Patent ID: 7633123

Claim:
A semiconductor device comprising: a pair of main electrodes for conducting a carrier having a first conductive type therebetween; a plurality of first regions having the first conductive type and extending along with an extending direction, which is parallel to a direction connecting between the pair of main electrodes; and a plurality of second regions having a second conductive type and extending along with the extending direction, wherein the first regions and the second regions are alternately repeated along with a repeat direction perpendicular to the extending direction so that each first region is sandwiched between two of the second regions and each second region is sandwiched between two of the first regions, the first region has a first impurity concentration and a first width, which is measured along with the repeat direction, the second region has a second impurity concentration and a second width, which is measured along with the repeat direction, a product of the first impurity concentration and the first width is equal to a product of the second impurity concentration and the second width, the first width is equal to or smaller than 4.5 μm, the first impurity concentration is lower than a predetermined impurity concentration satisfying a RESURF condition, the device has an on-state resistance at 27° C. defined as R 1 and another on-state resistance at 150° C. defined as R 2 , and a ratio between the on-state resistance of R 2 and the on-state resistance of R 1 is smaller than 1.8.