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Three-input logic primitives show high efficiency in logic synthesis compared to traditional two-input logic, which encourages researchers to implement three-input logic gates with emerging nanotechnologies. This paper demonstrates a compact implementation of three-input monotone logic gates based on the inverted T-shaped TFET. Firstly, based on the gate coupling mechanism in the novel inverted T channel, the BTBT current can be suppressed in the vertical or horizontal region to achieve the channel strobe. Therefore, the typical three-input monotone logic functions, Majority, OrAnd, and AndOr, are successfully implemented on a single transistor. Then, a simplified potential model describing gate coupling is established to describe the impact of key device parameters on the logic behavior. Combined with TCAD simulation, the design rules of devices with different logic functions are given. Finally, a series of three-input monotonic logic gates are designed and verified. The results show that the use of the proposed TFETs can effectively save the number of transistors in the three-input logic gate, which indicates that the three-input TFET is a compact and flexible candidate for three-input logic gates.

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In this paper, a novel T-channel field effect transistor with three input terminals (Ti-TcFET) is proposed. The channel of a Ti-TcFET consists of horizontal and vertical sections. The top gate is above the horizontal channel, while the front gate and back gate are on either side of the vertical channel. The T-shaped channel structure increases the coupling area between the top gate and the front and back gates, which improves the ability of the gate electrodes to control the channel. What’s more, it makes the top gate have almost the same control ability for the channel as the front gate and the back gate. This unique structure design brings a unique function in that the device is turned on only when two or three inputs are activated. Silvaco technology computer-aided design (TCAD) simulations are used to verify the current characteristics of the proposed Ti-TcFET. The current characteristics of the device are theoretically analyzed, and the results show that the theoretical analysis agrees with the TCAD simulation results. The proposed Ti-TcFET devices with three input terminals can be used to simplify the complex circuits in a compact style with reduced counts of transistors compared with the traditional complementary metal–oxide–semiconductor/ fin field-effect transistors (CMOS/FinFETs) with a single input terminal and thus provides a new idea for future circuit designs.

In this paper, we propose a new type of tri-input tunneling field-effect transistor (Ti-TFET) that can compactly realize the “Majority-Not” logic function with a single transistor. It features an ingenious T-shaped channel and three independent-biasing gates deposited and patterned on its left, right, and upper sides, which greatly enhance the electrostatic control ability between any two gates of all the three gates on the device channel and thus increase its turn-on current. The total current density and energy band distribution in different biasing conditions are analyzed in detail by TCAD simulations. The turn-on current, leakage current, and ratio of turn-on/off current are optimized by choosing appropriate work function and body thickness. TCAD simulation results verify the expected characteristics of the proposed Ti-TFETs in different working states. Ti-TFETs can flexibly be used to implement a logic circuit with a compact style and thus reduce the number of transistors and stack height of the circuits. It provides a new technique to reduce the chip area and power consumption by saving the number of transistors.