In-situ scanning tunneling microscopy observation of InAs quantum dots on GaAs(001) during molecular beam epitaxy growth

Scanning tunneling microscopy (STM) has proved to be an invaluable tool for probing epitaxial growth phenomena in general, and has been successfully applied to many GaAs-based materials grown by molecular beam epitaxy (MBE). Typical STM-MBE experiments involve quenching the sample and transferring it to a remote STM chamber under arsenic-free ultra-high vacuum (UHV). In the case of GaAs-based materials grown at substrate temperatures of 400-600 °C, operating the STM at room temperature ensures that the surface is essentially static on the time scale of STM imaging. To attempt dynamic experiments requires a system in which STM and MBE were incorporated into one unit rather than in separate chambers in order to scan in situ during growth. In this paper, we discussed the observation on the heteroepitaxial growth of InAs on GaAs(001) by this system along with prospects for key in situ STM experiments.