Patent ID: 6100167
Filing Date: 2000-08-08
Classification: H01L

Abstract:
A process for preparing a boron dosed silicon wafer having a polished surface wherein copper, present on the polished surface and in the wafer interior, is removed to prevent the formation of a haze on the polished surface with the passage of time, the process comprisingpolishing a surface of a boron doped wafer, the polishing process contributing copper to the surface and interior of the wafer,annealing the polished wafer at a temperature of at least about 75.degree. C. for at least about 30 seconds to increase the concentration of copper on the polished surface of the wafer and decrease the concentration of copper in the interior of the wafer, andcleaning the polished surface of the annealed wafer to reduce the concentration of copper thereon,the concentration of copper in the interior of the annealed and cleaned wafer being reduced during the annealing step such that the concentration of copper on the polished and cleaned surface of the wafer will not increase by a factor of more than two upon storage of the wafer at room temperature for a period of 5 months.