiconductor body. An insulator layer (6) is provided under the emitter structure and is provided with openings (7). The emitter structures may be surrounded by protective rings (4,5). The insulator layer is preferably made of silicone dioxide or silicone nitride and is preferably between 100 to 500 nm thick. The distance between the insulator layer and the surface of the emitter structure is preferably between 100 and 300 nm. The emitter efficiency may be adjusted by varying the size of the openings in the insulator layer. This layer may be formed by implantation or wafer bonding.