Application of Wright Etch in failure analysis on localized abnormal implant profile in wafer fabrication

In this paper, four low yield cases related to implantation issues in semiconductor wafer fabrication process on Si CMOS device were presented. Wright Etch method was shown to be effective in localizing non-uniform implantation and detecting abnormal implant profile in the Si active area. The etch depth profile and surface morphology after Wright Etch were used primarily to determine any abnormality in the implantation. This method has been demonstrated useful for top view planar inspection using scanning electron microscope (SEM).