Electrical characterization of Ti-silicate films grown by atomic layer chemical vapor deposition

Abstract

Electrical characterization was performed for Ti-silicate films, which were deposited by atomic layer chemical vapor deposition (ALCVD). Before the deposition of Ti-silicate films, the silicon substrates were pretreated differently using hydrofluoric acid (HF)-etching, chemical oxidation, and thermal oxidation. Regardless of the pretreatment methods, the grown films showed a highly smooth surface with rms below 0.52 nm. The electrical properties of the grown Ti-silicate films showed a strong dependence on the substrate pretreatments. The 5-nm-thick Ti-silicate films grown on hydrogen-passivated Si and chemically oxidized Si showed rather high leakage currents, whereas the films grown on thermally oxidized Si showed low leakage currents below I X 10(-7) A/cm(2) at a bias of -I V. All of the films showed a positive shift in the flatband voltage (V-FB) upon annealing. Also, each film showed low a hysteresis below 180mV and the hysteresis decreased upon annealing.