Controlling of short channel effects in pocket implanted Ge channel pMOSFETs with high-k gate stacks

摘要

Germanium has emerged as a potential contender to long-standing Si due largely to its augmented bulk carrier mobility, especially for holes. Nevertheless Ge MOSFETs suffer from poor interface properties and exhibit early onset of short channel effects (SCEs). Here we investigate how SCEs in Ge devices can be controlled by employing halo implants in presence of interface and fixed trap charge densities. Also halo implants are optimized to obtain a constant threshold voltage over a wide variation of channel lengths, In addition we study the effect of substrate bias in controlling short channel effects. Further the combined effects of halo concentration and substrate bias are investigated to attain a specified value of threshold voltage over a wide variation of channel lengths down to 50 nm. Results obtained from our model show excellent agreement with numerical simulation data obtained using ATLAS and also with reported experimental data.