Molecular design and development of photoresists for ArF excimer laser lithography

Positive-tone and negative-tone resists for ArF excimer laser lithography a re developed from novel polymers, which are called functionally-integrated polymers having polar alicyclic units. The fundamental unit of the polymers is an acrylate having a tetracyclododecane group with a carboxyl end group , which satisfies a lot of the requirements of ArF resists. A typical monom er is carboxy-tetracyclo[4.4.0.1(2,5).1(7,10)]dodecyl methacrylate. In 1996 , we established 0.15-mum "positive" line-and-space patterns at 21.8 mJ/cm( 2) using an ArF exposure system (0.55 numerical aperture), which meet the d esign rule requirement for fabricating 1-gigabit dynamic random access memo ries (DRAMs). This fundamental ploymer unit has also been used to develop n egative-tone resists for ArF lithography. In 1999, we also established 0.13 -mum "negative" isolated line pattern at 7.1 mJ/cm(2) using an ArF exposure system which fulfills the design rule requirement for logic circuits combi ned with gigabit DRAMs. Copyright (C) 2000 John Wiley & Sons, Ltd.