~i1 ~ CRYSTAL GROWTH ELSEVIER Journal of Crystal Growth 143 (1994) 22—28 ______________________ Micro-scribes in semi-insulating GaAs studied by cross-sectional transmission electron microscopy Fredric Ericson a,* Kias Hjort a Jan- ke Schweitz a Sven Andersson b, Erik Janzén b a Materials Science Division, Uppsala University, Box 534, S- 751 21 Uppsala, Sweden h Department of Physics and Measurement Technology, Linköping University, S-581 83 Linköping, Sweden Received 8 December 1993; manuscript received in final form 11 May 1994 Abstract A micromanipulator was used to create well-defined and exactly oriented micro-scribes in a GaAs (001) wafer surface. The resulting dislocation slip systems were identified by cross-sectional transmission electron microscopy (XTEM). A heating sequence simulating that of a standard epitaxial process was applied, and the response of the lattice defects was investigated by XTEM. It was found that differently oriented micro-scribes generate different types of plasticity behaviour, and that subsequent annealing causes considerable recovery of the strain-hardened zones near the scribes. These observations are of importance to the understanding of the transfer of dislocations from a damaged substrate to an epilayer. 1. Introduction chart the various types of lattice defects which occur at micro-scribes and other surface damage GaAs is commonly used in optronics and in GaAs, and to study how these lattice defects high-speed electronics, but also in solar cells and are affected by the thermal cycling during epitax- micromechanical devices. Surface damage may be ial growth. detrimental to all of these applications; some- This paper is the first in a series aiming at an times due to harmful effects on the electronic or improved understanding of lattice defects gener- optical properties caused by dislocation move- ated by surface damage, and their influence on ment, and sometimes due to a serious reduction an epitaxial process. The specific aim of the first of the mechanical strength. Also, GaAs is com- article is to use a micro-manipulator to create monly used in heterostructures, where minute well-defined and exactly oriented micro-scribes in surface defects in the GaAs substrate can be a GaAs(OO1) surface, to characterize the resulting transferred into an epitaxial layer, and eventually dislocation slip systems by means of transmission cause, e.g., catastrophic degradation of optical electron microscopy (TEM), and to investigate components. For these reasons it is of interest to how these lattice defects respond to a heating sequence simulating that of a standard epitaxial process. The generation and dynamics of dislocations at * Corresponding author. microhardness indentations in GaAs are well 0022-0248/94/$07.00 © 1994 Elsevier Science B.V. All rights reserved SSDI 0022-0248(94)00410-N