Focus position and depth of two-dimensional patterning by Talbot effect lithography
Analytical expressions of the Talbot effect for self-imaging from low-order diffraction rays were derived. The depth of focus based on Rayleighs criterion was analytically a quarter of the Talbot distance. In a hexagonal array of a fine pitch, the Talbot distance derived from 2nd-order approximation was not accurate. The Talbot distance of hexagonal array was derived from the accurate analytical expression.
focus talbot effect lithography hexagonal simulation