Analytical modeling of transport phenomena in III-V heterojunction triple metal gate all around tunneling field effect transistor

Abstract

Tunneling Field Effect Transistor (TFET) is great for its energy efficiency and low stand- by power switch performance. Additionally, Gate All Around (GAA) based structures are used to improve the low on-current (Ion) and to overcome the corner effect and short channel effects of a planar TFET. Staggered or broken bandgap heterojunction with III-V heterojunction at the source-channel junction improve the Band to band tunneling (BTBT) rate notably. Gate work function engineering is another novel technique to improve performance. Only a handful of models are available for heterojunction GAA structure and no model proposed for III-V heterojunction multiple- metal GAA TFET till now. Therefore, an analytical model for the transport phenomena of a III-V heterojunction triple metal gate all around tunneling field effect transistor (HTM GAA TFET) is developed for the first time in this thesis work. The continuous surface potential profile of the staggered-gap aligned heterojunction device is achieved by solving Poisson’s equation and then Kane’s model for band to band tunneling is used to derive the drain current of the device. The comparison between the modeling results and TCAD simulation results with GaAs0.5Sb0.5/In0.53Ga0.47As heterojunction stem satisfactory consistency. The robust and compatible model approaches the surface potential, electric field, band to band tunneling generation rate and drain current in a III-V HTM GAA TFET in a methodical manner.