Study On Several Key Technologies Of Measuring The Surface Profile Of Microstructures At Large Scale

Geometrical characteristics parameters and the composition device performance of the microstructure are closely related. With the development of science and technology, more and more functions of the micro device are achieved by micro-structure array. The size of each functional unit is usually in the sub-millimeter level. However the overall size of the micro-structure made up of thousands of the functional unit is in the millimeter or centimeter level. Therefore, not only the range of micro device surface topography measurement is required to be above the millimeter level, but also the spatial resolution of the measurement is required to be micron level, or even sub-micron level.In this paper, we mainly focused on the research of the key technology of image mosaic. The major works in this paper are following:1. We have analyzed the image mosaic method. Based on the characteristics of the surface topography measurement, we have proposed a implementation of image mosaic in the wide range measurement of the surface topography of micro-structure.2. We have studied on the key technology of image mosaic, which includes auto-focusing method of interference images, phase unwrapping algorithm selection, the alignment method of there-dimensional position of sub-regional surface topography and the analysis and selection of sub-regional mosaic path, etc. We have carefully studied the theory of Fast Auto-Focus and determined the focus evaluation function and focus search strategy.3. We have established the Linnik interferometer optical microscopy experimental system. We have wrote automated measurement and control software which improves the efficiency of the system of measurement.4. Focusing on the key technology we have carried out the proposed experiment research, including: experiment verification of the auto-focus method, reliability evaluation of surface topography measurement using step-height standard, the measurement of micro mirror array surface topography and evaluation of the geometry parameters, the measurement of MEMS devices surface topography and comprehensive verification of the proposed measurement method and system feasibility.