OXIDATION OF INXGA1-XASYP1-Y BY NO2 STUDIED WITH AUGER-ELECTRON SPECTROSCOPY

We have studied the oxidation of quaternary InGaAsP materials by NO2, using Auger electron spectroscopy for both elemental and chemical analysis of the surface. We report that NO2 induces a preferential oxidation, forming oxides of Ga, In, and P. The As remains unoxidized. From Ar+ ion milling we find that the oxide layers are fairly thin (less than 10 Angstrom), even at high exposures (greater than 1000 L) of NO2, where we obtain a saturation coverage of approximately 0.3 ML (monolayers). We have also measured electron energy loss spectra (EELS) and observe the disappearance of the surface plasmon loss feature upon oxide formation.