Properties of adsorbates on III-V semiconductors

In order to develop a III-V MOSFET device it is important to have an atomic understanding of both the clean III-V surface reconstruction and the interface formed when an adsorbate is deposited onto the surface. Three promising channel materials for a III-V MOSFET devices are GaAs, InAs, and InGaAs. In an effort to obtain an atomic understanding of the III-V materials and the interfaces that form when adsorbates bond to them, three critical techniques [scanning tunneling microscopy (STM), scanning tunneling spectroscopy (STS), and density functional theory (DFT)] were employed. STM was used to characterize the adsorbate/semiconductor interface along with identifying previously undetermined surface reconstructions. The electronic properties of the system were examined by taking STS spectra, which reveal how the adsorbate changes the electronic properties of the semiconductor after bonding. In addition, DFT was used to confirm experimental results along with predicting other adsorbate/semiconductor interactions.