Use of highly absorptive azo dyes in photoresist coatings

Abstract

We recently synthesized and studied a number ofhighly absorptive diketo azo dyes. These materials, existed in the hydrazo tautomeric forms, showed high extinction coefficients, typically c 25,000 -39,000 at 365 nm. They also exhibited good solubility in common resist casting solvents such as propylene glycol monoethyl acetate (PGMEA) and ethyl lactate. The thermostability of the materials was investigated. The impact ofthese diketo azo dyes on i-line resist performance in terms of swing reduction, reflective notching control and lithographic performance will be discussed.