Challenges for Planarizing Organic Antireflectives: Universal Resist Compatibility and Void-free Via Fill

摘要

The design and applications of a planarizing via-fill 248 nm antireflectant coating are shown. New advances now allow for universal resist compatibility (good lithographic performance with both ESCAP- and acetal-based resist chemistries.) This was accomplished by the use of additives which allow the film surface acidity to be adjusted to match the resist's needs through optimization of the antireflectant cure temperature. Simultaneously, advances in antireflectant design have minimized past problems with "void" or "bubble" defects in small via-fills by reducing the amount of antireflectant reflow from intra-via regions into the via during the bake. Experiments are described to characterize via fill performance as a function of bake time, via size, duty ratio and antireflectant nominal coating thickness. A statistical model of the results found antireflectant thickness and the via duty ratio to be the most significant factors.