Investigation of analog/RF performance of staggered heterojunctions based nanowire tunneling field-effect transistors

In this paper, the analog/RF performance of an III-V semiconductor based staggered hetero-tunnel-junction (HETJ) n-type nanowire (NW) tunneling FET (n-TFET) is investigated, for the first time. The device performance figure-of-merits governing the analog/RF performance such as transconductance (g(m)), transconductance-to-drive current ratio (g(m)/I-Ds), output resistance (R-out), intrinsic gain and unity-gain cutoff frequency (f(T)) have been studied. The analog/RF performance parameters is compared between HETJ NW TFET and a homojunction (HJ) NW n-type TFET of similar dimensions. In addition to enhanced I-ON and subthreshold swing, a significant improvement in the analog/RF performance parameters obtained by the HETJ n-TFET over HJ counterpart for use in analog/mixed signal System-on-Chip (SoC) applications is reported. Moreover, the analog/RF performance parameters of a III-V based staggered HETJ NW TFET is also compared with a heterojunction (HETJ) NW n-type MOSFET having same material as HETJ n-TFET and equal dimension in order to provide a systematic comparison between HETJ-TFET and HETJ-MOSFET for use in analog/mixed-signal applications. The results reveal that HETJ n-TFET provides higher R-out and hence, a higher intrinsic gain, an improved g(m)/I-Ds ratio, and reasonable f(T) at lower values of gate-overdrive voltage as compared to the HETJ NW n-MOSFET. (C) 2015 Elsevier Ltd. All rights reserved.