The factor affecting LWR & sensitivity in EUV resist material

It is well known EUV lithography is the most promising technology for next generation lithography. ITRS roadmap predicts that EUV lithography will realize 22nm half pitch node and beyond. However, there are a lot of problems such as light source power, exposure tools, mask blank defect and resist material for realizing of EUV lithography. Among these problems, we try to develop the high performance resist material for EUV lithography in this paper. EUV resist material are to achieve the Resoultion <= 22nm half pitch L/S, Line Width roughness <= 1.2nm, Sensitivity <= 10mJ. The major development issue of EUV resist is how to simultaneously achieve high sensitivity, high resolution, low LWR. Especially, LWR is the main issue among above RLS performances. So, we decided to choose the polymer bound PAG as resin platform for EUV resist material. Thus, we have studied in various ways to know the relation between LWR reduction and resin physical properties which represents substituted ratio of acid-cleavable unit, Mw, Pd. Additionally, we studied the effects of steric hinderance of pending group with diversifying the size of pending group to make polymer of high performance. We also attempt to know how is LWR affected by hydroxy group species. In this paper, we will show and discuss the results of these studies obtained by tools of e-beam and EUV.