Contactless measurement of conductivity of silicon wafers by millimeter waves

Silicon wafers are indispensable materials in the semiconductor industrial fields and have been widely used in various electrical devices. To control the quality of silicon wafers in the process of manufacturing, it is important to measure the electrical conductivity of the wafers. In the present paper, a method to measure electrical conductivity of silicon wafers by using a millimeter wave compact equipment is demonstrated. The principle of technique described here is based on the interaction of millimeter waves with silicon wafers. In order to measure the conductivity of silicon wafers by millimeter waves, a millimeter wave compact equipment was fabricated. This proposed technique is a powerful tool for the measurement of silicon wafers in a contactless fashion, independent of the thickness.