Thin film monitor using laser and film thickness measuring method

Abstract

Abstract PURPOSE:To monitor the film thickness of a thin film up to about 2mum by setting the wavelength of a laser for irradiation to 700-800nm and monitoring variation in the film thickness by multiple light interference effect simultaneously with thin film formation or etching. CONSTITUTION:The semiconductor laser 2 uses an AlGaAs semiconductor laser (oscillation wavelength: 750nm) and its laser light is entered into a vacuum chamber 1 through an incidence quartz window 3 and reflected by a substrate surface 4. At this time, the laser light is varied in intensity by the multiple interference effect and absorption of the thin film. Then this laser light whose intensity varies exits from the vacuum chamber 1 through a projection quartz window 5 and enters a detector 6. The output of the detector 6 is converted by a digital voltmeter 7 into a digital signal, which is sent to a computer 6 for control. Thus, the film thickness of the thin film can be monitored up to 2mum.

Inventors

• 👤 Noboru Otani
• 👤 昇 大谷
• 👤 Kazuhiko Kawamura
• 👤 和彦 河村

Bibliographic Details