Sign-changing non-monotonic voltage gain of HfO2/Parylene-C/SrTiO3 field-effect transistor due to percolative insulator to two-dimensional metal transition

TL;DR

This paper investigates the non-monotonic voltage gain behavior in SrTiO3-based FETs caused by a percolative insulator to 2D metal transition, combining experiments and numerical modeling to understand and predict the phenomenon.

Contribution

It introduces a numerical model that explains the non-monotonic voltage gain in SrTiO3 FETs and verifies predictions through experiments, advancing understanding of 2D metal transitions.

Findings

Observation of non-monotonic voltage gain with negative and positive slopes

Numerical model reproduces experimental results and explains the physics

Predictions of device behavior verified experimentally

Abstract

Controlling the insulator-to-2D-metal transition is a promising key to overcome the scaling problem that silicon-based electronic devices will face in the near future. In this context, we examine the channel formation of SrTiO3-based solid-gated field-effect devices in which a 2D metal phase coexists with a semiconductor phase. A non-monotonic voltage-gain transfer characteristic with negative and positive slope regions is observed. We introduce a numerical model that helps to rationalize the experimental findings in terms of the established physics of field-effect transistors and percolation. Our numerical study not only reproduces the experimental results but also provides non-trivial predictions, which we verify experimentally.