A coherent multiple imaging technique for use in optical microlithography was studied. The technique involves placing a thin Fabry–Perot etalon between the mask and the projection lens of an optical stepper. An optical lithographic computer simulation tool, Prolith/2, was used to evaluate the aerial image profile obtained for extended mask structures such as typical contact hole arrays and line–space patterns used in integrated circuit fabrication. Additionally, a set of experimental studies were performed to validate the simulation results. Enhancement of both resolution and depth of focus can be obtained simultaneously with appropriate etalon parameters.
© 2000 Optical Society of America
(070.6110) Fourier optics and signal processing : Spatial filtering
(100.2980) Image processing : Image enhancement
(110.4190) Imaging systems : Multiple imaging
(110.4850) Imaging systems : Optical transfer functions
(110.5220) Imaging systems : Photolithography
Miklós Erdélyi, Zsolt Bor, William L. Wilson, Michael C. Smayling, and Frank K. Tittel, "Enhanced optical microlithography with a Fabry-Perot-based spatial filtering technique," Appl. Opt. 39, 1121-1129 (2000)