High-spatial-resolution semiconductor characterization using a microwave eddy current probe

We report on the design and application of a high-resolution microwave eddy current probe that consists of a microfabricated coil with inner and outer widths of 6 and 20 mum, respectively, integrated with a coplanar waveguide. In addition to improved spatial resolution, we implement a stub-matching technique, which enables us to make high-sensitivity measurements. We demonstrate the utility of our device by measuring the minority-carrier lifetime in a thin In0.53Ga0.47As film. Although our present demonstration does not allow us to reuse the sample, with minor changes this technique can be made noncontact and nondestructive. (C) 2001 American Institute of Physics.