Modified Linnik microscopic interferometry for quantitative depth evaluation of diffraction-limited microgroove. (11th April 2018)

• Record Type: Journal Article
• Authors: Ye, Shiwei; Takahashi, Satoru; Michihata, Masaki; Takamasu, Kiyoshi
• Is Part Of: Measurement science & technology. Volume 29:Number 5(2018:May)
• Publication Date: 2018-04-11
• Subjects: optical depth evaluation method -- super-resolution technology -- diffraction limited microgroove -- modified Linnik microscopic interferometry; Physical measurements -- Periodicals; Scientific apparatus and instruments -- Periodicals; Equipment and Supplies -- Periodicals; Science -- instrumentation -- Periodicals; Technology -- instrumentation -- Periodicals; Mesures physiques -- Périodiques; Physical measurements; Scientific apparatus and instruments; Periodicals; 502.87
• DOI: 10.1088/1361-6501/aab008
• Languages: English
• ISSNs: 0957-0233

Abstract

Abstract: The quality control of microgrooves is extremely crucial to ensure the performance and stability of microstructures and improve their fabrication efficiency. This paper introduces a novel optical inspection method and a modified Linnik microscopic interferometer measurement system to detect the depth of microgrooves with a width less than the diffraction limit. Using this optical method, the depth of diffraction-limited microgrooves can be related to the near-field optical phase difference, which cannot be practically observed but can be computed from practical far-field observations. Thus, a modified Linnik microscopic interferometer system based on three identical objective lenses and an optical path reversibility principle were developed. In addition, experiments for standard grating microgrooves on the silicon surface were carried out to demonstrate the feasibility and repeatability of the proposed method and developed measurement system.