Impact of source-pocket engineering on device performance of dielectric modulated tunnel FET

Tunnel field-effect transistor (TFET) is one of the potential substitutes for bulk MOSFET in lowpower energy-efficient circuits due to its band-to-band tunneling current mechanism. However, they suffer from low ON-state (I-ON ) current and severe ambipolar behaviour which degrades the device performance. In this paper, both the source-pocket doping and gate dielectric engineering are taken into the account to improve the analog performance of TFET. The ambipolar current(I-AMB) can be supressed effectively without degrading the ON-state current performance by placing high-k and low-k dielectric at the source and drain end respectively. The ON-state current of the same structure can be maximized further by placing a heavily doped pocket layer in the vicinity of the tunneling junction. Here, the width and position of the source-pocket layer are also optimized to provide maximum I-ON /I-AMB . The different DC characteristics such as electric field, energy band analysis, BTBT generation rate and drain current of the proposed device are investigated. The results are compared with the results of conventional low-k TFET, high-k TFET, and hetero-dielectric TFET (HD-TFET) models to show its superiority. We have simulated the different models presented here using Sentaurus TCAD tool.