The Interaction of Laser Generated Methyl Radicals with Cd, Te, and CdTe Surfaces

Abstract

AbstactThe mechanism of the interaction of methyl radicals with Cd, Te, and CdTe surfaces has been studied in ultrahigh vacuum by Auger electron spectroscopy and thermal desorption mass spectrometry. Methyl radicals generated by the laser photodissociation of acetone at 193 nm efficiently etch both Te and Te-rich CdTe surfaces. However, there is no evidence for reaction of methyl radicals with Cd or stoichiometric CdTe. A temperature dependence in the rate of methyl radical etching of Te-rich CdTe is related to a competition between acetone scavanging of radicals on the surface and reaction of radicals to form volatile metalorganics. Acetone itself has a small but finite reaction probability with Te and Te-rich CdTe surfaces.