Adaptive Optics Integrated Surface Roughness Measurement of Sputtered PT Film on Silicon Substrate

Abstract

A new optical inspection system for in situ surface roughness measurement of sputtered Pt film on silicon is developed. In this study, we present an in‐process measurement of surface roughness by combining an optical probe of laser‐scattering phenomena and adaptive optics (AO) for aberration correction. The aim of this study was to demonstrate the necessity for AO compensation in regions containing turbulences. Measurement results of eight Pt film on top of P‐type silicon wafer samples with a roughness ranging from 58 to 83 nm demonstrate excellent correlation between the peak power and average roughness with a correlation coefficient (R2) of 0.9963. The proposed AO‐assisted system is in good agreement with stylus method and less than 0.70% error values are obtained for the aforementioned average sample roughness. The proposed system can be used as a rapid in‐process roughness monitor to further improve the stability of thin film–sputtering processes in situ. © 2013 Wiley Periodicals, Inc. Microwave Opt Technol Lett 55:2055–2059, 2013

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