Grating pitch comparison measurement based on Cr atomic transition frequency and Si lattice constant

Traceability is the fundamental premise of all metrological activities. The establishment of a traceability chain characterized by a shortened structure, while simultaneously enabling on-site traceability, represents a key trend in the advancement of metrology. This study explores the periodic accuracy and overall uniformity of self-traceable gratings, employing multilayer film gratings with a nominal period of 25.00 nm as the medium. We present a comparative analysis of measurement capabilities in a self-traceable grating calibration system characterized by a ‘top-down’ calibration approach and a Si lattice constant calibration system characterized by a ‘bottom-up’ calibration approach. The results indicate that the values obtained for the multilayer film grating periods, calibrated using the self-traceable grating system, are 24.40 nm with a standard deviation of 0.11 nm. By comparing with the values derived from the Si lattice constant, which yield 24.34 nm with a standard deviation of 0.14 nm, the validity and feasibility of the self-traceable calibration system are confirmed. This system extends and complements existing metrological frameworks, offering a precise pathway for traceability in precision engineering and nanotechnology research.