Ultradense One-Memristor Ternary-Content-Addressable Memory Based on Ferroelectric Diodes

In this Letter, for the first time, one-memristor (1M)-based ternary-content-addressable memory (TCAM) with an ultradense 4F2 cell area is proposed on a single reconfigurable TiN/hafnium zirconium oxide (HZO)/indium gallium zinc oxide (IGZO)/TiN ferroelectric (FE) diode. By modulating the FE-polarization-controlled Schottky junction that exists at the interface, reconfigured P–N, N–P, and ohmic like junctions of the FE diodes were designed for ‘0’, ‘1’, and ‘X’ storage states in the TCAM cell, respectively. In addition to non-volatile FE polarization for data storage, ambipolar-like behavior induced by the symmetrical junction characteristics was obtained on the diodes for searching queries. Using both non-volatile and ambipolar-like characteristics, typical TCAM functions with a maximum driving on/off ratio of ~500 were confirmed experimentally on a single FE diode, indicating the great potential of this memory device in area-efficient artificial intelligence processors.