Wet-chemical etching of GaAs(211)B wafers for controlling the surface properties

Substrate surface plays an important role to achieve high performance infrared devices and high-quality film layers. GaAs (211)B wafers were intensively used in infrared detector applications. Despite 'epiready' wafers can easily be found on the market, most of them have defects and contaminations due to their fabrication processes. The defects and contaminations on wafers may have deleterious effects on thin film growth and detector applications. To overcome such problems, various chemical treatments should be implemented prior to thin film growth. In this study, to understand the effect of wet chemical cleaning process on epiready (211)B GaAs wafers, piranha solution-based wet chemical etching was performed. After these treatments, the surfaces of GaAs wafers were investigated by atomic force microscopy and scanning electron microscopy. Energy dispersive X-ray spectroscopy was used to assess the chemical composition of the surface. The vibrational modes and two-dimensional maps were observed by a Raman spectroscopy.