A novel passivation technique of GaAs power MESFETs

Abstract We have applied CF 4 plasma treatment to the GaAs surface before deposition of plasma-enhanced chemical vapour deposited (CVD) silicon nitride. X-ray photoelectron spectroscopy (XPS) shows that the CF 4 plasma treatment can remove As 2 O 3 and free As from the GaAs surface, and form a layer composed of Ga 2 O 3 and GaF 3 . The MESFET having this new passivation layer shows an increase in the gate breakdown voltage and a dramatic improvement in the surface-induced degradation.