Effect of using a resin coating on KrF chemically amplified positive resists

摘要

We tried several resins to protect chemically amplified positive resists from contaminants such as ammonia and amines. Polymethyl silsesquioxane (PMSS), a hydrophobic resin, significantly reduced the severity of T-tops and improved delay-time stability. Polyolefinic resin (POR) was the most effective hydrophobic resin and improved the performance of all chemically amplified resists we tried. The pattern profiles were not significantly affected by the protective resin thickness; resin films from 400 angstroms to 9500 angstroms were equally effective. We also used resin coatings to identify when resists are contaminated. We found that contamination begins just after exposure and continues to the end of postexposure bake (PEB).