Unlocking potential: Exploring Al2O3:ZrO2:HfO2 ternary composite oxides for advanced dielectric applications

We present an innovative dielectric layer composed of a ternary oxide composite, including high-k materials Al2O3, ZrO2, and HfO2. These composite films were deposited using the Chemical Beam Vapor Deposition (CBVD) technique with a combinatorial approach. We investigated their structural, nanostructural, morphological, and electrical properties for three different Al:Zr:Hf atomic concentrations (∼27:61:12), (∼44:42:13), and (∼67:20:12), which are normalized as AZH (2.2:5:1), AZH (3.3:3.2:1), and AZH (5.5:1.6:1), respectively. X-ray diffraction (XRD) and Raman spectroscopy revealed cubic phase Al2O3 and monoclinic phases of ZrO2 as well as HfO2 in all AZH films. X-ray photoelectron spectroscopy (XPS) showed +3, +4, and +4 oxidation states for Al, Zr, and Hf, respectively. Transmission electron microscopy (TEM) images demonstrated a uniform, dense morphology with no signs of interdiffusion. Among the films, the AZH (5.5:1.6:1) sample exhibited the lowest leakage current density (∼4 × 10−11 A/mm2 at 10 V) and the highest capacitance density (∼15 fF/μm2 at 100 Hz). These results suggest that the proposed dielectric layer has significant potential for advanced applications requiring high capacitance and low leakage.