COATING THICKNESS METER AND COATING THICKNESS MEASUREMENT METHOD

PROBLEM TO BE SOLVED: To provide a coating thickness meter and a coating thickness measurement method for precisely controlling coating thickness by improving the S/N ratio of an electric signal determined by measuring the coating thickness of a thin film during film formation without depending on a measurement wavelength. SOLUTION: The coating thickness meter A comprises a light source 10 for projecting light to a substrate, where an optical thin film is formed; a spectroscope 20, where measurement light is guided from the substrate; and a controller 30. The spectroscope 20 comprises a spectral section 21 for dispensing measurement light, and a light reception section 28 having a plurality of photodiodes for photoelectrically converting the luminous flux being dispensed by the spectral section 21 for inducing a light reception current. The controller 30 comprises an exposure time pattern, where exposure time is set for each photodiode, and a means for transmitting a control signal for measuring light reception current output according to the spectroscope 20 according to the exposure time pattern. COPYRIGHT: (C)2004,JPO&NCIPI