| 摘要 |
PURPOSE:To use a secondary diffraction grating relatively easy to produce and to obtain a primary diffraction grating easily by forming a diffraction grating having a periodical ruggedness on a semiconductor substrate and using a resist applied to recessed parts as a mask to etch the substrate and forming a ruggedness of a half period. CONSTITUTION:A diffraction grating 2 of a prescribed period (400Angstrom ) is formed on a semiconductor substrate (InP)1 by a photolithograph technique using two- luminous flux interference exposure. A diluted photoresist 3 is applied onto the substrate 1 to fill only valley parts. This photoresist 3 is used as the mask to etch the substrate 1, and the resist 3 is melted and removed to form a diffraction grating 4 of a half period. Thus, the diffraction grating relatively easy to produce is used to obtain the diffraction grating of a half period easily. |
