Performance Improvement In Nanoscale Ge-Gaas Heterojunction Junctionless Tunnel Fet Using A Dual Material Gate

In this paper we have proposed the use of Dual Material Gate (DMG) in a Junctionless Tunnel FET using Ge as the body material for Band to band tunnelling. Two adjacently spaced gates (control gate and p-gate) are used with uniformly doped n-type channel, avoiding the use of any use of p-n junction. Germanium (Ge) is used as a source in order to obtain a high ON-current. The use of high band gap material (GaAs) as a drain forms a heterojunction and prevents any undesired OFFstate band-to-band-tunneling. Using appropriate work functions for the auxiliary and tunnel gate, we have achieved a significant improvement in the performance of the device. Simulations performed using the DMG Heterojunction Junctionless Tunnel FET (DMG-HJLTFET) results in a high ION/IOFF ratio and reduced subthreshold slope. The DMG-HJLTFET shows better immunity against Drain Induced Barrier Lowering (DIBL). We have also presented the suitability of the DMG-HJLTFET for low power application with V-DD = 0.5 V. The optimised with VDD = 0.5 V, recorded an average subthreshold slope of 8.6 mV/dec and /(ON)/(OFF) ratio close to 10(12).