The Link between Gallium Vacancies and Plasma Damage to n-Type GaN

Abstract

Two differing trends of plasma damage in n-type GaN have been observed. The two modes of etching characteristics were attributed to the presence of Ga vacancies in the material. The resistivity of GaN with Ga vacancies increases upon plasma exposure through electrical compensation by the formation of deep acceptor states as a result of vacancy-complex formation. GaN samples free of Ga vacancies show a reduction of resistivity as N vacancies are produced through interactions with the plasma. These results correlate well with the photoluminescence spectra, where a significant yellow-band emission was detected from the samples with a high concentration of Ga vacancies.