An In_0.53Ga_0.47As/In_0.52Al_0.48As Heterojunction Dopingless Tunnel FET With a Heterogate Dielectric for High Performance

In this paper, an In <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">0.53</sub> Ga <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">0.47</sub> As/In <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">0.52</sub> Al <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">0.48</sub> As heterojunction dopingless tunnel field-effect transistor (HDL-TFET) with an HfO <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sub> /SiO <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sub> heterogate dielectric is proposed, where the N <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">+</sup> -pocket with variable electron concentration can be formed by adjusting the length of source-side channel (LSC) based on the charge plasma concept, instead of employing conventional ion implantation or dual-material gate techniques. It aims to improve the device performance and simplify the device fabrication. At the drain bias of 0.3 V, numerical simulations show that the on-state current (ION) of the HDL-TFET with LSC = 4 nm can approach ~10 <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">-5</sup> A/μm that is far higher than that of the Si-DL-TFET (~10 <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">-10</sup> A/μm), and the average subthreshold swing (SS <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">avg</sub> ) can approach 36.6 mV/decade that is significantly lower than that of the Si-DL-TFET (89.2 mV/decade). It is also found that the drain-induced barrier lowering (DIBL) effect and the ambipolar current can be effectively suppressed in the HDL-TFET because of an existence of heterojunction. Under the condition of low gate and drain biases, the HDL-TFET exhibits peak values of the cutoff frequency (f <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">T</sub> ) and the maximum oscillation frequency (f <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">max</sub> ) approaching 13 and 4.73 GHz, respectively, while the Si-DL-TFET yields those of 8.05 and 2.26 GHz, respectively, under relatively higher biases. It indicates that the HDL-TFET is a promising device for low-power consumption radio frequency applications.