Gallium nitride-new material for microwave and optoelectronics

The first GaAs diodes and field effect transistors (FETs) and the first GaAs/AlGaAs heterojunction FETs (HFETs) and heterojunction bipolar transistors (HBTs), were followed soon by the devices fabricated utilising the InP based materials, which enabled one to achieve a much higher frequency of operation, speed and much lower noise. Recent achievements in diode and HFET technology utilising GaN based materials proved their potential as power devices, UV photodetectors and in high temperature electronics. In this paper after a brief review of GaN properties as compared with other semiconductors, its technology is briefly described and then the state of the art of GaN based devices is given and its further potential for development shown.