High contact angle embedded barrier layer materials for next-generation 193 immersion lithography

To maximize value in integrated circuit manufacturing, semiconductor manufacturers continually seek materials that enable processing with higher throughput and which provide higher yield. 193nm immersion lithography (193i) has been a mainstay in semiconductor manufacturing for many years. However, 193i throughput is constrained by topcoat layers necessitating additional processing steps, and yield is impacted by defectivity resulting from water droplet interactions with wafer surfaces. To overcome these limitations, a platform of high contact angle embedded barrier layer (EBL) materials was developed and EBL polymers were incorporated directly into advanced photoresist formulations, obviating the need for topcoat, permitting faster wafer scan speeds, and lowering defectivity from water droplet rupture or water leakage during immersion processing. These EBL materials were designed with a built-in solubility switch such that they maintain a hydrophobic surface during scanning but can rapidly solubilize in aqueous base developer and rinse away during development, significantly outperforming previous generation designs. This report will detail the development, evaluation, and optimization of new EBL materials with substantially higher contact angles than previous materials for next-generation 193i applications.