| 摘要 |
PURPOSE:To avoid an occurrence of flaws by conducting abrasion for a protective film which is formed after a water repellent process is performed for the rear side of a workpiece. CONSTITUTION:An Si wafer is placed in an atmosphere containing HMDS (hexamethyl disilazane). A hydrophilic groupe existing on the rear of the wafer is converted into a hydrophobic one so that the surface has water repellency. After that, the wafer is fixed on a rotary plate by suction with the surface up. Then, liquid paraffin wax is dropped on the center of the Si wafer. With the rotary plate rotating, a uniform protection film is formed in a short period of time. After dried naturally, the film is sticked by vacuum suction to a working-and-pressing plate for performing abrasion of its surface at high temperature and pressure. By this method, a very strong protection film is gained. Therefore, even if the Si wafer is processed at high temperature and pressure, the protective film can avoids contamination of the back of the wafer caused by the use of an abrasive and occurrence of flaws. |
