Effects of Process-Induced Defects on Polarization Switching in Ferroelectric Tunneling Junction Memory

The scaling effects of ferroelectric tunnel junction (FTJ) memory are investigated by evaluating remanent polarization (Pr), coercive field (Ec), and polarization switching speed. Through the analysis on dc tunneling currents and frequency responses of Ec and Pr for FTJs with various sizes, it is found that polarization switching mechanism (domain nucleation limit) is not changed by the width reduction. However, by the length scaling, domain wall spreading-limited switching becomes dominant by processinduced damaged edge regions, leading to the larger Pr and the faster switching speed.