Semiconductor device

摘要

A semiconductor device of the invention in the form of a superlattice-heterojunction bipolar transistor (SL-HBT) 10 incorporates a superlattice region 16 within an emitter mesa 21. The superlattice region 16 provides a non-linear response to a sufficiently high level of device current to counteract thermal runaway. This protects the device from damaging levels of current. The device 10 may be a radio-frequency SL-HBT with performance equivalent to that of a conventional heterojunction bipolar transistor. The invention may also be implemented as a semiconductor laser.