| abstract |
A photoresist underlayer film containing a copolymer of a styrene derivative and a nortricyclene derivative is applied as an antireflection film on a substrate, and a layer of a photoresist composition is applied on the underlayer film to form a patterned circuit region. Forming a resist pattern by irradiating the photoresist with a developing solution to form a resist pattern, and processing the lower film layer and the substrate using a photoresist layer as a mask with a dry etching apparatus. The underlayer film forming material of the present invention has a refractive index n value of 1.5 to 1.9 and a k value of 0.15 to 0.3, and a film thickness of 200 nm or more is sufficient. The extinction coefficient is sufficient to exhibit the anti-reflection effect, and the etching rates of CHF 3 / CF 4 -based gas and Cl 2 / BCl 3 -based gas used for processing the substrate are almost the same as those of the novolak resin, and have high etching resistance. It was also confirmed that the resist shape after patterning was good. [Selection diagram] None |