PROPERTIES OF INTERFACE STATES AT TA2O5 N-SI INTERFACES/

Properties of interface states at Ta2O5/n-Si interfaces are studied by capacitance-voltage and deep-level transient spectroscopy (DLTS) meas urements. The results-show that the ''slow'' states at Ta2O5/n-Si inte rfaces are not significantly affected by annealing, and their density is about 1.4-1.9 X 10(11) cm(-2). The energy distribution of the ''fas t'' interfacial states in the band gap of silicon is obtained, and som e high concentration interfacial states are found. DLTS spectra reveal that the interfacial defects at Ta2O5/n-Si interfaces are all donor t ype. The high concentration interfacial defects are located at about 0 .40 eV below the conduction-band minimum of silicon. Their density dec reases with increasing annealing temperature. The origin is suggested to be related to the diffusion of tantalum into the Si substrate. (C) 1998 American Institute of Physics.