Effect of Source–Drain Doping on Subthreshold Characteristics of Short-Channel DG MOSFETs

The effect of source-drain (S-D) doping on short-channel effects (SCEs) of double-gate MOSFETs is investigated by analytically solving the 2-D potential function in subthreshold. The depleted bands of the degenerately doped S-D regions are coupled to the channel bands through continuity of the electric field at the junction. Both the conduction band profile and the subthreshold Ids-Vg characteristics generated from the analytical model are in agreement with 2-D numerical simulations (TCAD). The results show that S-D doping plays a prominent role on SCE when the channel length is scaled to 10-15 nm. A lighter doped S-D helps lessen SCE by softening the boundary conditions at the junction and absorbing part of the band bending in the S-D depletion regions.