Low-Temperature Fabrication (≤150 °C) of High-Quality Sputtered Silicon Oxide Thin Film with Hydrogen Plasma Treatment

Abstract

Low-temperature fabrication of thin-film dielectrics is essential for various applications including flexible/stretchable electronics, monolithic three-dimensional integrated circuits, and large-area sensors/displays. Silicon dioxide is one of the most extensively used dielectric materials, but conventional deposition methods such as plasma-enhanced chemical vapor deposition and atomic layer deposition require relatively high temperatures. In this study, a high-quality SiO2 thin film was fabricated at low temperatures below 150 °C using sputtering and hydrogen plasma treatment. The sputtered SiO2 thin film exhibited low leakage current (3 × 10–7 A/cm2 at 3 MV/cm) and a high breakdown field (11.33 MV/cm). After hydrogen plasma treatment was carried out under optimized conditions, the interface trap density between Si and sputtered SiO2 was minimized to 7 × 1011 cm–2 eV–1, which is comparable to the corresponding value for thermally grown SiO2. The results of X-ray photoelectron spectroscopy and secondary-ion mass spectroscopy confirmed that the hydrogen treatment effectively passivates dangling bonds and reduces the portion of oxygen-deficient species.