Patent ID: 7622756

Claim:
A semiconductor device including a plurality of unit transistors, comprising: a plurality of first transistor formation regions each having a first number of said unit transistors; and a second transistor formation region having a second number of said unit transistors, wherein said second transistor formation region is located between said first transistor formation regions, and wherein said first number is larger than said second number, wherein each of said unit transistors is a bipolar transistor having a collector electrode, a base electrode, and an emitter electrode, and wherein said unit transistors have said respective collector electrodes electrically connected to each other, said respective base electrodes electrically connected to each other, and said respective emitter electrodes electrically connected to each other, and wherein said unit transistors are formed over a substrate made of a compound, wherein a hole providing connection between each of said emitter electrodes and an electrode formed on a back surface of said substrate is located substantially in the middle of an arrangement of said first number of said unit transistors and substantially in the middle of an arrangement of said second number of said unit transistors.