Preparation of a Kind of Positive Chemically Amplified Deep UV Photoresist Material with High Sensitivity

With the reaction of poly(4-hydroxystyrene)(PHS) and cyclohexyl vinyl ether(CVE), a partly protected product with acetal groups was prepared. The product PHS-CVE shows good solubilities in common photoresist solvents, high thermal stability and good transparency at 248 nm wavelength. A new kind of positive chemically amplified 248-nm photoresist can be formed by this polymer, disulfone PAG and copolymer of 4-hydroxy styrene and 3-hydroxy-1-adamantyl methacrylate. Lithographic performance was investigated via KrF laser exposure tool. A clear positive-tone pattern with 180 nm line width was obtained under low post exposure bake(PEB) temperature. Poly(4-hydroxy styrene-co-3-hydroxy-1-adamantyl methacrylate) incorporated to the resist can increase the glass transition temperature of the photoresist film, which makes the resist material applicable for 248-nm lithography process.