A method for inspecting a substrate for defects, including: A method for inspecting a substrate for defects, the method including the steps of: (i) obtaining at least two wafer element detection signal; each wafer element detection signal reflects light scattered to a distinct direction; each wafer element detection signal having a wafer element detection value; (ii) calculating at least one wafer element attribute value in response to the at least two wafer element detection signals; retrieving at least one reference wafer element attribute value, each wafer element attribute value corresponding to a reference wafer element attribute value; and (iii) determining a relationship between the at least one reference wafer element attribute value, wafer element attribute value and at least one threshold to indicate a presence of a defect.