Compatibility of HfN Metal Gate Electrodes With Hf0.5Zr0.5O2 Ferroelectric Thin Films for Ferroelectric Field-Effect Transistors

Compatibility of hafnium nitride (HfN) electrodes with Hf0.5Zr0.5O2 (HZO) ferroelectric thin films was investigated for ferroelectric field-effect transistor (FeFET) applications. It was found that HZO thin films capped by HfN top electrodes offer improved ferroelectric properties and lower leakage current densities compared to HZO thin films capped by TiN top electrodes. Moreover, FeFETs with HfN/HZO (10 nm)/SiO2 gate-stacks showed a fast write speed of 100 ns, a large 10-year extrapolated memory window (MW) of 0.92 V, and a moderate MW of 0.5 V after 10(4) program/erase cycles. This letter represents a first attempt to fabricate high-performance FeFET memory devices with a fully hafnium-based gate-stack.