关键词: 超声雾化喷嘴, 喷涂工艺, 雾锥特性, 液滴输运

Abstract: The photoresist is widely used in integrated circuit and micro electro-mechanical manufacturing systems processes, but traditional spin coating process will loss 95% of photoresist and cause negative environment impact for its high toxicity, which need higher disposing cost. Improving the utilization rate of the photoresist is one of the main objects of the coating process. Based on the self-developed 100 kHz ultrasonic nozzle, the film uniformity problem during the photoresist saving-oriented ultrasonic atomizing spraying process is studied. After analyzing the flow field distribution of carrier gas, a force and collision model is built to study behavioral characteristics of atomized droplets in rotating and symmetrical airflow field and then proposed a numerical simulation procedure to study transport processes of atomized droplets, which could analyze the impact of gas flow, fluid flow and spray cone cross-section height on atomized droplet’s particle size and concentration distribution effectively. The actual ultrasonic atomizing spraying experiment was carried out on 304.8 mm wafer using photoresist AZ4999. The results shows that the ultrasonic atomizing spraying nozzle can achieve high film uniformity and save about 80% photoresist when compared with spin coating process.

Key words: Droplet transport, Spray cone’s characteristics, Spraying process, Ultrasonic nozzle