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Surface structures of Si(100)-Al phases
A43 J.E. G R E E N E
Department of Materials Science, The Coordinated Science Laboratory, and The Materials Research Laboratory, 1101 W. Springfield Avenue, University of Illinois, Urbana, 1L 61801, USA Received 17 August 1988; accepted for publication 14 October 1988 The structure and surface morphology of In overlayers on Si(100) surfaces were investigated as a function of substrate temperature and surface coverage using low-energy and reflection high-energy electron diffraction as well as Auger electron spectroscopy. Desorption kinetics of adsorbed In was studied with modulated-beam desorption and temperature-programmed desorption spectroscopies. Indium was found to grow on Si(100) according to a Stranski-Krastanov mechanism with the initial formation of several two-dimensional phases preceding the nucleation and growth of three-dimensional In islands. Binding energies and frequency factors were extracted from the desorption measurements using a model based on first-order desorption from several interdependent surface phases. First-order and zeroth-order kinetics were observed for the total desorbing flux from coexisting surface phases.
Surface Science 209 (1989) 335-344 North-Holland, Amsterdam SURFACE
STRUCTURES
T. I D E , T. N I S H I M O R I
335 OF Si(100)-Al PHASES
a n d T. I C H I N O K A W A
Department of Applied Physics, Waseda University, 3-4-1, Ohkubo, Shinjuku-ku, Tokyo 160, Japan Received 1 August 1988; accepted for publication 27 October 1988 The surface structures of Si(100)-AI phases of coverages less than one monolayer were studied by low energy electron diffraction (LEED) and Auger electron spectroscopy (AES). 2 x 2, 2 × 3, 4 x 5, 1 x 7 and c(4 x 12) structures appeared depending on the coverage and substrate temperature during deposition. On the basis of the similarity of their LEED patterns in Si(100)-column-IIl systems (A1, Ga and In) and the fine structures of the surface states measured by AES in the present experiment, the structure models of Si(100)2 x 2-A1 and 2 x 3-AI are presented.
Surface Science 209 (1989) 345-363 North-Holland, Amsterdam GROWTH AND ATOMIC ON W(llO) AND W(100) P a u l J. B E R L O W I T Z
STRUCTURE
345 OF CHROMIUM
* a n d N e a l D. S H I N N
OVERLAYERS
**
Sandia National Laboratories, Division 1134, Albuquerque, N M 87185, USA Received 29 June 1988; accepted for publication 3 October 1988 The growth, structure and thermal stability of chromium overlayers vapor-deposited onto W(ll0) and W(100) substrates have been studied using Auger electron spectroscopy, temperature programmed desorption, work function measurements and low energy electron diffraction. Layer-by-layer growth is observed on both substrates in the 120-400 K temperature range, despite a 9% Cr : W bulk lattice mismatch. On W(ll0), a pseudomorphic (1 x 1) Cr monolayer (ML) forms
Department of Materials Science, The Coordinated Science Laboratory, and The Materials Research Laboratory, 1101 W. Springfield Avenue, University of Illinois, Urbana, 1L 61801, USA Received 17 August 1988; accepted for publication 14 October 1988 The structure and surface morphology of In overlayers on Si(100) surfaces were investigated as a function of substrate temperature and surface coverage using low-energy and reflection high-energy electron diffraction as well as Auger electron spectroscopy. Desorption kinetics of adsorbed In was studied with modulated-beam desorption and temperature-programmed desorption spectroscopies. Indium was found to grow on Si(100) according to a Stranski-Krastanov mechanism with the initial formation of several two-dimensional phases preceding the nucleation and growth of three-dimensional In islands. Binding energies and frequency factors were extracted from the desorption measurements using a model based on first-order desorption from several interdependent surface phases. First-order and zeroth-order kinetics were observed for the total desorbing flux from coexisting surface phases.
Surface Science 209 (1989) 335-344 North-Holland, Amsterdam SURFACE
STRUCTURES
T. I D E , T. N I S H I M O R I
335 OF Si(100)-Al PHASES
a n d T. I C H I N O K A W A
Department of Applied Physics, Waseda University, 3-4-1, Ohkubo, Shinjuku-ku, Tokyo 160, Japan Received 1 August 1988; accepted for publication 27 October 1988 The surface structures of Si(100)-AI phases of coverages less than one monolayer were studied by low energy electron diffraction (LEED) and Auger electron spectroscopy (AES). 2 x 2, 2 × 3, 4 x 5, 1 x 7 and c(4 x 12) structures appeared depending on the coverage and substrate temperature during deposition. On the basis of the similarity of their LEED patterns in Si(100)-column-IIl systems (A1, Ga and In) and the fine structures of the surface states measured by AES in the present experiment, the structure models of Si(100)2 x 2-A1 and 2 x 3-AI are presented.
Surface Science 209 (1989) 345-363 North-Holland, Amsterdam GROWTH AND ATOMIC ON W(llO) AND W(100) P a u l J. B E R L O W I T Z
STRUCTURE
345 OF CHROMIUM
* a n d N e a l D. S H I N N
OVERLAYERS
**
Sandia National Laboratories, Division 1134, Albuquerque, N M 87185, USA Received 29 June 1988; accepted for publication 3 October 1988 The growth, structure and thermal stability of chromium overlayers vapor-deposited onto W(ll0) and W(100) substrates have been studied using Auger electron spectroscopy, temperature programmed desorption, work function measurements and low energy electron diffraction. Layer-by-layer growth is observed on both substrates in the 120-400 K temperature range, despite a 9% Cr : W bulk lattice mismatch. On W(ll0), a pseudomorphic (1 x 1) Cr monolayer (ML) forms