By analysis of the response of a high-contrast photoresist to sinusoidal illumination, generated interferometrically, one can extract a phenomenological modulation transfer function of the resist material, thereby characterizing its spatial resolution. Deep-ultraviolet interferometric lithography allows the resist response to be quantified at length scales below 100 nm. As an example, the resolution (FWHM) of the commercial resist UVII-HS is found to be approximately 50 nm. This simple method can be applied to materials under development for advanced photolithography with short-wavelength illumination.
© 2002 Optical Society of America
J. A. Hoffnagle, W. D. Hinsberg, M. I. Sanchez, and F. A. Houle, "Method of measuring the spatial resolution of a photoresist," Opt. Lett. 27, 1776-1778 (2002)