Focus position and depth of two-dimensional patterning by Talbot effect lithography

• Published in: Microelectronic Engineering Vol. 123; pp. 80 - 83
• Main Author: Sato, Takashi
• Format: Journal Article Conference Proceeding
• Language: English; Japanese
• Published: Amsterdam Elsevier BV 01.07.2014; Elsevier
• Subjects: Applied sciences; Approximation; Arrays; Cross-disciplinary physics: materials science; rheology; Diffraction; Electronics; Exact sciences and technology; Imaging; Lithography; Materials science; Mathematical analysis; Methods of nanofabrication; Microelectronic fabrication (materials and surfaces technology); Nanolithography; Nanoscale pattern formation; Patterning; Physics; Semiconductor electronics. Microelectronics. Optoelectronics. Solid state devices; Surface treatments; Talbot effect; Talbot effect; Microelectronic fabrication; Patterning; Simulation; Lithography; Imaging; Focus; Two dimensional model; Arrays; Hexagonal
• ISSN: 0167-9317
• DOI: 10.1016/j.mee.2014.05.019

The Talbot effect is a self-imaging phenomenon enabling lens-less imaging. The interval of the focus position is called the Talbot distance. To maintain pattern fidelity, the accurate focus position of the self-imaging needs to be known. The depth of focus based on Rayleigh's criterion is analytically a quarter of the Talbot distance. In a hexagonal array of a fine pitch, the Talbot distance derived from 2nd-order approximation is inaccurate. The analytically accurate expression of the Talbot distance for hexagonal arrays is shown in imaging of low-order diffraction rays.