Patent ID: 8378427
Filing Date: 2013-02-19
Classification: H01L

Abstract:
1. An IGBT made on a semiconductor substrate of a first conductivity type having two main surfaces, comprising at least a cell of a metal-insulator-semiconductor field effect transistor, MISFET, of first conductivity type and at least a cell of a bipolar junction transistor, BJT, of a second conductivity type, wherein said cell of MISFET of said first conductivity type has at least one cell of source-body region of semiconductor of second conductivity type underneath the first main surface and at least one source region of semiconductor of said first conductivity type in said source-body region, and a part of said source-body region and a part of said source region are connected by a conductor as a source electrode of said MISFET; an insulator layer covering on the surface of a part of said source region, a part of said source-body region and a part of said substrate, and a conductor covering on said insulator layer as the gate electrode of said MISFET; said cell of BJT of said second conductivity type has a base region in said substrate, at least one emitter region being a semiconductor region of second conductivity type in the second main surface and at least one collector region; wherein said emitter region is adjacent at least a base region, both said emitter region and said base region have their own electrodes as emitter and base on said second main surface, respectively, said collector region is said source-body region of said MISFET, a collector of BJT is said source electrode of said MISFET; said IGBT has an edge termination region at first main surface separating entire source-body regions of said cell(s) of MISFET of said IGBT from a neutral base region, said neutral base region keeps neutral rather than depleted even under a maximum reverse bias voltage applied across said emitter and said collector; at least a portion of said edge termination region has a section of largest voltage contacting directly to said source-body region of said MISFET, a section of transit region contacting directly to said section of largest voltage on the one end and contacting directly or through a field-stop region of a heavily doped semiconductor of first conductivity type to said neutral base region on the other end; said section of transit region has at least a bottom layer of second conductivity type starting from said section of largest voltage to a place with a distance to said neutral base region, wherein said distance is smaller than a distance from said one end to said other end; said voltage is with respect to said neutral base region, and said largest voltage is a negative value when said semiconductor of first conductivity type is n-type, said largest voltage is a positive value when said semiconductor of first conductivity type is p-type; a low-voltage circuit region is located in said neutral base region; said low-voltage circuit region has at least two semiconductor regions, each lead out an electrode as two output terminals of said low-voltage circuit region, and said two terminals are each connected to each said emitter and said base of the second main surface of said IGBT through outer connections; said low-voltage circuit region has at least one electrode terminal as control terminal(s), and a voltage drop across two output terminals of said low-voltage circuit is controlled by applying a voltage across said control terminal(s) and said neutral base region.