Impact of uniform and non-uniform doping variations for ultrathin body junctionless FinFETs

Abstract

In this paper, 3-D device simulations are performed to analyze the variations of uniform and non-uniformly (Gaussian) doped junctionless FinFETs. The impact of Fin width (Fw), Fin height (Fh), Channel length (Lg) and Gate Oxide (tox) on drain current, ION/IOFF ratio, subthreshold swing, Drain Induced Barrier Lowering (DIBL) of Si based Bulk Junctionless FinFETs is investigated. The results shows that the ION = 183μA/μm, IOFF = 4.449 × 10−5 μA/μm, is achieved for non-uniformly doping when compared to uniform doping configurations with ION = 102 μA/μm, IOFF = 3.05 × 10−5 μA/μm of junctionless FinFETs. Furthermore, the results also shows that non-uniformly doped junctionless FinFETs with fin width of 6 nm exhibits better DIBL of 22.5 mV/V and Subthreshold swing of 62.04 mV/decade than the uniform doped junctionless FinFET with DIBL of 80 mv/V and Subthreshold swing of 67.62 mV/decade. Thus, the non-uniformly doped junctionless FinFETs can effectively improve the performance of Junctionless FinFETs. In addition, to reduce the leakage current in bulk FinFETs effect of Punch-through Stop (PTS) layer, bulk doping concentration and body bias variations are studied. Finally, the 6T-SRAM circuit was implemented for JL-FinFETs and the results suggest that Gaussian doping JL-FinFETs strengthens the applicability of SRAM in the memory design.