Modeling and simulation study on the nano-scaled schottky-barrier junction and MOSFETs

Abstract

The importance of reducing parasitic resistance and capacitance in the source/drain (S/D) region of metal-oxide-semiconductor field-effect-transistors (MOSFETs) has been emphasized as the device size is scaled down to nanometer regime. For this reason, Schottky-barrier (SB) MOSFETs having metallic S/D instead of heavily doped semiconductor have been regarded as one of the most promising candidates for the future devices. They have also great other benefits as nano-scaled devices such as low thermal budget and abrupt interfaces between the metal and semiconductor. Despite their excellent features, we find that they suffer from low ON-state current. In this thesis, the performance of Ge and III-V channel SB-MOSFETs are assessed by quantum transport simulations to overcome this problem. Moreover, we have investigated the SB height (SBH) of the various nanostructured junctions, which is a key parameter for determining the performance of nano-scaled SB-MOSFETs, using the density function theory (DFT). Based on the simulation results, we suggest a new model to predict the SBHs of nanostructured junctions properly from the bulk SBH.