Comprehensive Analysis of Duty-Cycle Induced Degradations in HfxZr1-xO2-Based Ferroelectric Capacitors: Behavior, Modeling, and Optimization

This work systematically studies degradations in HfxZr1-xO2 (HZO)-based ferroelectric (FE) capacitors (FeCaps) under pulses with different duty cycles (DCs): 1) a larger drop in the switchable polarization (Psw) and shift in the coercive voltage (Vc) by duty-cycling are observed when compared with conventional endurance and retention tests; 2) through physical modeling, the wider spread of the generated oxygen vacancies (Vos) during duty-cycling leads to stronger domain pinning and the formation of a larger built-in field ($E_{\text{bi}}$), which explains the above observation; 3) optimizations through engineering the stack and composition of the HZO FE layer are proposed and validated on 128Kbit 2T2C FeRAM chips.