Effect of extreme-ultraviolet pellicle support to patterned mask

Abstract

Extreme ultraviolet lithography is about to be realized in mass production even though there are many obstacles to be overcome. Several years ago, the EUV pellicle was suggested by some people, but the idea of using the EUV pellicle was abandoned by most people because there were big problems that were believed to be almost impossible to overcome. The EUV pellicle should be made of an inorganic material instead of a common organic pellicle and should be very thin due to EUV transmission. In addition to that the support of the very thin pellicle film should be used. The structure of the support of the pellicle thin film should not make any noticeable intensity difference on the top of the patterned mask side. However, the experimental result of the Intel showed the interference images with their suggested support structure. In the Intel's report, the structure of the support was honeycomb or regular mesh type with a ∼ 10 μm line width and a ∼100 μm pitch size. We study the intensity distributions on the top of mask for various combinations around the above the mentioned scales and the support structures. The usable structure of the support will be reported based on our simulation results, which would open the possibility of the EUV pellicle in mass production. © 2012 SPIE.