Improvements in GaAs/plasma-deposited silicon nitride interface quality by predeposition GaAs surface treatment and postdeposition annealing

Abstract

Substantial improvements in the electrical properties of interfaces between n-type GaAs and Si3N4 formed by plasma-enhanced CVD have been obtained by in situ substrate surface treatment with a hydrogen plasma and postdeposition annealing. For samples with surface treatment and deposition performed at 300 °C, annealing at 600° for 30 min in N2 produced a dramatic reduction of capacitance frequency dispersion. Capacitance and conductance data indicate a major reduction of surface state density. Low-frequency C–V on an illuminated sample show evidence of surface inversion. AES composition profiles are presented as evidence that the hydrogen plasma treatment reduces native oxide on the GaAs.