K-promoted oxidation of GaSb (1 1 0): the effects of potassium coverage and substrate temperature

• Published in: Applied surface science Vol. 182; no. 1; pp. 25 - 31
• Main Authors: Ji, M.R., Yang, H.W., Wu, J.X., Ma, M.S., Zhu, J.S., Zhang, Y.H.
• Format: Journal Article
• Language: English
• Published: Amsterdam Elsevier B.V 05.11.2001; Elsevier Science
• Subjects: Alkali metals; Cross-disciplinary physics: materials science; rheology; Exact sciences and technology; Materials science; Oxidation; Photoelectron spectroscopy; Physics; Semiconductor; Surface treatments; Semiconductor; Oxidation; Photoelectron spectroscopy; Alkali metals; Inorganic compounds; Gallium antimonides; Ultraviolet photoelectron spectra; Surface treatments; Coverage rate; Experimental study; Potassium; Passivation; Preadsorption; X-ray photoelectron spectra
• ISSN: 0169-4332; 1873-5584
• DOI: 10.1016/S0169-4332(01)00390-7

Potassium-promoted oxidation of the GaSb (1 1 0) surface has been comparatively studied under different combinations of substrate temperature and K-coverage using X-ray photoelectron spectroscopy and ultraviolet photoelectron spectroscopy. Various species of oxygen (O 2−, O 2 2− and O 2 −) have been observed under different conditions. We find that K-coverage and a proper substrate temperature (500 K) is favorable for the oxidation of the semiconductor, with temperature being even more effective than K-coverage. The efficiency of the promoted oxidation is discussed for different experimental conditions. We conclude that the oxidation ability of the oxygen species follows the order KO 2, K 2O 2 and K 2O, and that the fraction of the different species depends on the local atomic ratio of K/O and the substrate temperature.