A high performance trench gate tunneling field effect transistor based on quasi-broken gap energy band alignment heterojunction

Abstract

In this paper, a tunneling field effect transistor based on quasi-broken gap energy band alignment (QB-TFET) is proposed and investigated by simulation method. To offering high on-state current, InGaAs/GaAsSb heterojunction with quasi-broken gap energy band alignment is applied to QB-TFET to improve the band-to-band tunneling rate. Trench gate structure and InGaAs pocket layer are applied to further increase the tunneling efficiency. To suppress the leakage current caused by the off-state tunneling path from source to drain, an intrinsic InGaAs spacer is inserted between n+ InGaAs drain and p+ GaAsSb source. In order to further improve the control ability of gate voltage on channel, TiO2 is used as the gate dielectric of the proposed QB-TFET. Moreover, the effect of x and y fraction of InxGa1-xAs and GaAsySb1-y on quasi-broken gap tunneling junction are studied in this work. The electrical characteristic change of QB-TFET with different x and y fraction is analyzed. The proposed QB-TFET is compared with other works and shows an obvious advantage on performance. As a result, a large on-state current (Ion) of 921µA/µm can be obtained with steep average subthreshold swing (SSavg) of 4.9mV/dec.

A Novel L-Gate InGaAs/GaAsSb TFET with Improved Performance and Suppressed Ambipolar Effect

“…Figure 12c shows the characteristic curves of f T and GBW versus Vg at V d = 0.5 V. Benefiting from structural advantages, such as L-shaped channel and source, the HJTFET obtains the most outstanding frequency characteristics compared with others [21][22][23][24][25][26][27][28][29][30][31][32]. As shown in Figure 12b, the f T and GBP of the HJTFET reached the maximum values of 68.3 GHz and 7.3 GHz under the condition of V d = 0.5 V, respectively.…”

“…To further improve the ON-state current, multimaterial heterojunction engineering is applied to improve the band-to-band tunneling rate [20]. Compared with conventional homojunction TFET, research shows that HJTFETs have superior performances, such as Si/SiGe heterojunction [21][22][23][24], SiGeSn/GeSn heterojunction [25], and III-V heterojunction [26][27][28][29][30][31][32]. By selecting appropriate materials to form heterojunction, on the one hand, the height and thickness of the tunneling barrier can be effectively reduced.…”

Negative differential transconductance in conventional heterojunction TFET

“…Due to its advantages of low sub-threshold swing, high on-current, and compatibility with existing CMOS technology, heterojunction TFET (HTFET) has garnered significant attention and research over the past decade [1][2][3][4] There has been experiments that showed the attractive results in HTFET, such as in Ref. [5], they reported the on-state characteristics in p type HTFET featuring a peak transconductance of 90 μS/μm at drain to source voltage of −0.3 V. On the other hand, extensive researches have also been conducted on the two phenomena based on quantum mechanical tunneling, i.e., negative differential resistance (NDR) and negative differential transconductance (NDT) [6][7][8], since the devices exhibiting NDT or NDR hold significant promise for various applications, including low-power inverter logic, memory systems, and high frequency filters [9,10].…”

An accurate analytical surface potential model of heterojunction tunnel FET

“…The fabricated III-V heterostructure TFET (H-TFET) with a lateral tunneling junction has demonstrated excellent performance with sub-thermal operation, reaching down to 48 mV/decade, and a high current of 10.6 µA/µm at drain-to-source bias of 0.3 V. [4] The TCAD predicted III-V H-TFET with a trench gate and InGaAs pocket structure achieves simultaneously 921 µA/µm on-current and average subthreshold swing of 4.9 mV/dec. [5] Despite significant experimental and finite-element simulation efforts, [4][5][6][7][8][9][10][11][12] an accurate analytical model of the TFET is urgent and indispensable to provide further insight into the physics of the device and to accelerate the process of device and circuit designs. Furthermore, the potential model is the cornerstone of the capacitance and current models, [13,14] which thus needs to be modeled more accurately.…”