Aug. 21, 2001 – Kalispell, MT – Semitool Inc. has received two US patents for a novel technology capable of reducing the cost of semiconductor manufacturing by eliminating expensive chemicals, reducing cycle times, and decreasing water consumption. The patents, numbers 6,267,125 and 6,273,108, are for applications and systems using ozone and water for cleaning and stripping semiconductor substrates.
The Semitool process, HydrOzone, offers an environmentally benign, less expensive alternative to traditional chemical cleaning and stripping, the company said. The process uses a unique approach to maximize the effectiveness of ozone as a cleaning agent. Cleaning and stripping processes are necessary to several steps in the semiconductor manufacturing process. Those processes commonly use harsh, costly chemicals to remove contaminants from the surface of the semiconductor wafer. Semitool is marketing its patented ozone-water process to replace these harsh and expensive conventional chemicals.
Semitool’s HydrOzone process delivers ozone to the surface of the semiconductor wafer in a gaseous form, either by direct injection to the process chamber or by a carrier liquid with low ozone solubility. Ozone gas then diffuses through a thin boundary layer of liquid on the surface of the wafer, combining with liquid media on the surface to aggressively remove contamination. The liquid is typically delivered at above ambient temperatures to enhance the effectiveness of the process.