Growth by molecular beam epitaxy of (rare-earth group V element)/III-V semiconductor heterostructures
- PDF / 1,469,114 Bytes
- 11 Pages / 576 x 792 pts Page_size
- 91 Downloads / 213 Views
R. Guerin, S. Deputier, and M. C. Le Clanche Laboratoire de Chimie du Solide et Inorganique Moleculaire, UA CNRS 1495, Campus de Beaulieu, F 35042 Rennes, France
G. Jezequel, B. Lepine, A. Quemerais, and D. Sebilleau Laboratoire de Spectroscopie du Solide, Bat. 11C, URA CNRS 1202, Campus de Beaulieu, F 35042 Rennes, France (Received 29 December 1994; accepted 18 April 1995)
This paper deals with the growth by molecular beam epitaxy of semimetallic (rare-earth group V element) compounds on III-V semiconductors. Results are presented, first on the E r - G a - A s and E r - G a - S b ternary phase diagrams, second on the lattice-mismatched ErAs/GaAs {8a/a = +1.6%), YbAs/GaAs {8a/a ~ +0.8%), and ErSb/GaSb {8a/a ~ +0.2%) heterostructures, and third on the lattice-matched Sco.3ErO7As/GaAs and Sco.2Ybo.8As/GaAs systems {8a/a < 0.05%). Finally the growth of YbSb2 on GaSb(OOl) is reported. The studies made in situ by reflection high-energy electron diffraction (RHEED) and x-ray photoelectron diffraction and ex situ by x-ray diffraction, transmission electron microscopy, He+ Rutherford backscattering, and photoelectron spectroscopy are presented. We discuss the atomic registry of the epitaxial layers with respect to the substrates, the appearance of a mosaic effect in lattice-mismatched structures, and the optical and electrical properties of the semimetallic films. The problems encountered for III-V overgrowth on these compounds (lack of wetting and symmetry-related defects) are commented on, and we underline the interest of compounds as YbSb 2 which avoid the appearance of inversion defects in the GaSb overlayers. I. INTRODUCTION The incorporation of metal layers into semiconductors is attracting growing attention due to potential applications in novel electronic devices and to the new physics of very thin metal films in semiconductors (for recent review articles, see Refs. 1 and 2). Up to now, the growth by molecular beam epitaxy (MBE) of three classes of metallic or semimetallic materials (mainly on GaAs) has been studied: the transition-metal gallides and aluminides like NiGa3 and NiAl,4 the rareearth monoarsenides as YbAs5 and ErAs,6 and recently the Fe-based intermetallic compounds Fe3(Al, Si).7'8 The growth of rare-earth monoarsenides (RE-As), and in a more general way, of the rare-earth monopnictides (RE-V) has a twofold advantage; on the one hand, the epitaxy of the metallic compound is performed at temperatures ranging from 400 °C to 600 °C which are usual in the growth of III-V semiconductor (III-V); on the other hand, in many cases, a precise adjustment of
a) Permanent
address: Laboratoire de Spectroscopie du Solide, Bat. 11C, URA CNRS 1202, Campus de Beaulieu, F 35042 Rennes, France.
1942 http://journals.cambridge.org
J. Mater. Res., Vol. 10, No. 8, Aug 1995 Downloaded: 14 Mar 2015
the flux ratio is not needed as the group-V element atom (V) excess does not adhere to the surface. This paper deals with the growth of RE-V. It is mainly illustrated by results on the lattice-mismatched ErAs/GaAs {8a/a = +1.6
Data Loading...
