HfO_2-SiO_2混合膜力学性能

Mechanical properties of HfO_2-SiO_2 mixed films

利用离子辅助电子束双源共蒸发工艺方法,制备了SiO_2掺杂含量分别为0、13%、20%、30%、40%和100%的六组HfO_2-SiO_2混合膜。采用纳米压痕法测量了不同组分混合膜的杨氏模量和硬度,并研究了混合膜杨氏模量和硬度随SiO_2含量增长的变化规律。结果显示,随着SiO_2含量增加,混合膜杨氏模量和硬度均减小,双组分复合材料并联模型可以较好地拟合杨氏模量随混合膜SiO_2含量变化关系。为了解释混合膜力学性能随SiO_2含量变化规律,对混合膜进行了XRD测试,研究了混合膜微观结构与杨氏模量和硬度的关系,发现结晶对硬度影响显著,对杨氏模量影响较小;用Zygo干涉仪测量了样品的面形,获得了薄膜残余应力随SiO_2含量的变化规律,表明SiO_2掺杂能减小HfO_2薄膜压应力。

Six groups of HfO2-SiO2 mixed films with SiO2 content about 0,13%,20%,30%,40%and 100%were prepared using ion-assisted e-beam co-evaporation process separately.The Young′s modulus and hardness of the mixed films with different SiO2 content were measured through nanoindentation,and the variation of Young′s modulus and hardness as a function of SiO2 content were studied.The results show that with the increase of SiO2 content,both the Young′s modulus and hardness of the mixed films decrease,and the variation of Young′s modulus of mixed films as a function of SiO2 content can be well fitted by iso-stress model of a two-component composite.In order to illustrate the relation between SiO2 content and mechanical properties of the mixed films,the microstructure of the mixed films was analyzed by XRD,and the influence of microstructure on Young′s modulus and hardness were studied.It was found that the crystallization of thin films had major impact on hardness,but little influence on Young′s modulus.The residual stresses of the mixed films were calculated using the data of surface shape measured by Zygo interferometer,the variation of stress as a function of SiO2 content was obtained,and a reduction of compressive stress with the SiO2 doped in HfO2 was observed.