Improvement of off-state breakdown voltage in power GaAs MESFETs based on an accurate simulation scheme

A realistic simulation scheme for improving off-state breakdown voltage (BV/sub gd/) in power GaAs MESFETs has been developed. In this scheme, impact ionization, tunneling, and surface charge dynamics are all considered. The simulation successfully describes experimentally observed breakdown behavior. Using the simulation results, we have developed an FET with a neutralized p-buffer layer that improves BV/sub gd/ by at least 10 V higher than that of conventional FETs.