Method for laser cleaning of a substrate surface using a solid sacrificial film

Abstract

An improved semiconductor wafer processing apparatusincludes a series of processing stations combined in one form, coupled together by computer-controlled cluster tooling. Wafers are supplied in a pod to an input stationwhich initiates a data record for recording processing results at each station. A sacrificial filmis applied to the surfaceof each wafer. Individual wafers are transferred to a computer-controlled defect-mapping stationwhere particulate defectsare identified and their position coordinates recorded. Defect-mapped wafers are transferred to a computer-controlled laser area cleaning stationwhich lifts the defects and sweeps the wafer surface clean, except for stubborn defects. Clean wafers are transferred to a final mapping stationor, followed by transfer of the wafers to an output station. Wafers having remaining stubborn defects are transferred to a second defect-mapping stationwhere stubborn defects are located by coordinates, after which the wafers are transferred to a defect review tool incorporating a scanning electron microscope (SEM-DRT). A SEM image review of stubborn defects includes chemical analysis of the stubborn defects. A laser point-cleaning stationlifts and sweeps each stubborn defect individually from the wafer surface. Cleaned wafers are transferred to a third defect-mapping stationfor recording any stubborn defects remaining, then to a second laser area cleaning stationfor a final cleaning, followed by transfer of the wafers to a final mapping stationorfor mapping of any remaining stubborn defects. The accompanying data records are updated followed by transfer of the wafers to an output station