Ultrashort 15-nm flexible radio frequency ITO transistors enduring mechanical and temperature stress.

Abstract

Flexible radio frequency (RF) transistors play an important role in the fast-growing wearable smart sensors for data communication. However, the scaling capability and high-speed performance of the flexible transistor are far below the counterparts on rigid substrates, impeding the gigahertz high-speed applications. Here, we address the scaling and performance bottlenecks in flexible transistors by demonstrating natively flexible RF indium tin oxide transistors with deeply scaled 15-nm-long channel, capable of operating in the 10-GHz frequency range. The record-high cutoff frequency of 11.8GHz and maximum oscillation frequency of 15GHz can rival those on rigid substrates. Furthermore, the robustness of flexible RF transistors was examined, capable of enduring heavy-duty 10,000 bending cycles at 1-mm radius and extreme thermal stress from cryogenic temperature of 4.3K and high temperature of 380K.