X-RAY PHOTOELECTRON SPECTROSCOPIC AND ATOMIC-FORCE MICROSCOPIC STUDY OF GAAS ETCHING WITH A HCL SOLUTION

GaAs(100) substrates covered with native oxides have been etched with a HCl solution for 10-20 min and subsequently rinsed with water for se veral seconds. The surface of the GaAs substrate thus prepared has bee n examined with atomic force microscopy. The surface flatness is impro ved by this wet etching and the surface undulation remains within a +/ - 1 monolayer fluctuation over a 1 mum x 1 mum surface area. X-ray pho toelectron spectroscopy has been used to examine the chemical composit ion of the GaAs(100) surfaces after the HCl/H2O wet etching sequences. UV photoirradiation of the GaAs surface treated with the HCl solution has been performed to characterize the chlorides on the GaAs surface.