Silicon-containing resists for 157 nm applications

We have designed and developed an aqueous base soluble polymer system with a silsesquioxane (SSQ) backbone for 157 nm bilayer resist applications. These base resins have absorbances as low as 0.6 μm-1 at 157 nm. The imagable polymers which contain acid-labile ester functionalities have absorbances between 2.0 and 3.0 μm-1. The silicon content of these polymers is around 15% by weight. Therefore, our polymers can be utilized in 157 nm positive bilayer resist applications with a film thickness of around 150 nm. We have evaluated several resist formulations based on these polymers. These resist formulations have shown high contrast and excellent resolution. © 2001 SPIE - The International Society for Optical Engineering.