Aluminum films were deposited in ultra-high vacuum onto heat-cleaned-surfaces as well as oxygen-free MBE surfaces of (100) GaAs to form Schottky barriers with and without intervening oxide layers. The measured ideality factor n was close to unity (nç1.02ç1.10) irrespective of the oxide thickness tox, indicating the transport being dominated by thermionic emission processes. In contrast, the barrier height decreased systematically from 0.89 eV to 0.67 eV, as toxis reduced, suggesting the presence of negatively charged centers (≃1012/cm2) at GaAs/oxide interfaces.
ASJC Scopus subject areas
- Physics and Astronomy(all)