Oxide and interface trap densities estimation in ultrathin W/La2O3/Si MOS capacitors

Abstract A novel interpretation for conductance spectra obtained by conductance method of La 2 O 3 gated MOS capacitors has been proposed. Two distinct peaks, one with broad spectrum ranging from 10 k to 200 kHz and the other near 1 kHz with a single time constant spectrum, have been observed at depletion condition. The former spectrum can be assigned as the interface traps ( D it ) located at the interface between La-silicate and the Si substrate by statistical surface potential fluctuation model. On the other hand, as the latter slow trap signal shows strong influence with the thickness of La-silicate layer, it can be assigned as the trappings ( D slow ) at the interface between La 2 O 3 and La-silicate. Finally, the D it and D slow trends on annealing temperature are summarized.