In this study, various surface cleaning techniques for the removal of contaminants from GaN were investigated. Auger
electron spectroscopy (AES) analysis was used to monitor the presence of surface contaminants and atomic force microscopy
(AFM) was used to monitor surface roughness. AES analysis showed that KOH was effective in removing carbon (C).
Comparing the topographies of GaN surfaces cleaned in HCl, KOH and (NH4)2S in aqueous solutions; it has been found that
surfaces cleaned in (NH4)2S is the best cleaned, have the lowest values of both C and O, RMS roughness and Ga/N ratio. The
nearly complete removal of C and O were achieved by heating the samples in AES in vacuum.
Wet chemical , Cleaning , GaN , morphology