Effect of SiO2 capping layer on the ferroelectricity of Hf0.5Zr0.5O2 films

In this paper, SiO2 capping layers were introduced to improve the ferroelectric properties of Hf0.5Zr0.5O2 (HZO) thin films. HZO thin films with the SiO2 capping layers exhibit excellent ferroelectric characteristics. The largest remnant polarization (2Pr) was about 35.6 µC/cm2 for the HZO film with the SiO2 capping layer. The remnant polarization was larger than that for the film with the W capping layer after annealing at 550 °C and 600 °C and there was more oxygen content in the film with the SiO2 capping layer.