17 April 1995 New phase-shifting technique for deep UV excimer laser based lithography
Author Affiliations +
This paper reports simulation and experimental details of a novel phase shifting technique based on laser interferometry. Phase shifting is one of the most promising techniques for the fabrication of high density DRAM's. In recent years many kinds of phase shifting methods have been proposed to extend the resolution limit and contrast of image patterns. These techniques however, have several problems that result from the phase shift elements on the mask, especially when applied to UV excimer laser illumination. A new technique will be described that is based on a one-layered reticle which is used as both a reflective and transmissive mask, irradiated from both the front and the back sides. A combination of both off-axis illumination, as well as phase shift are used in the new method. Both the relative path length of the two beams as well as their amplitude can be manipulated in such a way that near 100% contrast can be achieved in the final image. Experimental as well as simulation data are used to demonstrate this new method.
© (1995) COPYRIGHT Society of Photo-Optical Instrumentation Engineers (SPIE). Downloading of the abstract is permitted for personal use only.
Zsolt Bor, Zsolt Bor, Joseph R. Cavallaro, Joseph R. Cavallaro, Miklos Erdelyi, Miklos Erdelyi, Motoi Kido, Motoi Kido, Chaitali Sengupta, Chaitali Sengupta, Michael C. Smayling, Michael C. Smayling, Gabor Szabo, Gabor Szabo, Frank K. Tittel, Frank K. Tittel, William L. Wilson, William L. Wilson, } "New phase-shifting technique for deep UV excimer laser based lithography", Proc. SPIE 2380, UV and Visible Lasers and Laser Crystal Growth, (17 April 1995); doi: 10.1117/12.206950; https://doi.org/10.1117/12.206950

Back to Top