Spacer Length and Tilt Implantation Influence on Scaled UTBOX FD MOSFETs

Abstract

Fully Depleted (FD) MOSFETs on Ultra-Thin Buried Oxide (UTBOX) are studied in this paper based on the main digital/analog parameters, by focusing on experimental results. Higher spacer lengths show decreased short channel effects and superior analog performance compared to the standard S/D junction devices with LDD. However, for smaller spacer lengths the underlap formation is suppressed by the lateral diffusion of dopant. The same trend is exhibited by tilt-implanted devices, where the different implantation angle favors the dopant diffusion into the underlap region and the channel, degrading the transistor performances.