A Novel Dopingless Ternary FET With the Metal Source for Ternary Inverter Implementation

This article proposes a novel dopingless ternary FET (DLT-FET) composed of the longitudinal metal-source/InAs-channel/InAs-drain structure for compact implementation of the ternary inverter. A single DLT-FET mixes two types of carrier transport mechanisms: 1) according to the concept of charge plasma, the Band-to-Band tunneling (BTBT) can occur at channel/drain interface by metal work function engineering; 2) Schottky Barrier tunneling (SBT) at the source/channel interface. The mechanism of the DLT-FET is verified with the help of TCAD tools. The simulation results revealed that both N/P-type DLT-FETs have a flat drain current characteristic around
V
_G
= 0.5
V
_DD
, where the
V
_G
-independent
I
_BTBT
dominates the drain current. The stable third output voltage can be obtained through the voltage dividing, while both the
I
_SBT
and
I
_BTBT
generate the other voltage levels of 0 V and 1.0
V
_DD
. Furthermore, the effects of a series of key device parameters on DLT-FETs and ternary inverter performance are evaluated. The ternary inverter can be implemented by simply replacing two transistors with N/P-type DLT-FETs in a conventional binary inverter and selecting appropriate device parameters for exhibiting comparable transfer characteristics.