| Summary: | This study presents the characteristics of HfAlO films for a series of Al incorporation ratios into a HfO<sub>2</sub> dielectric by atomic layer deposition on a Si substrate. A small amount of Al doping into the HfO<sub>2</sub> film can stabilize the tetragonal phase of the HfO<sub>2</sub>, which helps to achieve a higher dielectric constant (<i>k</i>) and lower leakage current density, as well as a higher breakdown voltage than HfO<sub>2</sub> film on its own. Moreover, assimilation of Al<sub>2</sub>O<sub>3</sub> into HfO<sub>2</sub> can reduce the hysteresis width and frequency dispersion. These are indications of border trap reduction, which was also verified by the border trap extraction mechanism. X-ray photoelectron spectroscopy (XPS) analysis also verified the HfAlO microstructural properties for various Al compositions. In addition, higher amounts of Al<sub>2</sub>O<sub>3</sub> in HfAlO resulted in better interface and dielectric behavior through trap minimization, although the equivalent-oxide-thickness (EOT) values show the opposite trend.
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