Effect of Doping Concentration on Intrinsic Ferroelectric Properties of HfLaO-Based Ferroelectric Memory

With the rapid development of HfLaO ferroelectric films, research on the influence of doping concentration on ferroelectric properties is in urgent need. In this work, we investigated the impact of doping concentration on the ferroelectric properties of HfLaO films based on experiments and first principles calculations for the first time. As the doping concentration increases, the remnant polarization intensity of HfLaO films reaches a maximum at a Hf:La atomic ratio of 15:1. FTJ devices based on HfLaO films demonstrate the ON/OFF ratios up to 92. First principles calculations confirmed that La elements can reduce the energy difference between the o phase and m phase, favoring the formation of the o phase. However, an excessive amount of La elements can lead to the formation of lower valence La-O compounds. This study provides insights into the optimization of ferroelectric devices based on HfLaO films.