Structure-sensitive oxidation of the indium phosphide (001) surface

The oxidation of anion- and cation-rich indium phosphide (001) has been investigated by exposure to unexcited molecular oxygen. Indium phosphide oxidation is an activated process and strongly structure sensitive. The In-rich delta(2x4) surface reacts with oxygen at 300 K and above. Core level x-ray photoemission spectra have revealed that the O-2 dissociatively chemisorbs onto the delta(2x4), inserting into the In-In dimer and In-P back bonds. By contrast, the P-rich (2x1) reconstruction does not absorb oxygen up to 5x10(5) Langmuir at 300 K, as judged by the unperturbed reflectance difference spectrum and low energy electron diffraction pattern. Above 455 K, oxygen reacts with the (2x1) inserting preferentially into the In-P back bonds and to a lesser extent into the phosphorus dimer bonds. (C) 2002 American Institute of Physics.