Characterization of safe solvent PMMA resist variables for electron-beam a

摘要

Abstract: Results are presented from a study undertaken to evaluate resist casting solvent composition and molecular weight variation in PMMA for electron beam exposure. PMMA cast in several solvent systems have been evaluated for lithographic performance. Additionally, formulations in chlorobenzene with minor variations in molecular weight have been evaluated for batch-to-batch uniformity. A 10 KeV MEBES electron beam system has been used to study resist sensitivity, contrast, and process latitude. Using a two-factor, three level factorial designed experiment, prebake and development time have been varied as controlled process factors. Samples with varying molecular weights were shown to have wide process latitude. These samples gave comparable performance while their molecular weights varied from 539 K to 614 K, and polydispersity varied from 3.3 to 6.1. Resist samples with chlorobenzene, PGMEA (propylene glycol monomethyl ether acetate), and anisole as the casting solvent resulted in equivalent performance. !2