The Impact of Fin Number on Device Performance and Reliability for Multi-Fin Tri-Gate n- and p-Type FinFET

In this paper, the effect of carrier quantization on device characteristics and stress-induced device degradation for multifin high-κ/metal tri-gate n-type and p-type fin field-effect transistors (FinFETs) were investigated through electrical characterization and simulation. Carrier conduction in the steep Si fins of FinFETs is different for devices with different numbers of fins and affects device performance and reliability. For n-type FinFETs, devices with fewer fins inhibited the coupling effect between fins to exhibit superior device performance but underwent more severe hot carrier-induced device degradation. The coupling effect between fins reduced the equivalent electric field in the multifin devices and further inhibited impact ionization; thus, devices with more fins achieved superior reliability to single-fin devices after hot-carrier stress. For p-type FinFETs, a similar effect on performance was demonstrated but with lower sensitivity to hot-carrier stress-induced device degradation caused by lower hole mobility within the Si fin channel.