In this study, the periodic purge process of the silicon nitride oxide deposition chamber was quantitatively analyzed and optimized using a real-time contaminant particle sensor (RTCPS). The RTCPS can measure the particle number concentration emitted from the semiconductor process chamber at the foreline in real time. The previous periodic purge process, which used a cycle purge method alternating between showerhead flow on and off, only expelled the accumulated particles in the chamber during the early stages of each cycle. On the other hand, by adding heater movement during the cycle, continuous particle emission was achieved throughout the periodic purge, resulting in improved efficiency. Additionally, the purge time was reduced, leading to increased productivity.