2019 China Semiconductor Technology International Conference (CSTIC) | 2019
The investigation of source doping effect on on-state current in homojunction and heterojunction Tunneling FETs
Abstract
This paper investigates the influence of source doping effects (SDEs) on the tunneling probability TE(E) and on-state currents in homojunction and heterojunction tunneling FETs (TFETs). A unified formulism in the piecewise two band E-k relationship is applied to analyze SDEs in TFETs with different staggered energy band Δ. Both the analytical and numerical results show that as source doping concentration (Ns) increases, TE(E) in homojunction TEFTs increases, while TE(E) in hetero-junction TFETs first increases and then decreases. An optimum source doping concentration (Nopt) exists that maximizes the current in heterojunction TFETs, and Nopt increases as Δ increases, while current in homojunction TEFTs is not sensitive to the source doping concentration when heavily doped.