Fast recovery diode

Abstract

The invention provides a fast recovery diode, which comprises a p-type semiconductor layer and an n-type semiconductor layer which is contacted with the p-type semiconductor layer, wherein in the transverse direction, the service life of a minority carrier in the p-type semiconductor layer is gradually prolonged and the doped concentration is gradually reduced from an outer surface of the p-type side to a metallurgical junction, and the service life of the minority carrier in the n-type semiconductor layer is gradually shortened and the doped concentration is gradually increased from the metallurgical junction to an outer surface of the n-type side. The fast recovery diode has higher forward recovery characteristics by controlling the doped concentration and the service life of the minority carrier. The invention also provides another fast recovery diode, which has higher reverse recovery characteristics by controlling the doped concentration and the service life of the minority carrier in the p-type semiconductor layer and the n-type semiconductor layer. The invention also provides another fast recovery diode, which has higher forward recovery characteristics and reverse recoverycharacteristics by controlling the doped concentration and the service life of the minority carrier in the p-type semiconductor layer and the n-type semiconductor layer.

Description

technical field [0001] The invention belongs to the technical field of semiconductor devices, in particular to fast recovery diodes. Background technique [0002] FAST RECOVERY DIODE (FRD, FAST RECOVERY DIODE) is a new generation of new-generation power semiconductor devices made of epitaxial silicon single wafers and manufactured by COMS technology. It has high frequency, high voltage, high current, low loss and no electromagnetic interference. Etc. FRD can be used alone as an output rectifier diode, clamping diode, absorbing diode, etc., or it can be used as a freewheeling diode in conjunction with an insulated gate bipolar transistor (IGBT, Insulated Gate Bipolar Transistor). Fast recovery diode single tube and modules and modules combined with IGBT are widely used in motor frequency conversion speed regulation, electric welding machines, various switching power supplies, inverters, electrostatic induction and other heating industries, medicine and aerospace fields. [...

AI Technical Summary

Problems solved by technology

[0004] The present invention provides a fast recovery diode in order to solve the technical problem that the forward recovery characteristics and reverse recovery characteristics of the fast recovery diode (FRD) in the prior art cannot meet the requirements, and the fast recovery diode provided by the present invention includes a better A fast recovery diode with forward recovery characteristics, a fast recovery diode with good reverse recovery characteristics, and a fast recovery diode with good forward and reverse recovery characteristics at the same time

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