Novel microwave device for nondestructive electrical characterization of semiconducting layers

A microwave measurement technique, using a novel cell which enables the sheet resistance (R ⧠), the carrier density (n), and the mobility (μ) of epitaxial layers to be measured, is proposed. The system, controlled by a microcomputer, performs this characterization by measuring galvanomagnetic effects. The sample is only lightly pressed on the cell. The electrical contacts between the sample and the cell are capacitive. This method is thus nondestructive and requires no technological process. The data treatment necessitates knowledge of factors which are determined from a calibration procedure made only once. For the GaAs samples reported here, the accuracy is better than 5% for R ⧠, 15% for μ, and 20% for n.