| 摘要 |
PURPOSE:To easily form an antireflection film on the surface of a substrate regardless of the kind of the substrate by etching a thin film consisting of plural materials formed on the substrate by microwave plasma CVD method to make it porous. CONSTITUTION:An antireflection film 1 is formed on a glass sheet (ns=1.53) as the substrate 2 as follows. Namely, the surface of the substrate 2 is ultrasonically cleaned by neutral detergent and acetone. The film of a mixture of SnO2 3 and SiO2 4 is then formed on the surface of the substrate 2 in about 1mum thickness by microwave plasma CVD method. The film forming conditions are shown in the table. The obtained sample is then etched by aqua regia for about 5min. In this case, the SnO2 3 having a high etching rate is progressively etched, but the SiO2 4 having a low etching rate is hardly etched. Consequently, a porous layer 5 is formed on the surface of the antireflection film 1 in about 0.9mum thickness. |
