Annealing behavior of light scattering tomography defect in the denuded zone of Si wafers

Light scattering tomography defects (LSTDs) have been non-destructively det ected in bulk and near the surface of a Si wafer by Brewster angle illumina tion of infrared light scattering tomography (IR-LST). We investigated the annealing behavior of grown-in LSTDs that exist in a layer of 0 to about 20 mu m depth from the wafer surface. Grown-in LSTDs were detected before ann ealing. Annealing behavior of such grown-in LSTDs was studied by the three- step annealing to form the denuded zone (DZ) of about 40 mu m. As a result, the LSTDs mostly remained in the DZ after the three-step annealing. Howeve r, the change in the scattering intensity of the grown-in LSTDs was detecte d. This change suggests that the volume and/or structure was changed by the annealing treatment.