Device for measuring change in film thickness

Abstract

Abstract PURPOSE:To detect the change in thickness of a thin film stably based on the magnitudes of respective detected wavelengths, by projecting light having at least three or more wavelengths on the thin film of a material to be measured, and separately detecting the light beams reflected by the thin film for every wavelength. CONSTITUTION:Laser light L1 from an Argon laser oscillator 1, which is oscillated in multiple wavelengths, is projected on a thin film 3, which is coated and formed on a surface 2' on a semiconductor substrate 2. The reflected light from the surface 2' is made to be the reflected light L2, which is prependicular to an external light path by a semitransparent mirror 4. The reflected light L2 is inputted to second and third semitransparent mirrors 5 and 6, and the light beams are inputted to detectors 7 and 8. The light, which is transmitted through the semitransparent mirror 6 is inputted to a detectors 9. The specified wavelengths lambda0, lambda0+DELTAlambda, and lambda0-DELTAlambda of the reflected light L2 are detected by the detectors 7-9. The detected signals are inputted in an operation device 10. Based on the relationship between the magnitudes of the detected wavelengths, the change in thickness of the thin film 3 is measured.

Inventors

• 👤 Yasutomo Fujimori
• 👤 康朝 藤森
• 👤 Akira Ono
• 👤 明 小野

Bibliographic Details