%A Xue-Li Ma(马雪丽), Hong Yang(杨红), Jin-Juan Xiang(项金娟), Xiao-Lei Wang(王晓磊), Wen-Wu Wang(王文武), Jian-Qi Zhang(张建齐), Hua-Xiang Yin(殷华湘), Hui-Long Zhu(朱慧珑), Chao Zhao(赵 超) %T Crystallization behaviors of ultrathin Al-doped HfO2 amorphous films grown by atomic layer deposition %0 Journal Article %D 2017 %J Chin. Phys. B %R 10.1088/1674-1056/26/2/027701 %P 27701-027701 %V 26 %N 2 %U {https://cpb.iphy.ac.cn/CN/abstract/article_119430.shtml} %8 2017-02-05 %X

In this work, ultrathin pure HfO2 and Al-doped HfO2 films (about 4-nm thick) are prepared by atomic layer deposition and the crystallinities of these films before and after annealing at temperatures ranging from 550℃ to 750℃ are analyzed by grazing incidence x-ray diffraction. The as-deposited pure HfO2 and Al-doped HfO2 films are both amorphous. After 550-℃ annealing, a multiphase consisting of a few orthorhombic, monoclinic and tetragonal phases can be observed in the pure HfO2 film while the Al-doped HfO2 film remains amorphous. After annealing at 650℃ and above, a great number of HfO2 tetragonal phases, a high-temperature phase with higher dielectric constant, can be stabilized in the Al-doped HfO2 film. As a result, the dielectric constant is enhanced up to about 35. The physical mechanism of the phase transition behavior is discussed from the viewpoint of thermodynamics and kinetics.