INSULATED GATE BIPOLAR TRANSISTOR WITH MESA SECTIONS BETWEEN CELL TRENCH STRUCTURES AND METHOD OF MANUFACTURING

摘要

An IGBT includes a mesa section which extends from the first surface of a semiconductor part to a layer section of the semiconductor part between two cell trench structures. A source region is electrically connected to an emitter electrode and is formed in a mesa region. A doped region is separated from the source region by the body region of a complementary conductivity type and includes a first part having a first average impurity concentration and a second part having a second average impurity concentration which is ten times (or more) higher than the first average pure impurity concentration. In the mesa section, the first part extends from the body region to the layer section. The second part of the doped region makes the mesa region virtually narrow in the normal on-state of the IGBT.