Ferroelectric Field-Effect Transistors Based on WSe₂/CuInP₂S₆ Heterostructures for Memory\nApplications

Abstract

Emerging\ndata-intensive applications need to process data in situ\nby combining the logical operations and data storage in a single chip.\nIn this work, the high-quality bulk CuInP₂S₆ (CIPS) and WSe₂ crystals were synthesized by the chemical\nvapor transport method, with the ferroelectric properties of the CIPS\nflakes proven by piezoresponse force microscopy and electrical polarization–voltage\n(<i>P–V</i>) measurement. We then fabricated ferroelectric\nfield-effect transistors (FeFETs) based on WSe₂/CIPS heterostructures\nwith a buried-gated architecture, which exhibited a clear clockwise\nhysteresis loop with an on/off current ratio exceeding 10⁵ in transfer characterization. More than 100 endurance cycles and\n50 s of retention were achieved, showing quasi-nonvolatile memory\ncharacteristics. Additionally, a memory ternary inverter circuit of\na WSe₂ FeFET serially connected to a MoS₂ FET\nwas fabricated, in which the three logic states (1, 1/2, and 0) could\nbe clearly observed and voltage hysteresis characteristics with a\nmemory window equal to that of a WSe₂ FeFET were achieved.\nThese results pave the way for the realization of integrating data\nstorage with low-power logic on a single chip.