Characterization of ion beam etching induced defects in GaAs

Abstract

Ion beam etching (IBE) of GaAs was carried out at an energy of 1 keV using Ar and CCl2F2 as a source gas and defect center induced by IBE was investigated by means of deep level transient spectroscopy and carrier profile measurements. From DLTS measurements, five different defect centers (electron traps) were resolved. They were distributed far beyond the ion range and showed different depth profiles. The deep distribution of IBE induced defects was also confirmed from the carrier profile measurement. Annealing at 500 °C was effective to reduce the observed defect centers but defect centers with a concentration between 1×1015 and 5×1016/cm3 still remained.