INSULATED GATE BIPOLAR TRANSISTOR

摘要

Disclosed is an IGBT (insulated gate bipolar transistor) (1) which is capable of reducing the on-resistance by decreasing the channel mobility. The IGBT (1) comprises: an n-type substrate (11) that is composed of SiC and has a main surface (11A) having an off angle with respect to the {0001} plane direction of not less than 50° but not more than 65°; a p-type withstand voltage maintaining layer (13) that is composed of SiC and formed on the main surface (11A) of the substrate (11); an n-type well region (14) that is so formed as to contain a second main surface (13B) of the withstand voltage maintaining layer (13); an emitter region (15) that is so formed within the well region (14) as to contain the second main surface (13B) and contains a p-type impurity at a higher concentration than the withstand voltage maintaining layer (13); a gate oxide film (17) that is formed on the withstand voltage maintaining layer (13); and a gate electrode (19) that is formed on the gate oxide film (17). In the IGBT (1), a high nitrogen concentration region (22) having a higher nitrogen concentration than the well region (14) and the gate oxide film (17) is formed in a region that contains the interface between the well region (14) and the gate oxide film (17).