Hassan, Mothana A., Martin, Haydn and Jiang, Xiangqian (2017) Development of a spatially dispersed short-coherence interferometry sensor using diffraction grating orders. Applied Optics, 56 (22). pp. 6391-6397. ISSN 1559-128X

Modern manufacturing processes can achieve good throughput by requiring that manufactured products be screened by better quality control exercised at a quicker rate. This trend in the quality control of manufactured products increases the need for process-oriented precision metrology capable of performing faster inspections and yielding valuable feedback to the manufacturing system. This paper presents a spatially dispersed short-coherence interferometry sensor using diffraction orders of the zeroth and first order for a diffraction grating introduced as a new compact system configuration for surface profile measurement. In this modified design, the diffraction grating acts as the beam splitter/combiner. Diffractions for the zeroth and first orders are represented by the reference and measurement arms, respectively, of a Michelson interferometer, which reduces the optical path length. This innovative design has been proven effective for determining the step-height repeatability in the sensor range from 27 nm to 22 nm for profiles spanning the step heights of the tested specimens.

Mothana_Manuscript_version_Applied_Optics_2017.pdf - Accepted Version

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