Patent ID: 7355257

Claim:
A semiconductor superjunction device comprising: a semiconductor substrate; a drift region formed in the substrate; and a superjunction structure formed in the drift region, wherein the superjunction structure having alternately arranged n-type regions and p-type regions both layered parallel with the drift direction of carriers to allow current flow in an ON state and to deplete in an OFF state, wherein the superjunction structure further includes a first intrinsic semiconductor region between the n-type region and the p-type region, the first intrinsic semiconductor region, the n-type region, and the p-type region forming a unit, and a repetitive structure comprising a plurality of units that are repetitively arranged, and wherein the value of mobility of one of electrons in the n-type region or holes in the p-type region is equal to or less than half the value of mobility of corresponding one of electrons or holes in the first intrinsic semiconductor region.