Abstract

The effects of H2 and N2 in-situ plasma treatments prior to the deposition of Schottky contacts or SiO2 passivation on GaAs have been studied, showing a large dependance of the electrical properties on the cleaning procedure. For Ti/Pt and Al diodes, degraded rectifying characteristics result after room-temperature H2 treatments, while diode ideality factors as low as 1.01 were achieved in the temperature range 160-240°C. An increase in the barrier height was also observed with increasing substrate temperature during the plasma treatments, in correlation with H indiffusion in GaAs. *IV values of refractory WNX diodes were enhanced by H2 treatments, up to 0.78 V after 800°C anneals. Improved C-V characteristics of MOS capacitors were found after H2 plasma and a thin Si layer deposition, after successive anneals at 600 and 400°C.