| 摘要 |
PURPOSE:To prevent a side-etching as well as to smoothen corner sections by a method wherein an isotropic etching processing and a non-isotropic processing are cojointly performed as a compound etching method. CONSTITUTION:A silicon nitride film 2 of approximately 1.2mum is formed on the surface of a silicon substrate 3 using a vapor-phase growing method and the like, and a silicon oxide film 1 of 0.2mum or thereabouts is formed on the surface of the film 2. Then, a prescribed photoresist film is formed on the surface of the silicon oxide film 1, and a master pattern is obtained by performing an etching on the silicon oxide film 1. The silicon nitride film 2 is etched to the middle part using thermal phosphoric acid, and then the remaining part of the silicon nitride film 2 is removed by performing a reactive etching using CF gas. Accordingly, the silicon nitride film 2 can be etched as per master pattern, the corner of the pattern edge is steppingly formed, and a smooth sectional form can be obtained. |
