Research On The Measurement System Of Non-contact Decay For The Micro/Nano Structure Size

In recent years,the advanced manufacturing industry is of great development,the application of micro-nano precision component is more and more popular,and its surface morphology and related size measurement has become a hot research in the field of ultra-precision measurement.The measurement of the micro-nanostructure size not only includes the measurement of the structural cycle size,but also the measurement of line with and its height.At present,all over the world,ultra-precision surface morphology detection technology is relatively mature,but its function is relatively simple.which can not been taken into account of the measurement accuracy and measurement range.In order to solve the limitation of the single measurement method,combined with the advantages and disadvantages of the current mainstream of white light interferometry and confocal measurement technology,a set of non-contact micro-nano structure size measurement system is built by the principle of compact part common optical path structure,the main research topics are as follows:(1)The design and hardware selection of the optical system,scanning and positioning system and image acquisition system of the measurement system are analyzed by combining the essential principle of white light interference and confocal measurement.(2)According to the characteristics of white light interferometry and confocal measurement,the corresponding control system is designed,including system initialization control,scanning positioning control and scanning acquisition control,and realized the coordinated control of each subsystem of the system.(3)A new interference fringe recognition algorithm and three-dimensional reconstruction algorithm are proposed.The effective separation of the back points and the foreground points is realized by the interference fringe recognition algorithm,which provides the basis for the judgment of the upper and lower limits of the white light interferometry.The three-dimensional reconstruction algorithm uses the idea of surface cutting body which can be simplified to the processing of the triangular mesh by establishing the three-dimensional data field.(4)Using the two measurement modes of the system,the longitudinal step height and transverse line width of the standard template of the step standard measured by the nano-measurement system are measured respectively.The measurement results show that the system integrates the white light interference measurement system and the confocal measurement system,The accuracy of the measurement is high and the repeatability is good,which solves the limitation of the single measurement mode when measuring the surface size of the microstructure.