New high power planar gate GaAs MESFETs with improved gate-drain breakdown voltage

The authors present a new approach to power GaAs MESFETs with planar gate structures, based on the MBE growth technique on an undoped surface GaAs layer on an ion-implanted channel layer. This undoped GaAs layer increases the gate-drain breakdown voltage and serves as both an ideal passivation layer and an ideal annealing cap of ion implanted channels. To realise a good surface condition before MBE growth, the UV-ozone surface treatment is introduced. This new simple structure offers high performance power GaAs MESFETs