978-1-4799-2751-7/13/$31.00 ©2013 IEEE Impact of Cha Variation in Sweta Chander ECE Department, NIT Silchar, In sweta.chander@gmail.com Abstract— In this paper we have optimized a based TFET for low power applications with V we have observed the variation of channel thickness on the device which affects switchi such as subthreshold swing, I on and I off . Effec on the subthreshold performance of the SG observed using the Non-Local BTBT model a the ON current is enhanced with increase in r of the gate dielectrics. Synopsys TCAD is optimization of the device which shows the res high I on /I off ratio of 3.4×10 9 and the steepest av swing of 36 mV/ decade. Keywords— Tunnel FET; Subthreshold S Dielectrics; Silicon Germanium on Insulator; Q I. INTRODUCTION In the past few decades MOSFET is the of the semiconductor industry. The steady dimension MOSFET transistors from technology has provided the improveme density, speed, cost and functionality of the each semiconductor technology node, the ch increases with these improvements [1]. For l applications the aggressive scaling of MOSFETs are not suitable as the subth theoretically limited to 60 mV/ decade and scaling of the threshold voltage and sup address this issue, an alternative device is re achieve the steeper switching behavior then MOSFETs. Tunnel FET is the most promising a which allows further reduction the sup therefore threshold voltage. This alterna achieve the required I ON at the significantly well as reduce the leakage current [2]. TFET mechanical phenomena which rely on car band-to-band tunneling and can obtain the s swing than 60 mV/ decade [3-4]. In spite o the on current of the TFET is much lower MOSFETs. The tunneling probability dependent on the bandgap and since silic large bandgap material, the most intu increasing the tunneling current would b bandgap. So, the small band gap materials a annel Length & Oxide T an Asymmetric SGOI ndia S. B ECE Department sb@n a asymmetric SGOI V DD = 0.5 V. Here, length and oxide ing figure of merit ct of gate dielectric GOI-TFET is also and it is found that elative permittivity used for various sult with the record verage subthreshold Swing (SS); High-K- uantum Tunneling. e basic build block y reduction in the one to another ents in switching CMOS chip. With hip power density ow power standby the conventional hreshold swing is d thus inhibits the pply voltage. To equired which can n the conventional alternative device pply voltage and ative device can y lower voltage as Ts are the quantum rrier injection via steep subthreshold of this steep slope, than conventional is exponentially on is a relatively uitive method of be to reduce the are used to achieve an increase in the on current such as Ge, SiGe, III-V etc. tunneling probability. In othe materials reduce the tunneli tunneling barrier [6-7]. To redu enhancing the lateral electri junction is critical. TFETs w proposed which achieves sma high I ON /I OFF ratio and steepe SiGe based technology replace increase leakage current i.e. the leakage current heterostructure used [12-14]. Here, we used th the high I ON with low power su In this paper, we demonstra on Insulator (SGOI) based Germanium as source. Basic discussed in section II. The pr are discussed in section III. Se the novel two-dimensional SG The effects of increased rel dielectrics are also shown whic II. PHYSICS OF TUNNEL F TFET is a semiconductor devic source-drain current through th tunneling. It is the process in valance band to condition ba forbidden energy band gap. T source, gate and drain (as sho consist of a highly doped p reg with an undoped region in betw [15]. The underlying mechani transistors are also known as B For this reason, the device is transistor. Fig.1. TFET d Thickness -TFET Baishya t, NIT Silchar, India nits.ac.in [2-5].Small band gap materials are proposed to improve the er words, these low band gap ing distance by lowering the ucing the tunneling distance and ic field across the tunneling with Germanium as source are all tunneling distance, high I ON , est subthreshold swing [8-11]. es the silicon with Si 1-x Ge x that e off state current. To reduce the e-based area scaled devices are he SiGe technology to maintain upply voltages. ated a novel Silicon-Germanium single-gate (SG) TFET with c principle of Tunnel FET is oposed device and its operation ection IV discussed the result of OI based TFET for Single gate. ative permittivity of the gate ch enhance the ON current. FIELD EFFECT TRANSISTOR ce in which the gate controls the he modulation of Band-to-Band that electrons tunnel from the and or vice-versa, through the TFET has three terminals like wn in Fig.1). The gated diodes gion and a highly doped n region ween and are called p-i-n diodes ism of these gated p-i-n diode Band-to-Band tunneling (BTBT). s called the tunnel field effect device structure.