基于ANSYS的HFCVD金刚石厚膜的热应力分析

金刚石膜中的热应力会削弱金刚石薄膜与基底之间的粘结强度和金刚石膜的机械性能,更严重的会使CVD膜产生热裂纹甚至出现"炸膜"现象.本文根据HFCVD金刚石膜沉积过程中实际工作状态的边界条件,通过有限元软件ANSYS计算分析HFCVD金刚石膜中的热应力分布,并通过实验进行了验证,获得了HFCVD膜中热应力的分布规律以及金刚石膜半径、厚度、沉积温度和冷却速度四项实验条件对热应力的影响.研究结果表明:热应力沿径向分布是不均匀的,在边缘部分有突变;金刚石膜的膜厚,冷却速度和沉积温度对金刚石膜中的热应力影响很大,而金刚石膜的半径对膜中热应力影响较小,从而为HFCVD金刚石膜中热应力的预测与控制提供依据.

Study on the Thermal Stress of CVD Diamond Thick Film based on ANSYS

The thermal stress in diamond films will weaken the mechanical and adherence behavior of the diamond film.According to the boundary condition of practical working state,the distribution of the thermal stress in HFCVD diamond film is calculated by ANSYS and verified by experiments.The result is that the distribution of thermal stress in diamond film is non-uniform,and has a break on edge.The paper studies the effects of the four parameters:radius,films thickness,temperature and cooling velocity on the thermal stress.The result shows that films thickness,temperature and cooling velocity have a great influence on the thermal stress but radius is not.All results provide the basis for estimating and controlling the thermal stress of diamond film.