Exposure tool effects on OPC

Summary form only given. Optical Proximity Correction is essential for modern semiconductor production. The question followed up in this presentation is, how much an imperfection of the exposure tool affects the OPC and ultimately, whether different OPC is needed for different high-end exposure tools. We will focus on modern ArF exposure tools and investigate in particular the effect of lens aberrations and the illuminators effective annularity. For the assessment of the lens aberration effect, lens data taken by PMI as well as LITEL are used. The illuminator is modeled by the standard rectangular profile and a more sophisticated realistic illuminator. This is an aerial image simulation study solely focusing on lines and space patterns. The simulated data are in good agreement as compared with exposure test data. The bulk of simulations were focused on CoG masks, though halftone masks were taken into account. As a result we find, that lens aberrations of modern exposure tools do not force a tool specific OPC, if the lenses fulfill certain quality criteria. Nevertheless it has to be taken special care of spherical aberrations and astigmatism. These aberrations do affect the OPC most strongly. The biggest role for OPC plays the illuminator and here the effective annularity. Illuminator uniformity and the effective sigma should be assessed experimentally to decide on tool specific OPC.