A New Contactless Method to Characterize Electrical Transport Using Eddy Current Fluctuations
Abstract
We describe a new contactless method of characterizing the transport properties of majority carriers in semiconductors which is based on the resistance seen by a small eddy current probe. Unlike the standard eddy current measurement where the probe resistance yields only the sheet resistance of the sample, we can separate the sheet resistance into its constituent parts: the sheet carrier density and the carrier mobility. By using a probe several micrometers in size or less, statistical fluctuations in the number of carriers contributing to the eddy current become significant. This number fluctuation gives rise to a corresponding fluctuation in the observed probe resistance. We can independently deduce the sheet carrier density from the amplitude of the resistance fluctuation spectrum and the carrier mobility from its linewidth. We will present details on the eddy current probe design and the measurement technique. Because this method is contactless and because it does not use the Hall effect nor magnetoresistance to obtain the mobility, it is potentially useful in areas where a standard Hall measurement would be difficult, such as measurements of epitaxial layers in the middle of growth, of magnetic materials and of quantum confined systems where the Hall effect has been suppressed.
- Publication:
-
APS March Meeting Abstracts
- Pub Date:
- March 1997
- Bibcode:
- 1997APS..MAR.C1213C