Laser Cleaving of Silicon on Insulator (SOI) Wafers to reduce Costof SOI Wafer Manufacturing through elimination of the Chemical Mechanical Processing

"Laserdyne Labs has developed several processes to apply laser technology to manufacturing tasks typically conducted by using mechanical equipment. In the emerging SOI (Silicon on Insulator) field, a present technology (Smart-Cutr) uses a layer of Hydrogenimplanted in the silicon lattice to generate a splitting region between host and handle wafer. The current process is using thermal annealing in an oven. Based on our previous experience in this field we are suggesting utilizing localized laser heatinstead of the broad overall heating of the bonded wafers in an oven. First tests have shown that the process is feasible and is not restricted by geometric boundaries. Cleave planes as produced by the laser can be pieced together without any shift in thedefinition of the cleavage plane. Furthermore, first principle calculations suggest that the higher energy flux rate of the laser can be utilized to reduce the necessary Hydrogen dose, as well as provides more flexibility in terms of various dopant levels.This proposed process would result in lowering the costs of SOI wafers through our simple, more cost-effective process flow. The cleaved wafer surface will be smooth and can be used directly without any post-cleave mechanical polishing or edge treatment. Our work in SOI processing technology is aimed at helping drive down the cost of SOI production so significantly that it will become a mainstream wafer technology. For many years the se