Translator Disclaimer
28 May 2004 MEV as a new constraint for lithographers in the sub-100-nm regime
Author Affiliations +
Mask error factor (MEEF) is a commonly used metric in lithography. This parameter gives a good indication of the impact of intra-mask CD variation on the wafer. Unfortunately, MEEF is useless to anticipate the CD variation on the wafer induced by Mask Mean-To-Target variation (MMT). Currently, MMT error is compensated by adjusting the exposure dose. This paper presents the concept of MEV (MEEF Energy-latitude Variation) which is defined by the equation δCDwafer=MEV *δMMT after the dose compensation in a similar way to the MEEF concept. A simple expression for MEV will be presented which shows that the MEV factor is proportional to the variation of the product of EL*MEEF through the population. Using 65nm logic gate level, MEV experimentally shown to be non-zero, and roughly ½ times MEEF factor, which is of course non-negligible in sub 100nm regime. Based on aerial image simulation, pure optical effects are responsible for about 40% of the MEV, which gives a slight predominance of the resist part. Finally, the possibility of reducing the MEV factor by compensating for MTT variation not only by dose but also by illumination settings change is discussed. This will give the basis for an Advanced Process Control (APC) algorithm for the future generations.
© (2004) COPYRIGHT Society of Photo-Optical Instrumentation Engineers (SPIE). Downloading of the abstract is permitted for personal use only.
Yorick Trouiller, Sergei V. Postnikov, Kevin D. Lucas, Frank Sundermann, Kyle Patterson, Jerome Belledent, Christophe Couderc, and Yves Fabien Rody "MEV as a new constraint for lithographers in the sub-100-nm regime", Proc. SPIE 5377, Optical Microlithography XVII, (28 May 2004);

Back to Top