Work

Ternary Logic Transistors Using Multi‐Stacked 2D Electron Gas Channels in Ultrathin Oxide Heterostructures

Year: 2024

Type: article

Abstract: 2D electron gas field‐effect transistors (2DEG‐FETs), employing 2DEG formed at an interface of ultrathin (≈6 nm) Al 2 O 3 /ZnO heterostructure as the active channel, exhibit outstanding drive current (≈215 µA), subthreshold swing (≈132 mV dec −1 ), and field effect mobility (≈49.6 cm 2 V −1 s −1 ) with a high on/off current ratio of ≈10 7 . It is demonstrated that the Al 2 O 3 upper layer in Al 2 O 3 /ZnO heterostructure acts as the source/drain resistance component during transistor operations, and the applied potential to the 2DEG channel is successfully modulated by Al 2 O 3 thickness variations so that the threshold voltage (V th ) is effectively tuned. Remarkably, double‐stacked 2DEG‐FETs consisting of two Al 2 O 3 /ZnO heterostructured 2DEG channels with a single gate exhibit multiple V th , enabling a ternary logic state in a single device. By inducing a voltage difference between the stacked channels, a sequential operation of the upper and lower FETs is achieved, successfully realizing a stable ternary logic operation.

Source: Advanced Science

DOI: 10.1002/advs.202410519