Analysis of Flatband Voltage for MOS Devices using High-K Dielectric Materials

摘要

In this paper we have calculated Flatband voltage (V_(FB)) in terms of interface trap charges, fixed oxide charges and oxide trapped charges for thin oxide Metal Oxide Semiconductor (MOS) Devices using different high-k dielectric materials such as HfO2, ZrO2, Al2O3 and Si3N4. It has been found that the V_(FB) shift of all the samples indicated negative due to the existence of deep donor type surface states and positive interface charges, and these effects are highly responsible for variation in interface trap density with oxide thickness. It has been evaluated that, with respect to SiO2 for the same oxide thickness, high-k contributes less to V_(FB). As we move to greater dielectric constant, V_(FB) approaches to zero for the same oxide and interface charge. Excellent agreement has been observed for theoretical and simulation results.