Progress in Resolution, Sensitivity and Critical Dimensional Uniformity of EUV Chemically Amplified Resists

This paper will discuss further progress obtained at Dow for the improvement of the Resolution, Contact critical dimension uniformity(CDU), and Sensitivity of EUV chemically amplified resists. For resolution, we have employed the use of polymer-bound photoacid generator (PBP) concept to reduce the intrinsic acid diffusion that limits the ultimate resolving capability of CA resists. For CDU, we have focused on intrinsic dissolution contrast and have found that the photo-decomposable base (PDB) concept can be successfully employed. With the use of a PDB, we can reduce CDU variation at a lower exposure energy. For sensitivity, we have focused on more efficient EUV photon capture through increased EUV absorption, as well as more highly efficient PAGs for greater acid generating efficiency. The formulation concepts will be confirmed using Prolith stochastic resist modeling. For the 26nm hp contact holes, we get excellent overall process window with over 280nm depth of focus for a 10% exposure latitude Process window. The 1sigma Critical dimension uniformity [CDU] is 1.1 nm. We also obtain 20nm hp contact resolution in one of our new EUV resists.