MEASURING DEVICE AND MEASURING METHOD

摘要

PROBLEM TO BE SOLVED: To surely and precisely perform a measurement by forming an insulating film of a material or structure in which the intensity of the transmitted light in the natural absorption wavelength area is a value of a specified ratio of that before transmission when a light containing the wavelength of infrared area is emitted. SOLUTION: A light source 1 emits a light 2 containing the wavelength of infrared area to a sample 3, and the transmitted light 2 is inputted to a detector 5 through a spectroscope 4. The sample 3 is formed of a silicon base 6, a SiO2 film 7 which is an insulating film and a polycrystalline silicon film 8. The sample 3 is placed on a support base 9 used also as electrode, and a variable voltage generating source 10 is provided to apply a bias voltage to the sample 3. When the bias voltage is applied, the absorption peak of Si-O-Si antisymmetric extending and contracting movement of the SiO2 film 7 is shifted on high frequency side. A calculating part calculates the potential difference of the SiO2 film 7 from the thickness of the SiO2 film on the basis of the output of the detector 5. In case of an insulating film other than SiO2 film, measurement is facilitated to the insulating film in which the intensity after transmission of the light 2 containing the wavelength of infrared area is about 1/20 or more of that before transmission.