MEMS制造中精确测量薄膜厚度的方法研究与比较

精确测量各种功能薄膜的厚度在微机电系统（ MEMS）制造加工过程中有非常重要的意义。利用接触式表面轮廓仪、光谱椭偏仪、电感测微仪、扫描电镜、原子力显微镜和工具显微镜分别测量了10 nm～100μm各种薄膜的厚度。比较了不同测量仪器的测量范围、分辨率和对样品的适用性，分析了薄膜厚度测量过程中误差产生的机理。实验结果表明：当存在膜层台阶时，10 nm～100μm的膜厚测量均可采用接触式表面轮廓仪，对于硬度较高的膜层可采用电感测微仪，对于厚度小于0.5μm的膜层可采用原子力显微镜；对于可观察样品侧面、厚度大于0.7μm的膜层可采用扫描电镜，工具显微镜适用于μm级膜层，对于厚度大于20μm的膜层不宜采用光谱椭偏仪。

Study and comparision of accurate measurement methods for film thickness in MEMS fabrication

It is very important to accurately measure thicknesses of various functional films during micro-electro-mechanical systems( MEMS)manufacturing process. Various sample films with thickness of 10 nm~100μm are measured by contact surface profilometer,spectroscopic ellipsometer,inductance micrometer,scanning electron microscope( SEM),atomic force microscopy( AFM)and toolroom microscope. The measurement range,resolution and applicability of different measurement equipments are compared,error generation mechanism during thickness measurement is analyzed. Experimental results show that when there is a mesa layer on the substrate,contact surface profilometer can be used for thickness measuring at range of 10 nm~100μm;inductance micrometer is suitable for harder layer;AFM can be used for measuring thickness less than 0. 5μm;SEM is suitable for sample with homogeneous profile and with thickness more than 0. 7μm;toolroom microscope can be used for micro-scale layer;spectroscopic ellipsometer is not suitable for measuring the thickness more than 20μm.