K. Prabhakaran et al., Distinctly different thermal decomposition pathways of ultrathin oxide layer on Ge and Si surfaces, APPL PHYS L, 76(16), 2000, pp. 2244-2246
The thermal decomposition pathway of an ultrathin oxide layer on Ge(100) an
d Si(100) surfaces is examined by synchrotron radiation photoelectron spect
roscopy and ultraviolet photoelectron spectroscopy with helium I radiation.
The as-prepared oxide layer consists of a mixture of oxides, namely, subox
ides and dioxides, on both the surfaces. Upon annealing, the oxide layers d
ecompose and desorb as monoxides. However, we find that the decomposition p
athways are different from each other. On annealing Ge oxides, GeO2 species
transform to GeO and remain on the surface and desorb at > 420 degrees C.
In contrast, annealing of Si oxides results in the transformation of SiO to
SiO2 up to temperatures (similar to 780 degrees C) close to the desorption
. At higher temperatures, SiO2 decomposes and desorbs, implying a reverse t
ransformation to volatile SiO species. (C) 2000 American Institute of Physi
cs. [S0003-6951(00)04816-6].