Si Doping in Amorphous GaOx Films via Plasma-Enhanced ALD for Dielectric and Optoelectronic Applications

Ga2O3 is a representative next-generation wide-bandgap semiconductor. Si doping in Ga2O3 plays a crucial role in optimizing performance and expanding applications. Among the synthesis and doping techniques of gallium oxide thin films, plasma-enhanced atomic layer deposition (PEALD) is particularly prominent owing to its high conformality, exceptional uniformity, and atomic-level compositional precision. In this study, a series of amorphous Si-doped gallium oxide (Si-GaOx) thin films with controlled stoichiometries were fabricated by PEALD and systematically characterized in terms of surface morphology, chemical composition, structural and optical properties. Furthermore, the electrical and photoelectric behaviors of the films were evaluated using metal–insulator–semiconductor (MIS) structures and photodiodes. By correlating subcycle ratio modulation with Si concentration gradients, we identified the optimal doping level for enhanced functionality. These findings demonstrate the potential of PEALD-derived amorphous Si-GaOx thin films in dielectric and optoelectronic applications.