Introduction: The opto-electronic characteristics of Zr-doped HfO2 have been thoroughly investigated by many researchers, yet further research is needed to fully understand these materials. To improve the electrical and optical characteristics of Zr-doped HfO2 films, experiments involving novel structures are crucial. The analysis of various characteristics of Zr?Hf1−?O2/Al/Zr?Hf1−?O2 trilayer thin-films are still under consideration.
Methods: In this study, Zr?Hf1−?O2/Al/Zr?Hf1−?O2 trilayer thin-films have been deposited with different substrate temperatures varied from 25 to 300◦C using magnetron sputtering. The trilayer film has been deposited on n type silicon substrates to examine structural and electrical properties. The purpose of depositing the trilayer film on commercial glass substrates is to investigate its optical properties. Zr and HfO2 targets were co-sputter deposited to form the top and bottom layers of Zr?Hf1−?O2. Using a pure Al target, dc sputtering was used to deposit the intermediate metal layer. Various techniques such as grazing incidence x-ray diffraction, field emission scanning electron microscopy, atomic force microscopy, cross-sectional transmission electron microscopy, and energy-dispersive x-ray spectroscopy were employed for structural analysis. UV–VIS spectroscopy has been employed to investigate optical characteristics of the films. The MOS structure with gate electrodes of 100 μm was fabricated using UV photolithography followed by electron beam evaporation technique. Capacitance–voltage and current–voltage measurements were conducted to evaluate the electrical characteristics of the trilayer thin films.
Results: Physical characterization indicates that increasing the substrate temperature enhances the crystallinity, grain size, and surface roughness of the trilayer thin films. The trilayer thin-film, deposited at 300◦C, exhibits enhanced optical transmittance across 400 to 1100 nm wavelength. Furthermore, this film exhibits excellent performance in terms of figure of merit, leakage current, and breakdown performance.
Conclusions: These qualities suggest that the films deposited at 300°C hold potential for application in optoelectronic devices.
