公开(公告)号：JPH07280520A

公开(公告)日：1995-10-27

申请号：JP7223894

申请日：1994-04-11

Applicant: TORAY INDUSTRIES

Inventor： TORIKAI JUN ,  HIRATA HAJIME ,  MOTOCHIKA NAGAKAZU ,  KOJIMA HIDEYUKI ,  YAMAMOTO MICHIYO

IPC: G01B11/02 ,  G01B11/06 ,  G02B5/20

Abstract: PURPOSE:To measure a thickness of a thin film with high accuracy by correcting the effect of distortion spectroscopy intensity of an interference light due to the thin film in accordance with the spectroscopy penetration characteristic of a thin film material. CONSTITUTION:A white measurement light from a light source 11 is emitted on a color filter film 5 with a color liquid crystal to be measured, a measurement light which is reflected thereby to become an interference light is introduced into a spectroscopy section 3 to be separated by a plane diffraction grating 34 so that components in a prescribed wavelength range are focused on an image sensor 36 to form an image 35. An image sensor drive circuit 37 reads an optical intensity of the image 35 by each image to transmit to an operation section 4 via a buffer amplifier 38 as a voltage signal so that the measurement spectroscopy intensity F (lambda) is obtained. A ratio (modulation signal) X (lambda) between intensity F (lambda) and an average spectroscopy intensity G (lambda) that was obtained beforehand by the same measurement order in terms of a plurality of samples with thin films of which kinds are the same as the coating film 5 having different thickness, is obtained, then in the peak values of plural wavelengths (maximum wavelength and minimum wavelength), the thickness is calculated from the adjacent maximum wavelengths or minimum wavelengths.