There is an increasing necessity to use supersmooth surfaces, and quantitative Characterization of surpersmooth surface with roughness in the sub-nanometer range plays an important role in the controlling the super-polishing process and raising the final surface quality. So it is necessary to improve the methods of measuring and specifying the highly smooth optical surfaces. The estimating system based on the Power Spectral Density (PSD) function is introduced in this paper, including the basic theory and the physical meaning. Two kinds of supersmooth surface, isotropy and anisotropy, are measured by optical profiler and the topographies are gotten. Then PSD curves calculated from the discrete profile data and light scattering properties are discussed in detail. Furthermore, optical profiler and AFM are adopted to test the same sample with different measurement parameters to investigate the PSD analysis method. Eventually a polynomial is fitted to the data sets in an extanted spatial frequency domain, 10μm^-1~12.8μm^-1, including low frequency, mid-frequency, and high frequency band. Although the frequency response of the instruments and the scanning area can affect the test results, the results can still be compared with each other directly using the PSD. The research gives a powerful support to selecting appropriate measurement instrument and parameters in the interested frequency regime during the surface test, which is useful at controlling and giving feedback on the fabrication of supersmooth surface.

Date Published: 20 May 2009
PDF: 6 pages
Proc. SPIE 7283, 4th International Symposium on Advanced Optical Manufacturing and Testing Technologies: Optical Test and Measurement Technology and Equipment, 72830B (20 May 2009); doi: 10.1117/12.828590

Published in SPIE Proceedings Vol. 7283:
4th International Symposium on Advanced Optical Manufacturing and Testing Technologies: Optical Test and Measurement Technology and Equipment
Yudong Zhang; James C. Wyant; Robert A. Smythe; Hexin Wang, Editor(s)