| 摘要 |
PURPOSE:To enhance plasma resistance and sensitivity without high resolution of a PMMA type resist material by using a copolymer of methyl methacrylate and alpha-methylstyrene as the resist material. CONSTITUTION:A copolymer of methyl or ethyl methacrylate and alpha-methylstyrene is used as a resist material. As the moiety of copolymn., alpha-methylstyrene is preferred from the view points of radiation, such as X-rays or electron beams, decomposability, i.e., the presence of a quternary carbon at the alpha- position, that of an aromatic ring, simple structure, easy availability, and high contrast similar to PMMA. A preferable methacrylate/alpha-methylstyrene copolymn. ratio is 20:80-80:20. Sensitivity of the resist material can be enhanced by coating a substrate with a mixture of said copolymer and a cross-linking agent and cross-linking the copolymer in advance to insolubilize it, then, selectively exposing it to electron beams, or the like to partially decompose the cross-linked parts, and at the time of development, dissolving them with a solvent high in dissolution power to force development. |
