Crystallization behaviors of ultrathin Al-doped HfO2 amorphous films grown by atomic layer deposition  

作　　者：Xue-Li Ma Hong Yang Jin-Juan Xiang Xiao-Lei Wang Wen-Wu Wang Jian-Qi Zhang Hua-Xiang Yin, Hui-Long Zhu Chao Zhao 马雪丽;杨红;项金娟;王晓磊;王文武;张建齐;殷华湘;朱慧珑;赵超(Integrated Circuit Advanced Process R&D Center,Institute of Microelectronics,Chinese Academy of Sciences;University of Chinese Academy of Sciences;National Center for Nanoscience and Technology)

机构地区：[1]Integrated Circuit Advanced Process R ＆ D Center, Institute of Microelectronics, Chinese Academy of Sciences, Beijing 100029, China [2]National Center for Nanoscience and Technology, Beijing 100190, China [3]University of Chinese Academy of Sciences, Beijing 100049, China

出　　处：《Chinese Physics B》2017年第2期461-466,共6页中国物理B（英文版）

基　　金：Project supported by the National High Technology Research and Development Program of China(Grant No.2015AA016501);the National Natural Science Foundation of China(Grant Nos.61574168 and 61504163)

摘　　要：In this work, ultrathin pure HfO_2 and Al-doped HfO_2films（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 HfO_2 and Al-doped HfO_2 films are both amorphous. After550-℃ annealing, a multiphase consisting of a few orthorhombic, monoclinic and tetragonal phases can be observed in the pure HfO_2 film while the Al-doped HfO_2 film remains amorphous. After annealing at 650℃ and above, a great number of HfO_2 tetragonal phases, a high-temperature phase with higher dielectric constant, can be stabilized in the Al-doped HfO_2 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.In this work, ultrathin pure HfO_2 and Al-doped HfO_2films（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 HfO_2 and Al-doped HfO_2 films are both amorphous. After550-℃ annealing, a multiphase consisting of a few orthorhombic, monoclinic and tetragonal phases can be observed in the pure HfO_2 film while the Al-doped HfO_2 film remains amorphous. After annealing at 650℃ and above, a great number of HfO_2 tetragonal phases, a high-temperature phase with higher dielectric constant, can be stabilized in the Al-doped HfO_2 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.

关 键 词：Al-doped HfO2 ultrathin film phase transition thermodynamics kinetics 

分 类 号：O484.4[理学—固体物理]