Multi-Layer Anti-Reflection Film Based on SiO_x and NbO_x by DC Pulse Sputter System with Inductively Coupled Plasma Source

The research on anti-reflection (AR) optical thin film has long sought to obtain high-performance reflection and transmission properties in photovoltaic and photonic devices. The study of multi-layer AR (M-AR) film with low- and high-refractive-index materials is essential to increase the selective transmittance and reflectance at visible light wavelengths. However, M-AR film exhibits low substrate adhesion and slow deposition rates. We developed a DC pulse sputter system incorporating an inductively coupled plasma (ICP) source of high density to obtain high-quality M-AR film. Six-layer AR optical thin film was simulated using SiOx as a low-refractive-index material and NbOx as a high-refractive-index material. The multi-layer AR film based on SiOx and NbOx (M-SiNb) was fabricated using DC pulse sputtering which incorporated an ICP source. M-SiNb film exhibited better properties than the optical simulation results at 550 nm (transmittance: 99.19%, reflectance: 0.87%). Similarly, the M-SiNb film fabricated using the ICP source had high transmittance and reflectance in the visible light region and excellent adhesion to the substrate notwithstanding the various mechanical tests it was subjected to. Consequently, the development of the DC pulse sputter system included the ICP source, and this study represents important research in the field of optical film.