Schottky diodes on hydrogen plasma treated n-GaAs surfaces

The characteristics of Schottky diodes on n-GaAs fabricated after an in situ low-pressure rf H2 plasma treatment have been investigated as a function of the substrate temperature during the plasma treatment. Degraded rectifying characteristics result after room-temperature treatments, while diodes with ideality factor as low as 1.01 were achieved in the temperature range 160-240 °C. An increase in barrier height was also observed with increasing substrate temperature during plasma treatment. The contact properties are correlated to H diffusion in a surface layer of GaAs, which passivates the dopant atoms and defect sites.