Authors: J.W. Lee, M.J. Lee and M.Y. Yi
Affilation: Pohang University of Science and Technology, Korea
Pages: 344 - 346
Keywords: nano particle cleaning, cryogenic, supersonic nozzle
Cryogenic particle beam can be an effective means of removing nano-sized contaminant particles from a substrate surface. In order to generate a particle beam of high intensity and controlled size and temperature, Argon gas was expanded through two different types of supersonic nozzle, simple orifice and contoured Laval nozzle. A variety of particle size and velocity was obtained by controlling the stagnation pressure and temperature, the back pressure, and the use of nozzles with differing throat size and expansion angle. The two different types of nozzles showed different characteristics of particle generation. Increased stagnation pressure resulted in an increased particle size with the contoured nozzle, but a decreased size with the simple orifice. The generated particle beam was found to be almost perfect in removing micron and submicron particles, and also quite effective for nano-sized particle. Experiments on the cleaning efficiency with both types of nozzles clearly showed that there exists an optimum bullet particle size corresponding to each contaminant particle size.