Influence of Zr Doping on Electrical and Dielectric Properties of Spin-Coated Hafnia Films for CMOS Applications

For the development of next-generation metal–oxide–semiconductor (MOS)-associated devices in the semiconductor industry, there is a need for metal oxide materials with a high dielectric constant (κ). In this study, HfO₂ films were prepared using a cost-effective spin coating method, with Zr doping levels of 2 mol.%, 4 mol.%, 6 mol.%, and 8 mol.%, by depositing on p-type silicon wafers. A comprehensive investigation was conducted after annealing the films at 500°C to analyze the structure, crystallite size, defects, chemical composition, and surface morphology. The Zr-doped HfO₂ films maintained the monoclinic phase with crystallite size of ~32 nm and ~27 nm for the (−111) and (111) planes, respectively, after Zr doping. Further, to determine the electrical properties of the films, capacitors with a MOS configuration were fabricated, and voltage (V) dependence studies on current (I) and capacitance (C) were carried out. From this study, Zr doping at 4 mol.% exhibited the lowest oxygen vacancies (28%), low leakage current (7 × 10⁻⁴ A/cm²), low interface trap densities (0.2 × 10⁹ eV⁻¹ cm⁻²), and a comparatively high dielectric constant κ value (19). This study highlights the potential of synthesized Zr-doped HfO₂ films for device miniaturization using a facile, cost-effective method.