Field dependence of the E1′ and M3′ electron traps in inductively coupled Ar plasma treated n-Gallium Arsenide

Abstract

Inductively coupled Ar plasma etching of n-type (Si doped) Gallium Arsenide (GaAs) introduces several electron traps, Ec – 0.04 eV (labelled E1′), Ec – 0.19 eV, Ec – 0.31 eV, Ec – 0.53 eV, and Ec – 0.61 eV (behaving like the well documented M3 and labelled M3′ in this study), of which the metastable defects Ec – 0.04 eV (E1′), and Ec – 0.07 eV are novel. Furthermore, E1′ and M3′ exhibit strong field enhanced carrier emission. Double-correlation deep level transient spectroscopy was used to investigate the field dependent emission behaviour of these two defects. It is shown that for both traps, the observed enhanced emission is due to phonon assisted tunnelling. The latter observation is contrary to the literature reports suggesting that enhanced carrier emission for M3 occurs via the Poole-Frenkel mechanism.