Uniting The Trinity of Ferroelectric HfO2 Memory Devices in a Single Memory Cell

The polarization reversal in ferroelectric HfO ₂ is adopted to store information in three distinct device classes - ferroelectric field effect transistors (FeFET), ferroelectric capacitors (FeCAP) and ferroelectric tunnel junctions (FTJ). Common to all three concepts is the adoption of a ferroelectric layer stack that acts either as gate dielectric in the FeFET or as the capacitor dielectric and tunneling barrier in the FeCAP or FTJ, respectively. A composite structure including an inevitably or purposefully formed dielectric layer is frequently adopted. In this work we report on the co-existence of all three memory concepts within one device structure and propose a 2T1C ferroelectric memory cell that allows the operation and comparative characterization of the trinity of ferroelectric memory devices.