Method and apparatus for forming an optical multilayer filter

• Main Authors: UEHARA, NOBORU, NISHIDA, EMIKO
• Format: Patent
• Language: English; French; German
• Published: 02.01.2003
• Edition: 7
• Subjects: CHEMICAL SURFACE TREATMENT; CHEMISTRY; COATING BY VACUUM EVAPORATION, BY SPUTTERING, BY ION IMPLANTATIONOR BY CHEMICAL VAPOUR DEPOSITION, IN GENERAL; COATING BY VACUUM EVAPORATION, BY SPUTTERING, BY IONIMPLANTATION OR BY CHEMICAL VAPOUR DEPOSITION, IN GENERAL; COATING MATERIAL WITH METALLIC MATERIAL; COATING METALLIC MATERIAL; DIFFUSION TREATMENT OF METALLIC MATERIAL; INHIBITING CORROSION OF METALLIC MATERIAL OR INCRUSTATION INGENERAL; MEASURING; MEASURING ANGLES; MEASURING AREAS; MEASURING IRREGULARITIES OF SURFACES OR CONTOURS; MEASURING LENGTH, THICKNESS OR SIMILAR LINEARDIMENSIONS; METALLURGY; OPTICAL ELEMENTS, SYSTEMS, OR APPARATUS; OPTICS; PHYSICS; SURFACE TREATMENT OF METALLIC MATERIAL BY DIFFUSION INTO THESURFACE, BY CHEMICAL CONVERSION OR SUBSTITUTION; TESTING

In a film forming method for forming an optical multilayer filter by detecting the thickness of each layer by means of an optical thickness monitor (OTM) 15 and by controlling a film forming apparatus 11 based on the OTM detected output: the light source of the OTM 15 is formed by a variable wavelength light source whose wavelength is variable over the range of lambda 1 nm to lambda 2 nm, including X nm; the optical thickness of each of lambda /4-oriented layers is optimized within the range of lambda 1/4 nm to lambda 2/4 nm; the wavelength of the variable wavelength light source 12 for each layer is selected so that its transmittance reaches an extreme value at the optical thickness of each layer; and the formation of each layer is stopped upon detection of the extreme value of the transmittance.