Silicon film thickness influence on enhanced dynamic threshold UTBB SOI nMOSFETs

Abstract

This paper investigates the silicon film thickness influence on extensionless Ultra Thin Body and Buried Oxide (UTBB) FDSOI devices applied in a dynamic threshold voltage (DT2) operation (VB=VG) over the conventional one (VB=0V). A 6nm silicon thickness in enhanced DT (eDT), where the back gate bias is a multiple value of the front gate one (VB=k×VG), was also considered and compared to the other configurations and to a 14nm silicon film. The better coupling of a thinner silicon film leads to superior DC parameters like lower subthreshold swing and DIBL, while the thicker device presents a higher gmmax and lower GIDL. Regarding the eDT performance, the parameters of the thinner channel vary less than for the thicker one.