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Pressure dependence of oxide growth rate on silicon and metal silicides
A87 Surface Science 243 (1991) 127-131 North-Holland
127
Pressure dependence of oxide growth rate on silicon and metal silicides L..I. Terminello, J.A. Yarmoff 1, F.M. d'Heurle and F.R. McFeely IBM Thomas J. Watson Research Center, PO Box 218, Yorktown Heights, N Y 10598, USA Received 19 July 1990; accepted for publication 3 August 1990 Si 2p photoemission was used to determine the relative oxidation rates for Si(lll), Ru 2Si3 and CoSi 2. Samples were thermally oxidized at 750 °C with oxygen pressures varying from 1 × 10-6 to 1 Torr. The results confirm that CoSi 2 and Ru 2Si 3 oxidize faster than Si(lll) at "hight" pressures, but reveal the surprising feature that the growth of SiO2 is faster on Si at pressures below 1 × 10 -4 Torr.
132
Surface Science 243 (1991) 132-140 North-Holland
The initial stages of epitaxial growth of silicon on Si(100)-2 x 1 S. Heun, J. Falta and M. Henzler lnstitut ftir FestkSrperphysik, Universitiit Hannover, Appelstrasse 2, 3000 Hannover, Germany Received 18 June 1990; accepted for publication 14 September 1990 Epitaxial growth of Si on Si(100)-2 × 1 has been studied in a temperature range from 290 to 820 K using spot profile analysis of LEED. Intensity and profile of several diffraction spots at different energies have been measured simultaneously with deposition in UHV at a rate of about 1 monolayer in 3 rnin. During growth at 640 K the surface is rough, there are 4 layers growing simultaneously. The anisotropy of the broadening of the 00-beam was taken into account for the determination of the layer distribution. The islands are elongated parallel to the dimer-rows. Already during the, deposition of the first monolayer the final shape of the islands is formed. The average island size during layer-by-layer growth is 30 x 10 atoms. For T = 290 to 400 K deposited atoms cannot cross step edges, so that surface roughness increases rapidly during growth. For T > 750 K the crystal grows via step-propagation.
Surface Science 243 (1991) 141-150 North-Holland
141
The gadolinium-Si(100)2 × 1 interface W.A. Henle, M.G. Ramsey, F.P. Netzer lnstitut fur Physikalische Chemie, Universitiit Innsbruck, A-6020 Innsbruck, Austria
S. Witzel Fachbereich Physik, Unioersitiit Osnabri~ck, W-4500 Osnabriick, Germany
and W. Braun B E S S Y GmbH, Lentzeallee 100, W-IO00 Berlin 33, Germany Received 16 July 1990; accepted for publication 15 October 1990 The formation of the Gd-Si(100)2 × 1 interface and its temperature evolution has been investigated by valence band and core level photoemission using synchrotron radiation, Auger electron spectroscopy and LEED. Compared to Si(lll)7 × 7 the reactivity of Gd on the Si(100)2 x 1 substrate is enhanced and a greater tendency for intermixing of Gd and Si is observed. As on Si(lll) a multiphase interface is formed. The phase diagram of Gd on Si(100) shows ordered LEED structures at elevated temperature suggesting the formation of epitaxial silicide phases; order and stability of these phases on Si(100) are less well pronounced than those of the corresponding silicides on Si(lll). The Auger results suggest a somewhat different disilicide stoichiometry on Si(100) as compared to Si(l 11).
127
Pressure dependence of oxide growth rate on silicon and metal silicides L..I. Terminello, J.A. Yarmoff 1, F.M. d'Heurle and F.R. McFeely IBM Thomas J. Watson Research Center, PO Box 218, Yorktown Heights, N Y 10598, USA Received 19 July 1990; accepted for publication 3 August 1990 Si 2p photoemission was used to determine the relative oxidation rates for Si(lll), Ru 2Si3 and CoSi 2. Samples were thermally oxidized at 750 °C with oxygen pressures varying from 1 × 10-6 to 1 Torr. The results confirm that CoSi 2 and Ru 2Si 3 oxidize faster than Si(lll) at "hight" pressures, but reveal the surprising feature that the growth of SiO2 is faster on Si at pressures below 1 × 10 -4 Torr.
132
Surface Science 243 (1991) 132-140 North-Holland
The initial stages of epitaxial growth of silicon on Si(100)-2 x 1 S. Heun, J. Falta and M. Henzler lnstitut ftir FestkSrperphysik, Universitiit Hannover, Appelstrasse 2, 3000 Hannover, Germany Received 18 June 1990; accepted for publication 14 September 1990 Epitaxial growth of Si on Si(100)-2 × 1 has been studied in a temperature range from 290 to 820 K using spot profile analysis of LEED. Intensity and profile of several diffraction spots at different energies have been measured simultaneously with deposition in UHV at a rate of about 1 monolayer in 3 rnin. During growth at 640 K the surface is rough, there are 4 layers growing simultaneously. The anisotropy of the broadening of the 00-beam was taken into account for the determination of the layer distribution. The islands are elongated parallel to the dimer-rows. Already during the, deposition of the first monolayer the final shape of the islands is formed. The average island size during layer-by-layer growth is 30 x 10 atoms. For T = 290 to 400 K deposited atoms cannot cross step edges, so that surface roughness increases rapidly during growth. For T > 750 K the crystal grows via step-propagation.
Surface Science 243 (1991) 141-150 North-Holland
141
The gadolinium-Si(100)2 × 1 interface W.A. Henle, M.G. Ramsey, F.P. Netzer lnstitut fur Physikalische Chemie, Universitiit Innsbruck, A-6020 Innsbruck, Austria
S. Witzel Fachbereich Physik, Unioersitiit Osnabri~ck, W-4500 Osnabriick, Germany
and W. Braun B E S S Y GmbH, Lentzeallee 100, W-IO00 Berlin 33, Germany Received 16 July 1990; accepted for publication 15 October 1990 The formation of the Gd-Si(100)2 × 1 interface and its temperature evolution has been investigated by valence band and core level photoemission using synchrotron radiation, Auger electron spectroscopy and LEED. Compared to Si(lll)7 × 7 the reactivity of Gd on the Si(100)2 x 1 substrate is enhanced and a greater tendency for intermixing of Gd and Si is observed. As on Si(lll) a multiphase interface is formed. The phase diagram of Gd on Si(100) shows ordered LEED structures at elevated temperature suggesting the formation of epitaxial silicide phases; order and stability of these phases on Si(100) are less well pronounced than those of the corresponding silicides on Si(lll). The Auger results suggest a somewhat different disilicide stoichiometry on Si(100) as compared to Si(l 11).