Ternary Logic Circuit Based on Negative Capacitance Field-Effect Transistors and Its Variation Immunity

A multivalued logic (MVL) device can achieve greater data density with a smaller footprint than a traditional binary logic device. In this study, a ternary logic inverter based on negative capacitance FETs (NCFETs) without additional footprints has been realized. By enhancing the amplification in surface potential owing to the utilization of the negative capacitance, the third intermediate state can be successfully obtained at V
_DD
/2 in the conventional binary CMOS inverter. The third intermediate state arises due to no-saturation effect of drain current, and the noise margin of the third intermediate state (NM
_M
) can be optimized by changing ferroelectric thickness or annealing temperature of ferroelectric material. The influence of remnant polarization ( P
_r
) and coercive electric ( E
_C
) variation on the ternary logic inverter was investigated based on experimental data. Moreover, a ternary logic 8T SRAM with transmission gate logic (TGL) was proposed, and the results show that the proposed 8T SRAM cell exhibits nondestructive read and reliable write operations for all three states.