Surface Oxidation Study of Silicon-Doped GaAs Wafers by Ftir Spectroscopy

Abstract

AbstractA surface study of Si-doped GaAs (100) oriented wafers treated with NH4OH and HC1 following exposure to fluorine containing plasma was conducted using fourier transform infrared spectroscopy (FTIR). These treatments were observed to produce various oxidation products, such as AS2O5 and GaO. Though inorganic salts, such as (NH4)3GaF6, can be formed on the Si-doped GaAs wafers during cleaning with hydrofluoric acid buffered with ammonium fluoride, the applied cleaning method which consisted of NH4OH and HCl treatments subsequent to exposure to fluorine containing plasma did not induce formation of any inorganic salts. A small amount of hydroxide group was also presented in the samples. Water molecules and ammonium hydroxide can be sources of OH which can then be incorporated interstitially into the wafer surfaces.