Effect of Composition Uniformity in the Polymer Chain of EUV Photoresist on Lithographic Performance

Extreme ultraviolet (EUV) lithography is the most promising technology for the fabrication in ultrafine pattern, using 13.5nm light. As CD and pitch sizes of C/H and L/S patterns become tighter, local variations in the resist films are key challenges that must be addressed in EUV photoresists to improve CDU and LWR. Due to the nature of polymer synthetic process for chemically amplified resist (CAR), As a result, differences in composition, molecular weight, and order of polymer chains become significantly more influential. Of these, composition uniformity in the polymer chains of EUV photoresist has been shown to be one of the critical factors for good performance. In this study, polymers with different composition distributions depending on synthetic processes were synthesized and the conversion rate for each synthetic method was monitored. The key properties of their resist films were characterized to identify its effect on resist characteristics. The relationship between structure and EUV lithographic performance will be compared.