| 摘要 |
<p>PURPOSE:To solve the problem that apectral characteristics degrade owing to change of properties in reverse etching between glass substrate and filter by providing a heat treatment process. CONSTITUTION:A copper thin film 2 is formed as a metal thin film on a glass substrate 1. Resist 3 is coated thereon and the film 2 is photoetched to stripe form. Next, this substrate 1 is heat-treated particularly at 350 deg.C to 450 deg.C in the state where the reverse etching material does not oxidize such as in a vacuum or inert gas. Thereafter, a dichroic filter 4 is formed on the substrate 1 and film 2. Next, the substrate 1 is dipped in an aqueous FeCl3 solution as the etching solution of the film 2, by which the film 2 and the filter 4 thereon are removed, whereby the dichroic stripe filter is obtained.</p> |
