Image Enhancement in High-Resoltuion Lithography Through Polymer Grafting Techniques

A major limitation of high resolution lithography techniques is the throughput, or the ability to create the appropriate image patterns in the resist at high speed. The resist sensitivity to incident radiation is a key factor in limiting the throughput. The authors have explored the use of polymer grafting techniques to obtain image enhancement by increasing the sensitivity of the resist to electrons(l), x-rays(2), ions(3)and deep-UV photons. In this paper we first review the basic grafting process and mechanisms. Then, examples of grafting induced image enhancement are given. Finally, a quantitative comparison is presented for resist sensitivity gains under various irradiations.