In situ observation of surface processes in InAs/GaAs(001) heteroepitaxy: The role of As on the growth mode

Surface processes of the growing thin films of InAs on GaAs(001) substrates have been studied as a function of substrate temperature and As to In flux ratio. They have been observed by reflection high-energy electron diffract ion and total-reflection-angle x-ray spectroscopy in real time. At temperat ures lower than similar to 480 degreesC, InAs grows in a Stranski-Krastanov mode irrespective of the As/In flux ratio, while the growth mode of InAs s trongly depends on the flux ratio above similar to 500 degreesC. We have fo und that the sticking probability of In decreases as the As flux is decreas ed above similar to 500 degreesC, which results in the changes in the growt h mode of InAs. (C) 2001 American Institute of Physics.