| 摘要 |
PROBLEM TO BE SOLVED: To control a depth by making a film to be etched concerning the end point of etching play a role as an etching stopping layer and a taper angle during etching. SOLUTION: As shown in the cross-sectional figure of a substrate S, laminated films A-C comprise a SiO2 film 12 and an Al2O3 film 13 are laminated on a Si substrate 11 200 mm in diameter by a sputtering method, and the substrate S is annealed at 400 deg.C for 30 min in an electric furnace. Moreover, a resist R1 is applied on the surface of the laminated film A, and known patterning is applied (a). Subsequently, the laminated film A of a portion which is not coated with the resist R1 is removed by etching, and part of the SiO2 film 12 of the laminated film B is exposed (b). Next, a resist R2 is applied (c). By repeating dry etching and wet etching, part of the laminated film B is removed, and the resist R2 is exposed so that part of the SiO2 film 12 of the laminated film C (d). Moreover, a resist R3 is applied (e), and by repeating dry etching and wet etching, part of the laminated film C is removed. By peeling off the resist R3, part of the substrate 11 is exposed. In this way, a step-shaped mold for manufacturing an optical element can be obtained. |
