NachhaltigAngewandte Naturwissenschaften und WirtschaftsingenieurwesenTAZ Spiegelau
Beitrag (Sammelband oder Tagungsband)
F. Erber, Günther Ruhl, R. Dietrich, J. Mathuni, P. Nesladek
Development and characterization of a new plasma etching process for mask manufacturing
Proceedings of Photomask and Next Generation Lithography Mask Technology VIII (September 2001; Kanagawa, Japan), vol. Vol. 4409
CD uniformity and CD mean to target specifications nowadays can only be accomplished by mask manufacturing process using chrome dry etch. Chrome plasma etch processes tend to show a strong dependency of the chrome etch rate and thus the etch bias on the clearfield percentage of a mask resulting in varying offtarget behavior. There are various possibilities to compensate for this loading effect. In previous work the methods of using exposure dose and development time for offtarget control were investigated. In this study we examined the capability of plasma etch parameters to be used for offtarget control. The effects of oxygen concentration, pressure and overetch percentage on etch bias and CD uniformity were experiment. Two different development processes were investigated. The resulting offtarget control model was then confirmed by running additional masks at three different clearfield percentages. Measurement results showed a high confidence level for the model predicted numbers. SEM images confirmed stable behavior of chromium sidewall angles.