This study systematically investigates the influence of hydrogen plasma treatment on indium tin oxide (ITO) thin films deposited via RF magnetron sputtering and subsequently processed by plasma-enhanced chemical vapor deposition (PECVD). A comprehensive characterization of the structural, roughness, optical, and electrical properties was performed employing X-ray diffraction (XRD), atomic force microscopy (AFM), X-ray photoelectron spectroscopy (XPS), UV-visible spectroscopy, and four-point probe electrical measurements. Results indicate a hydrogen flow rate-dependent preferential crystallographic orientation, with higher flow rates promoting the (222) plane concomitant with hydroxyl bond formation and a reduction in oxygen vacancy concentration. In contrast, lower hydrogen flow rates favor the (400) orientation, indicative of oxygen depletion and increased vacancy density. AFM analyses, incorporating statistical, multifractal, and bearing area methodologies, consistently elucidate the evolution of surface morphology and roughness under varying hydrogen plasma exposure. Optical characterization reveals enhanced transmittance and bandgap widening correlated with prolonged hydrogen treatment. Electrical measurements demonstrate a reduction in sheet resistance associated with increased oxygen vacancies during short-duration hydrogen plasma exposure, whereas extended treatments lead to elevated resistance, attributed to charge carrier scattering by hydroxyl groups. These findings elucidate the complex interplay between hydrogen plasma parameters and ITO thin film properties, providing critical insights for tailoring material performance in optoelectronic and transparent conductive applications.
Bastami et al. (Sun,) studied this question.