DIFFRACTION OPTICAL ELEMENT AND MANUFACTURING METHOD THEREFOR

摘要

PROBLEM TO BE SOLVED: To provide a method of manufacturing a diffraction optical element having a multi-stage optical structure. SOLUTION: The diffraction optical element is prepared by forming a multilayered structure (10) containing a plurality of amorphous silicon phase shift layers (14 to 20) which have thicknesses selected so that the diffraction optical element can shift the phases of infrared light being within an effective wavelength region. The amorphous silicon phase shift layers (14 to 20) are separated by silicon dioxide etch stop layers (22 to 26) being about 5nm thick or thinner. The individual layers of the multilayered structure (10) are successively masked and etched to form a multi-stage optical structure (34). COPYRIGHT: (C)2004,JPO