Time-resolved reflectance difference spectroscopy of InAs growth under alternating flow conditions

We report a time-resolved reflectance difference spectroscopy (RDS) study o f the growth of InAs during alternating flow conditions typical of atomic l ayer epitaxy (ALE). The precursors used were trimethylindium (TMIn) and ter tiarybutylarsine (TBAs). For ALE growth we observe that the InAs surface re mains As-rich for an appreciable fraction of the 1 monolayer (ML) TMIn puls e. This is similar to results obtained for the growth of GaAs by ALE using trimethylgallium. Three distinct RDS spectra are observed, two correspondin g to As-rich phases, and one which is In-rich. In both InAs and GaAs the ex tra As layer appears to play a key role in maintaining self-limiting behavi our. (C) 1998 Elsevier Science B.V. All rights reserved.