STRAIN-MODULATED EPITAXY - MODIFICATION OF GROWTH-KINETICS VIA PATTERNED, COMPLIANT SUBSTRATES

Bonded, thin film compliant substrates can be used to reduce the strai n in a lattice-mismatched overlayer during epitaxial growth. We have p resented an initial demonstration of the use of thin film GaAs complia nt substrates fabricated by epitaxial liftoff or substrates removal an d bonded to a mechanical host. This processing approach can be coupled with the patterning of the bended surface to realize a lateral thickn ess variation. This thickness variation, in turn, can be used to reali ze a lateral strain variation in the growing mismatched overlayer. The strain can then be used to modify molecular beam epitaxy (MBE) growth kinetics, such as cation desorption and migration. With this techniqu e the lateral control of composition and thickness can be realized wit hout any surface topography. In this article, we discuss the growth of InGaAs films on compliant substrates produced by epitaxial lift-off a nd substrate removal. In addition, we discuss the various extrinsic ef fects associated with the compliant substrates, including the effects of the bonding and the results of MBE temperature cycling experiments. Finally, the characteristics of InGaAs thin films grown on GaAs patte rned compliant substrates are presented. (C) 1996 American Vacuum Soci ety.