Photoresist spray coating for resist film performance of deep silicon cavities

In this paper, we describe a new method for resist performance with a photoresist spray coating system. The system consists of a high-temperature rotational chuck, an ultrasonic spray nozzle module, an angle control module, and a nozzle moving module. The spray coating system utilizes several parameters, including solid content, dispensed volume, the scanning speed of the spray nozzle, and the wafer dimensions. In order to prepare samples for photoresist spray coating, the process starts with a thermal oxidation at a thickness of 1000 angstrom. Silicon oxide is used as a masking layer for anisotropic wet etching, 50 mu m and 100 mu m in depth. Photoresist spray coating consumes much less photoresist than conventional spin coating, and the resist uniformity of the deep cavities is more efficient.