Development of APSM resists for sub-200 nm contact holes

This paper focuses on using the resist contrast curve as a method for pre-screening resists for attenuated phase-shift mask contact hole applications. The importance of surface inhibition and high c-value in developing PSM C/H resists is revealed. These concepts are confirmed by lithographic evaluation. A good overall process window (without sidelobe printing) is demonstrated by such high c-value resists.