Physical and electrical properties of hafnium-zirconium-oxide films grown by atomic layer deposition

Abstract

We deposited HfO2, ZrO2, and ZrxHf1-xO2 films having different ZrO2 contents on Si substrates by atomic layer deposition at 300 degrees C and investigated their physical and electrical characteristics. The HfO2 and ZrO2 films with thicknesses of about 20 nm exhibited crystalline structures composed of monoclinic and tetragonal phases, respectively. As the ZrO2 content in the hafnium-zirconium-oxide was increased, the ratio of the tetragonal phase seen in the crystal increased. These changes in crystal phase led to changes in electrical properties. The crystalline phases and electrical properties of the hafnium-zirconium-oxide films exhibited a strong dependence on their Hf/Zr composition ratio.