| 摘要 |
PURPOSE:To provide the formation method, of a diffraction grating pattern, wherein the high accuracy of the diffraction grating pattern constituted in a distributed feedback semiconductor laser device or the like is realized. CONSTITUTION:A high-sensitivity resist film and a low-sensitivity resist film are formed on a substrate 1 in this order; they are exposed by a two-light-flux exposure method and developed; after that, a diffraction grating pattern 5a or 5b is formed by an etching operation or an ion implantation operation. |
