Contactless RF methods for measuring electrophysical parameters of semiconductors

We review promising contactless radio frequency (RF) methods for performing localized diagnostics on semiconductors by using quasi-stationary devices. These are resonant systems operating in the frequency range from 100 kHz to 1 GHz that feature high spatial localization of the probe electromagnetic field in small geometrical volumes of the semiconducting samples. A properly chosen operating frequency provides both high spatial resolution and good conversion transconductance for the measured parameter, the detector signal for a wide range of materials with resistivities from 10^–3 to 10⁹ ·cm. We discuss the design of quasi-stationary devices for multiparameter, nondestructive, contactless monitoring of semiconducting ingots, wafers, and structures. We examine methods for measuring resistivity, mobility, and free charge-carrier lifetimes in semiconductors. We describe automated systems and instruments for nondestructive, contactless measurement of parameter distribution over the surface of semiconductor wafers and structures with a spatial resolution of 1 mm. We present the technical specifications of these instruments.V. D. Kuznetsov Siberian Physicotechnical Institute, Tomsk State University. Translated from Izvestiya Vysshikh Uchebnykh Zavedenii, Fizika, No. 9, pp. 45–63, September, 1992.