Simulation and Analysis of Interface Properties Due to Variation of Gate Oxide Thickness in Au/Al2O3/n-GaSb MOSCAP

In this paper interface properties of Au/Al2O3/n-GaSb MOSCAP has been explored for different gate oxide thickness using TCAD tool. The electrical characteristic of Al2O3/n-GaSb MOSCAP was analyzed at 300 K. From the capacitance-voltage (C-V) characteristics of the simulated MOSCAP structure interface state density (D-it) and surface potential at different thickness of Al2O3 (10 nm, 7.5 nm, 5 nm) were calculated. The calculated' Dit was found to be in the order of 10(13) cm(-2) eV(-1) using Terman method and is found to decrease with the increase of Al2O3 thickness. Also the interface trap density was found as a function of surface potential. From the relation it can be predicted that in case of fabricated devices the transition may be more gradual.