Subthreshold Performance Analysis of Germanium Source Dual Halo Dual Dielectric Triple Material Surrounding Gate Tunnel Field Effect Transistor for Ultra Low Power Applications
An improved subthreshold analytical model of Germanium source Dual Halo Dual Dielectric Triple Material Surrounding Gate Tunnel FET Ge(SRC)-DH-DD-TM-SG-TFET is proposed. The dielectric gate oxide structure is comprised of Silicon-dioxide and Hafnium oxide. The high-K dielectric materials overcomes the Short Channel Effects caused by ultrathin silicon devices. The subthreshold analysis is carried out by solving a 2-D Poisson’s equation using the parabolic approximation method. The electrical characteristics of Ge(SRC)-DH-DD-TM-SG-Tunnel FET are analyzed using a 3-D Sentaurus TCAD device simulator and compared with the silicon based single halo and triple material surrounding gate TFET structures. The proposed model shows a lower ambipolar current and a better ION/IOFF ratio of 106. Moreover, the influence of germanium/silicon in dual dielectric materials has reduced the tunneling barrier width and the ON current (10−4 A/μm) of the proposed device and improved at the level of CMOS transistors.