Measurement of surface profile of microstructure

The paper describes the non-contact ultra-high accurate 3D surface profile measuring system for the microstructure, whose surface structure is probably deep and discontinuous. The system is based on the dual-path two-wavelength phase- shifting interferometry and data processing/analysis. To measure the deep microstructure,the generalized two- wavelength measuring method is adopted to expand the depth measuring range. To measure the microstructure whose surface is discontinuous, a new data analysis/processing method is presented, by which the discontinuous surface can be measured without the change of the measuring system. This system has already been applied to measure the surface profile of the various actual microstructures. The results show that the depth resolution of the system is 0.5nm, the depth measuring accuracy is better than 1.3nm. When 20X microscopic lenses is used, the transversal resolution of the system is about 0.5 micrometers , the field is about (phi) 1.325 mm.