| abstract |
Using a two-layer photolithography method, a first photoresist layer, which is a lower layer functioning as a protective layer and a filter layer, is formed on the upper surface of the substrate, and a groove is formed on the substrate by performing FIB etching. A second photoresist layer is formed on the surface of the first photoresist layer with high precision, and the second photoresist layer defines a plurality of high-precision photoresist patterns. The patterns include a pattern for displaying an area to be etched, a target reference mark, and a pattern functioning as a reference mark for alignment. [Selection diagram] FIG. |