Laser-induced backside wet cleaning technique for wafers

• Main Authors: Wen-Shiang Peng, 彭 文祥
• Other Authors: Chwan-Huei Tsai
• Format: Others
• Language: zh-TW
• Published: 2014
• Online Access: http://ndltd.ncl.edu.tw/handle/21321070476107108443

碩士 === 華梵大學 === 機電工程學系 === 102 === The aimed of this paper is to propose an alternative technique of laser cleaning for silicon wafer. An Nd:YAG laser was applied from the backside of the wafer which is submerged in water. The laser energy induces shock wave in the wafer. The shock wave transmits into the water and generates a turbulent bubble flow. The shock wave and the bubble flow remove the alumina particles from the surface of the wafer. Because the wafer contacts with the water, the damage due to the laser heat can be significantly reduced. The phenomena of bubble nucleation, growth, and combination were studied. The acoustic emission signal and the bubble flow images during the cleaning process were obtained to analyze the cleaning mechanism. The laser stationary cleaning and laser scanning cleaning were studied. The parameters of laser power, repetition rate, and scanning speed were established. It was found that the optima laser repetition rate is 15 KHz and the laser power needed is less than 50 W. The backside wet cleaning technique was successfully demonstrated for the removal of submicron particles of 0.5 μm in size. The proposed technique has great potential to provide an improved solution for the glass cleaning. Keywords：Laser cleaning, Backside wet cleaning, Laser shock wave, Silicon wafers