Patent ID: 7880171
Filing Date: 2011-02-01
Classification: C30B,H01L

Abstract:
1. A bipolar semiconductor device which conducts current between a cathode and an anode on respective opposite ends of the device and in which stacking faults are segregated from regions of the device that support the growth of stacking faults under forward bias operation, the device comprising: an n− type voltage blocking drift region between the anode and the cathode, said drift region having a thickness determined by the maximum reverse bias to be applied to the anode; an n− type silicon carbide epitaxial terminating layer positioned between the cathode and said drift region for minimizing the lifetime of p− type minority carriers conducted from the anode to the cathode through said n− type silicon carbide epitaxial terminating layer; a p− type silicon carbide epitaxial terminating layer positioned between the anode and said drift region for minimizing the lifetime of n− type minority carriers conducted from the cathode to the anode through said p− type silicon carbide epitaxial terminating layer; wherein said drift region is between and directly contacting both of said terminating layers; wherein said drift region has doping concentration that is substantially uniform throughout the drift region and lower than the doping concentration of each of the n− type silicon carbide epitaxial terminating layer and the p− type silicon carbide epitaxial terminating layer; and wherein each terminating layer has a thickness that is greater than the respective minority carrier diffusion length in that respective terminating layer.