Nano-particle laser removal from silicon wafers

Abstract

A laser shock cleaning (LSC) technique as a new dry cleaning methodology has been applied to remove micro and nano-scale inorganic particulate contaminants. Shock wave is generated in the air just above the wafer surface by focusing intensive laser beam. The velocity of shock wave can be controlled to 10,000 mlsec. The sub-micron sized silica and alumina particles are attempted to remove from bare silicon wafer surfaces. More than 95% of removal efficiency of the both particles are carriend out by the laser-induced airborne shock waves. In the final, a removal of nano-scale slurry particles from real patterned wafers are successfully demonstrated by LSC after chemical-mechanical polishing (CMP) process.