Experimental study of channel doping concentration impacts on random telegraph signal noise and successful noise suppression by strain induced mobility enhancement

摘要

Impacts of channel doping concentration on single-trap and multiple-trap random telegraph signal (RTS) noise are studied comprehensively in this work, including trap time constants, current fluctuation (ΔId/Id), and threshold voltage shift (ΔVth_rts). It is found that, higher channel doping not only degrades ΔId/Id and ΔVth_rts, but also enhances couplings between gate bias and trap time constants, which is experimentally observed for the first time. Moreover, aiming at RTS suppression in devices with inevitable channel doping, strain effects on RTS are studied. It is found that, RTS noise (Svg) as well as fluctuation amplitudes (ΔId/Id, ΔVth_rts) can be largely suppressed in strained pFETs with higher hole mobility. Underlying physical mechanisms are discussed and guidelines to decrease RTS noise are proposed.