Surface Passivation of GaAs using Chemical and Plasma Methods

TL;DR

This study explores chemical and plasma-based surface passivation techniques for GaAs, demonstrating significant reductions in leakage current and improved diode performance, with plasma nitrogenation showing particularly promising results.

Contribution

It introduces and compares chemical and plasma passivation methods for GaAs, highlighting plasma nitrogenation's effectiveness in reducing leakage current.

Findings

Plasma nitrogenation reduces reverse leakage current in GaAs diodes.

Some diodes exhibit an order of magnitude increase in current density.

Chemical passivation improves diode performance but needs long-term stability assessment.

Abstract

Passivation of the GaAs surface was attempted using aqueous P2S5-NH4OH,(NH4)2Sx and plasma nitrogenataion and hydrogenation. Results indicate that plasma nitrogenation with pretreatment of plasma hydrogenation produced consistent reduction in reverse leakage current at room-temperature for all p and n type schottky diodes. Some diodes showed an order of magnitude improvement in current density. Aqueous passivation showed similarly an improvement however, additional experimentation is required into long term stability and the arsenic-sulphur covalent bond strength.