| 摘要 |
PROBLEM TO BE SOLVED: To provide a manufacturing method of the diffraction grating in which no wall-shaped projection is caused. SOLUTION: This manufacturing method comprises: a first stage forming a metallic layer 2 on a substrate 1, further forming a pattern 3 having a first level on the metallic layer 2 and thereafter etching the uncovered parts of the metal layer 2 with the pattern 3 to the substrate 1; a second stage removing the pattern 3 and thereafter etching the exposed parts of the substrate 1 from the metal layer 2 to prescribed depth to form first grooves 5 that become the first level; a third stage forming a pattern 7 slightly longer than a second level, on the metal layer 2 and the first grooves 5 and thereafter etching the uncovered parts of the metal layer 2 with the pattern 7 to the substrate 1; and a fourth stage removing the pattern 7 and thereafter, etching the exposed parts of substrate 1 from the metal layer 2 to prescribed depth to form second grooves 8 that become the second level. By repeatedly performing the above third stage and fourth stage, the objective blazed diffraction grating having (n) levels can be manufactured. |
