Plasma-induced damage of GaAs <i>pn</i>-junction diodes using electron cyclotron resonance generated Cl2/Ar, BCl3/Ar, Cl2/BCl3/Ar, and SiCl4/Ar plasmas

Abstract

Plasma-induced etch damage often degrades the electrical and optical performance of III–V high-density integrated circuits and photonic devices. We have investigated the etch-induced damage of electron cyclotron resonance (ECR) generated plasmas on the electrical performance of mesa-isolated GaAs pn-junction diodes. Cl2/Ar, BCl3/Ar, Cl2/BCl3/Ar, and SiCl4/Ar ECR plasmas at ion energies ranging from 10 to 200 eV were studied. Diodes fabricated under low dc-bias (≤100 V) etch conditions yielded low reverse-bias currents which were comparable to wet-chemical-etched devices. As the dc bias was increased, the diodes showed significantly higher reverse-bias currents indicating plasma-induced sidewall damage of the pn-junction. Variations in diode reverse-bias leakage currents are reported as a function of plasma parameters and chemistries.