Performance Enhancement of Novel Dopingless TFET Using Raised Source and Recessed Drain

Abstract

A novel raised source and recessed drain dopingless tunneling FET (RSRD-DL-TFET) is proposed in this paper. By using TCAD simulation, the DC electrical characteristics, energy-band diagrams, carrier concentrations and band-to-band tunneling generation rate of RSRD-DL-TFET are analyzed, as compared with planar dopingless tunneling FET (PDL-TFET). Besides, analog/RF and transient performances for both devices are also investigated, including transconductance, parasitic gate capacitance, cut-off frequency, gain bandwidth product and fall propagation delay. Benefiting from the design of raised source and recessed drain, the proposed device not only creates the line tunneling in the source region, but also reduces the ambipolar tunneling distance at drain/channel interface. As a result, the proposed RSRD-DL-TFET could provide higher on-current, steeper subthreshold swing, lower ambipolar current, higher cut-off frequency and better transient performance than PDL-TFET.