Nanocrystalline zinc-oxide-embedded zirconium-doped hafnium oxide for nonvolatile memories

Memory devices containing nanocrystalline ZnO-embedded Zr-doped HfO(2) high-k dielectric film have been prepared and characterized. The memory effect was manifested by the large counterclockwise capacitance-voltage hysteresis, e.g., 1.22 at +/- 6 V gate bias, and negative differential resistance region in the positive bias current-voltage range. The maximum trapped charge density of 6.43 x 10(12) cm(-2) was obtained after -9 -> +9 -> -9 V sweep voltage range. The memory effects were mainly caused by electron trapping at low bias voltage. A large memory operation window, e.g., 0.90 V, with a long charge-retention time, e.g., >36,000 s, was achieved under the proper gate-stress voltage. It is a viable dielectric for future nanosize metal-oxide-semiconductor field-effect transistors and capacitors. (c) 2008 The Electrochemical Society.