| 摘要 |
PURPOSE:To realize a simpler, higher-precision method of rating for a semiconductor wafer by a method wherein the reflection ranging wide in intensity of a wafer surface is digitized and the resultant numbers are used to standardize the degree of the light transmitting feature of the wafer. CONSTITUTION:A white light from a light source 1 is converted into a monochromatic light in a spectroscope 2 and then penetrates a GaAs specimen 3 after passing through a gap provided in a detector 4 measuring the light reflected from the surface of the specimen 3. The light is then detected by the detector 5 after penetrating the specimen 3. The detector 5 sends out signals that are supplied to a recorder 7 and digital voltmeter 8 after passing through an amplifier 6. Reflection from the specimen 3 detected by the detector 4 is supplied to a digital voltmeter 9 and used to standardize the light displayed by the digital voltmeter 8 after passing through the specimen 3. Real-time rating of the specimen 3 is possible when a data processing system 10 with a display is provided. A system using an optical band-pass filter instead of the spectroscope 2 is also acceptable and is lower in price. |
