ABSTRACT
The preparation of GaN HEMTs are largely similar to that of GaAs HEMTs, including such major processes as active region isolation, preparation of ohmic contact for source/drain electrodes, preparation of Schottky contact for gate electrode, surface passivation, and metal interconnecting. The performance of the HEMT is influenced by each process step as well as by cleaning and photolithograph. Each single step must be fully optimized to form a process flow both reasonable and stable for the prepared HEMT die to operate normally and demonstrate high performance.
