Low-porosity anodic aluminum oxyhydroxide (AlOOH) composite films and thermally sprayed yttrium oxide (Y2O3) films exhibit excellent mechanical strength, chemical corrosion resistance, and high dielectric properties. These characteristics make them promising candidates for applications in the sensor field. Plasma-induced corrosion significantly limits the service life of aluminum components in semiconductor equipment. In this study, we aim to develop a dense, plasma-resistant Y2O3 coating on AA6061 substrates through a hybrid approach. A hard anodic oxide layer was first formed to enhance interfacial bonding and buffer thermal stress. Ground Y2O3 powder was then applied by thermal spraying to form a 200-μm-thick coating. By reducing the deposition rate, the internal porosity was lowered to approximately 2%. Subsequent aerosol deposition further sealed residual pores, achieving a surface porosity below 0.5%. The resulting composite film exhibited enhanced corrosion resistance, thermal stability, and structural integrity under plasma exposure. This integrated process demonstrates potential for scalable, high-performance protective coatings in advanced semiconductor manufacturing environments.