Ferroelectric Zr0.5Hf0.5O2 thin films for nonvolatile memory applications.

Authors :: Müller, J.
Böscke, T. S.
Bräuhaus, D.
Schröder, U.
Böttger, U.
Sundqvist, J.
Kücher, P.
Mikolajick, T.
Frey, L.
Source :: Applied Physics Letters. 9/12/2011, Vol. 99 Issue 11, p112901. 3p. 1 Black and White Photograph, 3 Graphs.
Publication Year :: 2011
Abstract: We report the observation of ferroelectricity in capacitors based on hafnium-zirconium-oxide. Hf0.5Zr0.5O2 thin films of 7.5 to 9.5 nm thickness were found to exhibit ferroelectric polarization-voltage hysteresis loops when integrated into TiN-based metal-insulator-metal capacitors. A remnant polarization of 16 μC/cm2 and a high coercive field of 1 MV/cm were observed. Further proof for the ferroelectric nature was collected by quasi-static polarization-voltage hysteresis, small signal capacitance-voltage, and piezoelectric measurements. Data retention characteristics were evaluated by a Positive Up Negative Down pulse technique. No significant decay of the initial polarization state was observed within a measurement range of up to two days. [ABSTRACT FROM AUTHOR]