Phase change materials (PCMs) have shown significant potential for realizing reconfigurable and non-volatile photonic integrated circuits (PICs). This thesis focused on integrating thin films of the low-loss PCM Sb2S3 with silicon photonic components to enable compact tunable devices. A fabrication process was developed to integrate high-quality Sb2S3 films with SOI waveguides and characterize its reversible amorphous-crystalline phase change. Photonic designs leveraging the pronounced refractive index modulation of Sb2S3 upon phase switching were proposed, including tunable directional couplers and phase shifters with integrated contacts for electrothermal actuation. Short-loop experiments optimized key steps like PCM lift-off and selective etching. Ellipsometry extracted the optical constants of the Sb2S3 films, confirming the refractive index change between phases.