基本信息
摘要：PURPOSE:To measure the thickness of silicon thin film easily with high reliability. CONSTITUTION:A coherent light generating source 2 projects a near infrared light toward a silicon thin film sample 1, where a silicon thin film is formed on a transparent substrate, and a sensor 3 detects the intensity of transmitted light. A light intensity analog signal is delivered from the sensor 3 to an AD converter 5 where it is converted into a digital light intensity signal corresponding to the transmittance of silicon thin film in the silicon thin film sample 1. A CPU 4 then compares the digital light intensity signal with a digital standard light intensity signal corresponding to a standard transmittance prestored in a ROM 6 thus calculating the difference representative of variation of transmittance. A decision is made that the thickness of silicon thin film is acceptable if the variation of transmittance is within an allowable range otherwise it is rejected. Refractive index of silicon thin film can also be measured.
摘要附图：
