SEMICONDUCTOR DEVICE AND MANUFACTURING METHOD OF THE SAME, AND POWER CONVERSION SYSTEM

摘要

PROBLEM TO BE SOLVED: To provide a diode at low cost, which ensures voltage withstanding and excellent in cosmic ray ruggedness and which inhibits an oscillation phenomenon to achieve low noise; and provide a diode manufacturing process in less danger of line contamination.SOLUTION: A semiconductor device comprises: a p type layer 102 provided adjacent to an anode electrode 106 and an n type layer 104 which is adjacent to a cathode electrode 107 and in which a group V element diffuses; an n-drift layer 101 provided between the p type layer 102 and the n type layer 104; and an oxygen-containing n buffer layer 105 which is provided adjacent to the n type layer 104 and continuously across a region of a thickness of 30 μm and over. An n type carrier concentration of the n buffer layer 105 is set higher than an n type carrier concentration of the n-layer 101 and equal to or less than 1×10cm; and an oxygen concentration of the cathode electrode 107 in a region of 30 μm from a surface on the n type layer 104 side is set at not less than 1×10cmand not more than 1×10cm; and an oxygen concentration of the n-layer 101 adjacent to the p type layer 102 is set at less than 1×10cm.SELECTED DRAWING: Figure 1