Fabrication of high-quality sol-gel thin films at low-temperature and low-cost is becoming a necessity to realize the full potential of flexible and printed electronics. In this study, we demonstrate a solution-processed metal-oxide-semiconductor (MOS) capacitor deposited on a heavily doped p-type silicon substrate by employing a multilayer dielectric stack of HfO2/Y2O3. The fabrication of the dielectric films was carried out using fast and low-temperature photoactivation treatment under deep-ultraviolet (DUV). Structural and optical properties of multilayers were systemically examined showing the amorphous structural phase with high optical transmission. Electrical measurements of the DUV photoactivated MOS capacitors showed comparable electrical properties to conventional high-temperature thermal annealing. These included a dielectric constant of 10.81 (at 100 kHz), a high areal capacitance of 89.49 nF/cm2 and a low leakage current of ~10−9 A/cm2.