High permittivity thin film nanolaminates

Thin (similar to 10 nm) films comprising of Ta2O5-HfO2, Ta2O5-ZrO2, and ZrO 2-HfO2 nanolaminates were deposited and characterized for possible gate die lectric applications. These films were deposited on silicon substrates usin g atomic layer deposition. The dielectric constants of these films were in 12-14 range and the leakage currents in 2.6 x 10(-8)-4.2 x 10(-7) A/cm(2) r ange at 1 MV/cm electric field. It was found that as these films were made thinner, the value of their dielectric constant dropped compared to their b ulk values. The dominant leakage current mechanism at low electric fields w as determined to be Schottky emission, whereas Poole-Frenkel emission domin ated at higher fields. (C) 2000 American Institute of Physics. [S0021-8979( 00)00404-7].