Patent ID: 6992351

Claim:
A semiconductor device comprising: a semiconductor substrate; and a first transistor and a second transistor formed on said semiconductor substrate, each of the first and second transistors having a first main electrode region formed on one surface side of said substrate, a second main electrode region formed on the other surface side of said substrate, and a gate electrode for control of a current flowable between said first main electrode region and said second main electrode region, while letting said second main electrode region be owned in common by said first and second transistors, wherein said first main electrode region of said first transistor is formed to be divided into a plurality of first isolated island regions on the one surface side of said semiconductor substrate, said first main electrode region of said second transistor is formed on the one surface side of said semiconductor substrate and is divided into a plurality of second isolated island regions as laid out adjacent to at least part of said plurality of first isolated island regions, at a portion whereat neighboring ones of said first isolated island regions face each other, the neighboring first isolated island regions are combined together into a unified first isolated island region, and in this unified first isolated island region said first main electrode region of said first transistor is integrally formed, at a portion whereat neighboring ones of said second isolated island regions face each other, the neighboring second isolated island regions are combined together into a unified second isolated island region, and in this united second isolated island region said second main electrode region is integrally formed, said first isolated island regions and said second isolated island regions are organized into at least first groups being alternately placed while letting a contour extending in a first direction be an adjacent portion and second groups being alternately placed while letting a contour extending in a second direction other than said first direction be an adjacent portion, one of the first isolated island regions of said first groups and its neighboring one of the first isolated island regions of said second groups are combined together into said unified first isolated island region, and one of the second isolated island regions of said first groups and its neighboring one of the second isolated island regions of said second groups are combined together into said unified second isolated island region.