沉积时间对钼薄膜结构和热疲劳性能的影响

Influence of Deposition Time on Structure and Thermal Fatigue Property of Molybdenum Film

采用直流磁控溅射在不同沉积时间条件下制备钼薄膜,并用电子束热负荷装置对薄膜进行热疲劳性能试验,利用X射线衍射仪(XRD)对其结构和残余应力状态进行测试分析,用扫描电镜(SEM)对钼薄膜热疲劳前后形貌进行表征。结果表明:薄膜沿(110)取向择优生长,呈柱状晶结构,薄膜内存在张应力,残余应力随沉积时间增加而逐渐减小。热循环试验后均未出现薄膜脱落现象,但均产生表面裂纹。随着沉积时间由4h增加至8h,疲劳裂纹由穿晶断裂的直线裂纹转变为沿晶开裂的曲折裂纹,同时成膜过程中的退火效应使薄膜的晶粒长大、晶粒结构更加趋于完整、残余应力减小,从而使薄膜疲劳裂纹减小。

Molybdenum films were prepared by DC magnetron sputtering method in different deposition times.The fatigue performance of the films was characterized by electron beam thermal cycles load device.The structure,residual stress and morphology of Mo films were analyzed by scanning electron microscope（SEM）and X-ray diffraction（XRD）.The results show that the films preferr orientation（110）with columnar crystal.The tensile stress exists in the films and the residual stress decreases with increasing deposition time.After thermal cycling test,the films do not flake,but crack on its surface.With increasing deposition time from 4hto 8h,the fatigue crack transforms from transcrystalline crack with straight line shape to intergranular crack with wriggle shape.The effect of annealing in the process of film forming,makes the grain size grow,crystal structure more completed,and the residual stress decrease,which reduce fatigue crack of the films.