Comparative investigation of novel hetero gate dielectric and drain engineered charge plasma TFET for improved DC and RF performance. (November 2017)

• Record Type: Journal Article
• Authors: Yadav, Dharmendra Singh; Verma, Abhishek; Sharma, Dheeraj; Tirkey, Sukeshni; Raad, Bhagwan Ram
• Is Part Of: Superlattices and microstructures. Volume 111(2017)
• Page Start: 123
• Page End: 133
• Publication Date: 2017-11
• Subjects: Charge plasma -- Band to band tunneling -- Ambipolar conduction -- Work function engineering -- Sub-threshold swing -- Gate to drain capacitance; Superlattices as materials -- Periodicals; Microstructure -- Periodicals; Semiconductors -- Periodicals; Superréseaux -- Périodiques; Microstructure (Physique) -- Périodiques; Semiconducteurs -- Périodiques; 621.38152
• DOI: 10.1016/j.spmi.2017.06.016
• Languages: English
• ISSNs: 0749-6036

Abstract

Abstract: Tunnel-field-effect-transistor (TFET) has emerged as one of the most prominent devices to replace conventional MOSFET due to its ability to provide sub-threshold slope below 60 mV/decade ( S S ≤ 60 mV/decade) and low leakage current. Despite this, TFETs suffer from ambipolar behavior, lower ON-state current, and poor RF performance. To address these issues, we have introduced drain and gate work function engineering with hetero gate dielectric for the first time in charge plasma based doping-less TFET (DL TFET). In this, the usage of dual work functionality over the drain region significantly reduces the ambipolar behavior of the device by varying the energy barrier at drain/channel interface. Whereas, the presence of dual work function at the gate terminal increases the ON-state current ( I O N ). The combined effect of dual work function at the gate and drain electrode results in the increment of ON-state current ( I O N ) and decrement of ambipolar conduction ( I a m b i ) respectively. Furthermore, the incorporation of hetero gate dielectric along with dual work functionality at the drain and gate electrode provides an overall improvement in the performance of the device in terms of reduction in ambipolarity, threshold voltage and sub-threshold slope along with improved ON-state current and high frequency figures of merit. Highlights: Drain and gate work function engineering with hetero gate dielectric is introduced for the first time in charge plasma based doping-less TFET (DL TFET). The combined effect of dual work functionality at the gate and drain electrode results in the increment of ON-state current ( ION ) and decrement in ambipolar conduction ( Iambi ) respectively. The incorporation of hetero gate dielectric and dual work functionality at the drain and gate electrode provides overall improvement in the DC and RF performance of the device. The hetero gate dielectric and drain metal engineering improves the ION /IOF F ratio and threshold voltage of the proposed device. Cut off frequency ( fT ) and gain bandwidth product ( GBP) have attained its peak at low Vgs providing high operational speed and making it efficient for ultra low power applications.