Patent ID: 8017974
Filing Date: 2011-09-13
Classification: H01L,Y10S

Abstract:
1. A semiconductor device comprising: a semiconductor element region provided at a front surface of a semiconductor substrate of a first conduction type; a collector layer of a second conduction type and a buffer layer of said first conduction type provided in said semiconductor substrate in a direction of a depth of said semiconductor substrate as seen from a back surface of said semiconductor substrate; and a donor layer including a defect layer in said semiconductor substrate at a region located at a depth of approximately 32 μm as measured from the back surface of said semiconductor substrate, wherein said collector layer includes a region of an impurity of said second conduction type in said semiconductor substrate at a region located from the back surface of said semiconductor substrate to a depth of approximately 0.5 μm, said impurity of said second conduction type being injected in an amount of at most 1×10 said buffer layer contains an impurity of said first conduction type in said semiconductor substrate at a region located at a depth from approximately 0.5 μm to approximately 20 μm as measured from the back surface of said semiconductor substrate, with said impurity of said first conduction type having a concentration with a maximum value of approximately 3×10 said donor layer includes a defect layer formed with a dose of protons of at most 1×10 said amount of said impurity injected in said collector layer and said dose of protons forming said defect layer reducing snapback voltage at low temperatures to be approximately at most 2V.