PHOSPHINE CHEMISTRY ON MO(110) AND OXIDIZED MO(110)

The adsorption and desorption of phosphine and the oxidation of phosph orus on Mo(110) and oxidized Mo(110) have been studied by using Auger electron spectroscopy (AES), temperature-programmed desorption (TPD), and low-energy electron diffraction (LEED). Both molecular desorption and dissociative processes were observed on Mo(110), leaving adsorbed P(a) species in a c(4 x 1) over layer structure. The P(a) species do n ot undergo diffusion into the bulk below 1000 K. On the oxidized Mo(11 0) surface, the phosphine adsorption and dissociation process was inhi bited significantly. Phosphorus on the Mo(110) surface could be oxidiz ed to produce PO(g) and PO2(g) Species near 900 K, as detected by line -of-sight mass spectrometry; neither P2O3(g) nor P2O5(g) was observed.