Translator Disclaimer
14 September 2001 Mechanical analysis of hard pellicles for 157-nm lithography
Author Affiliations +
Potential transmission problems for polymeric pellicle membranes at 157 nm have led to alternative designs incorporating ultra-thin modified fused silica, i.e., so-called 'hard pellicles.' The mechanical characteristics of hard pellicles are unique. Forces can be generated between the pellicle frame and the patterned reticle during bonding because of misalignment and warpage. These forces create out-of-plane distortions of the reticle, which can subsequently induce in-plane distortions. Also, since the hard pellicle is an optical element, its deflection can be a source of error. In addition, because the reticle is rapidly repositioned during exposure, vibration of the pellicle could be excited by stage motion. It is important, therefore to understand the structural and modal response of the composite pellicle / reticle system. Experimental analyses were conducted to determine changes in the reticle and hard pellicle profiles (out-of-plane) due to bonding. Finite element modeling was used to support the experimental study, as well as identify the gravitational distortions of the pellicle. A modal analysis was also performed on the hard pellicle after bonding. The experimental measurements and finite element results were in excellent agreement, both for mode shapes and vibration frequencies.
© (2001) COPYRIGHT Society of Photo-Optical Instrumentation Engineers (SPIE). Downloading of the abstract is permitted for personal use only.
Phillip L. Reu, Andrew R. Mikkelson, Michael P. Schlax, Eric P. Cotte, Lowell K. Siewert, Roxann L. Engelstad, Edward G. Lovell, Giang T. Dao, and Jun-Fei Zheng "Mechanical analysis of hard pellicles for 157-nm lithography", Proc. SPIE 4346, Optical Microlithography XIV, (14 September 2001);

Back to Top