US Patent 7135747 Semiconductor devices having thermal spacers

A high power, high frequency semiconductor device has a plurality of unit cells connected in parallel. The unit cells each having a controlling electrode and first and second controlled electrodes. A thermal spacer divides at least one of the unit cells into a first active portion and a second active portion, spaced apart from the first potion by the thermal spacer. The controlling electrode and the first and second controlled electrodes of the unit cell cross over the first thermal spacer.