| 摘要 |
PURPOSE:To obtain a high-precision resist pattern, repetitively by coating in >=2 times a positive type resist rising in the speed with which exposed parts are dissolved in a developing solution as solvent resistance is enhanced by heat treatment, and forming laminated resist layers by heat treatment. CONSTITUTION:When a positive type resist pattern used for fabrication of the integrated circuits of semiconductors is formed, a methyl cellosolve acetate solution of a copolymer of tertiary butyl methacrylate and methyl methacrylate in 35-65 weight ratio is coated on the surface of a heatoxidized film 2 on a silicon substrate 1 to form a resist film 3a, and then it is prebaked in the air at 250 deg.C for 1hr. Further, the same solution is coated on the film 3a to form a film 3b and it is prebaked at 230 deg. in nitrogen for 1hr. These resist films are exposed to electron beams in a desired pattern, and a resist pattern is obtained by developing it with ethyl acetate or the like, thus permitting the lower layer 3a to be made higher in developing speed than the upper layer 3b, and the resist in a vertical or reversely tapered shape to be easily formed, and accordingly, a micropattern to be obtained with high precision. |
