First Implementation of Edge-Contacted α-In2Se3 Ferroelectric Semiconductor Field-Effect Transistors and their Application to Artificial Heterosynapse

Abstract

α-In2Se3, a 2D van der Waals ferroelectric semiconductor, is a promising channel for advanced nonvolatile memory devices such as ferroelectric semiconductor field-effect transistors (FeS-FETs). However, prior studies have largely overlooked the critical influence of source/drain (S/D) contact configurations on memory performance. Here, an edge-contact configuration is demonstrated for the first time in α-In2Se3 FeS-FETs that mitigates strong Fermi-level pinning via 1D interface pinning dipoles and modulates the initial Schottky barrier height (SBH). This novel design preserves coupled ferroelectricity, enhancing the ferroelectric resistance switching ratio by up to 2.33-fold and the memory window by 1.35-fold. These improvements result from SBH modulation and elimination of interference from incompletely switched upper α-In2Se3 layers. The results provide insight into contact-dependent ferroelectric behavior and establish a framework for next-generation neuromorphic computing and artificial heterosynaptic transistors, offering a route for energy-efficient devices.