ULTRA FINE GROOVED PATTERN FORMING PROCESS

摘要

PURPOSE:To form an ultra fine grooved pattern with excellent reproducibility eliminating any unnecessary ion implantation by a method wherein three processes such as a process to form an etching mask layer with a groove not reaching the surface of layer to be formed, an another process to make the layer to be formed appear on the bottom of groove and the other process to dry-etch the etching mask layer selectively are performed. CONSTITUTION:An etching mask layer 12 with a V-type groove 13 not reaching the surface oa layer 11 to be formed is formed on the layer 11. The distance 14 from the edge of V-type groove 13 to the surface of layer 11 will be the remaining film thickness (h). When the etching mask layer 12 is dry-etched until the surface thereof reaches the level 15, the edge of V-type groove 13 will be slightly rounded. When the layer 12 is further etched until the surface thereof reaches the level 16 with the surface of layer 11 to be formed beginning to appear on the bottom of groove and the etching process is stopped at that time, the bottom of V-type groove 13 is made into an opening with specified opening width 17. The opening width 17 may be extended corresponding to the remaining film thickness (h) i.e. the distance 14 from the edge of V-type groove 13 to the surface of layer 11 to be formed. Therefore, the opening width 17 may be controlled precisely by the remaining film thickness (h).