Schottky diode characteristics and deep levels on hydrogenated n-type GaAs

Abstract

Schottky diode characteristics and deep levels of Si-doped n-type GaAs after hydrogen plasma exposure have been investigated as a function of substrate temperature during hydrogenation. The barrier height and reverse breakdown voltage of Au Schottky diodes on Si-doped GaAs increased during hydrogen plasma exposure. The ideality factor of the hydrogenated samples was lowered to 1.11 at substrate temperatures between 150 and 250 degrees C, and deep levels in these samples were effectively passivated at these temperatures. These properties of n-GaAs can be related to hydrogen redistribution in an electrically passivated surface layer. Good diode characteristics and the most effective passivation of deep levels in GaAs could be achieved at a substrate temperature of about 200 degrees C and a power density of 0.06 W cm-2.