TIME-RESOLVED MICROWAVE CONDUCTIVITY MEASUREMENTS FOR THE CHARACTERIZATION OF TRANSPORT-PROPERTIES IN THIN-FILM MICROCRYSTALLINE SILICON

The time resolved microwave conductivity (TRMC) technique measures the transient change in microwave reflectivity that carriers generated by a laser pulse induce in a sample. The reflectivity variation with tim e reflects, combined with the mobility, the carrier generation or reco mbination, either in the bulk or at the interfaces. From the measureme nts, one may deduce the carrier lifetime, and the carrier mobility, ei ther in the bulk or near the interface. Computer simulations, for thin films deposited on glass, has been performed so as to modelize the TR MC transients. The transport properties of various micro-crystalline s ilicon thin films, deposited either with laser annealing technique, or with layer by layer technique, are obtained from TRMC. The results ar e compared with other characterizations. The TRMC mobility is smaller than field effect mobility in micro-crystalline silicon. The TRMC diag nostic can be used for material optimization.