Reverse conducting IGBT

Abstract

The invention discloses a reverse conducting IGBT. A forming area of the IGBT and a forming area of an FRD are adjacent to each other and are isolated from each other in the transverse direction. A drift region and a field stop layer are formed in the forming region of the IGBT and the FRD; in the formation region of the IGBT, a collector region is formed on the back surface of the field stop layer. In the formation region of the FRD, a first electrode region is formed on the back surface of the field stop layer. A deep trench through the drift region is formed in the formation region of the FRD. A first epitaxial layer and a second epitaxial layer which are opposite in doping type are formed on the surfaces of the deep groove and the drift region, and the deep groove is further filled with a third insulating medium layer. And second conductive type doped well regions are formed on the surfaces of the first epitaxial layer and the second epitaxial layer on the drift region. The IGBT and the FRD can be well isolated, flyback of the IGBT can be restrained, the performance of the FRD can be locally optimized at the same time, the injection efficiency of the FRD can be improved, the minority carrier lifetime of the FRD can be controlled, the structure of a terminal area can be optimized, and the area can be saved.

Description

technical field [0001] The invention relates to a semiconductor integrated circuit, in particular to a reverse conducting (Reverse Conducting, RC) IGBT. Background technique [0002] While the reverse conduction IGBT has many advantages, there are also some problems, the most important of which are the voltage snapback phenomenon (snapback) during the turn-on process of the IGBT and the introduction of The control of the minority carrier lifetime will cause the increase of the saturation voltage (Vcesat) between the collector and emitter of the IGBT: when the RC-IGBT is turned on, the electron current will flow out from the cathode where the FRD is located, and the IGBT collector junction cannot form enough bias initially. When the electron current is large enough to open the IGBT collection junction, a large number of holes will mainly cause the resistance of the drift region to decrease suddenly, thus forming a retrace phenomenon. So how to prevent the flow of electron cu...

AI Technical Summary

Problems solved by technology

At the same time, the global lifetime control in order to reduce the FRD reverse recovery charge will inevitably increase the saturation voltage of the IGBT

Moreover, FRD needs a certain area to reduce Vf, which also means that IGBT needs to lose these areas

[0003] Generally speaking, its problem is mainly that the parameters in the optimization performance of IGBT and FRD conflict with each other, and it is difficult to balance

Images