ORIGINAL PAPER Linearity Performance Analysis Due to Lateral Straggle Variation in Hetero-Stacked TFET K. Vanlalawmpuia 1 & Brinda Bhowmick 1 Received: 6 February 2019 /Accepted: 21 May 2019 # Springer Nature B.V. 2019 Abstract In this paper, we examine the impact of variation in the lateral straggle parameter on linearity and reliability performance for the Hetero- stacked TFET. By incorporating hetero-stack in the Source, both the subthreshold as well as the drain current can be improved. Although the tunnel field effect transistor is considered a valid candidate to replace the MOSFET for low power applications, the device performance depends on the precision in the fabrication process. During fabrication process, ion implantation technique is used to realize the variation in the tilt angle. This variation causes an extension of dopants from the regions of source and drain to the channel, which significantly affects the performance of the device. The linearity and reliability performances of the Hetero-stacked TFET (HS- TFET) are analyzed by varying the lateral straggle parameter (σ) from 0 to 8 nm. A higher value of the lateral straggling parameter causes an increase in the on current due to the enhanced electron tunneling rate. However, linearity performance tends to deteriorate as the lateral straggle parameter increases. The linearity and reliability of the device are studied in terms of transconductances of higher order (g m2 and g m3 ), VIP2, VIP3, IIP3, IMD3 and 1-dB compression point. Keywords Tunnel field effect transistor (TFET) . Heterostacked . Tilt effect . Straggle . Linearity 1 Introduction The tunnel field effect transistor (TFET) is one of the devices that utilizes the injection mechanism of carriers from the source to the channel region depending on the Band-to-Band tunnel- ing (BTBT) which can reach a sub-60 mV/dec subthreshold swing [1, 2]. Furthermore, TFET offers significantly lower off currents and has better immunity to the effects of short channel than the MOSFETs [3]. Although TFET has a high I ON / I OFF ratio, one of the main problems is its low on current state. To overcome this, several architectures were explored such as fully depleted SOI TFET [4], Heterojunction TFET [5], Circular Gate TFET [6], Double-Gate TFET [7], Dual-Material Gate TFET [8], Back-Gate TFET [9], Gate-on-source-only TFET [10]. It is seen that although these devices overcome certain limitations, the subthreshold swing has been degraded im- mensely. Recently, Wu et al. [11] reported a novel structure of TFET, the hetero-stacked source (HS-TFET) and compared with Ge-source TFET and conventional TFET conventional, the HS-TFET obtained a further reduction in the off current and lower average subthreshold swing (SS avg ), given by (V T - V OFF ) / log (I T / I OFF )[12]. During the device manufacturing process, the ion implan- tation process which is used to accurately control the number of doping atoms has become an important technique for the implantation of dopants in the source/drain regions [13]. The effects of channeling on crystalline silicon are avoided by the non-zero tilt. On the contrary, the inclination causes the ex- pansion of the source and the drain regions towards the chan- nel, which reduces the effective length (L eff ) of the channel [14]. The tilt effect is performed using the Gaussian doping profile in the channel source/drain junctions. In sub-100 nm technology node, the performance of the device, as well as its characteristics, are significantly altered due to the variation in the lateral misalignment of the impurity concentration profiles of the implanted ions. Earlier, it has been reported that varia- tion in lateral straggle affects device performance, especially in the analog and RF domain [15–17]. In this work, we study the impact of variation in the lateral straggle parameter on * K. Vanlalawmpuia kpuitea@gmail.com Brinda Bhowmick brindabhowmick@gmail.com 1 Department of Electronics and Communication Engineering, National Institute of Technology Silchar, Silchar, Assam 788010, India Silicon https://doi.org/10.1007/s12633-019-00189-3