Influence of the sidewall crystal orientation, HfSiO nitridation and TiN metal gate thickness on n-MuGFETs under analog operation

Abstract

This work characterizes the analog performance of SOI n-MuGFETs with HfSiO gate dielectric and TiN metal gate with respect to the influence of the high- k post-nitridation, TiN thickness and device rotation. A thinner TiN metal gate is found favorable for improved analog characteristics showing an increase in intrinsic voltage gain. The devices where the high- k material is subjected to a nitridation step indicated a degradation of the Early voltage ( V EA) values which resulted in a lower voltage gain. The 45° rotated devices have a smaller V EA than the standard ones when a HfSiO dielectric is used. However, the higher transconductance of these devices, due to the increased mobility in the (1 0 0) sidewall orientation, compensates this V EA degradation of the voltage gain, keeping it nearly equal to the voltage gain values of the standard devices.