Patent ID: 8309464
Filing Date: 2012-11-13
Classification: H01L,Y10T

Abstract:
1. A method for removing silicon from a surface of a silicon wafer, the wafer comprising a central axis, a front surface and a back surface that are generally perpendicular to the central axis, a peripheral edge, a radius, R, extending from the central axis to a point along the peripheral edge of the wafer, a nearest peripheral edge point along the peripheral edge of the wafer nearest the central axis, and edge portions of the front and back surfaces of the wafer that extend from the nearest peripheral edge point to a point between the nearest peripheral edge point and the central axis and no more than about 15 mm from the nearest peripheral edge point, the method comprising: immersing and contacting with an etchant only (i) the peripheral edge of the wafer, (ii) the edge portion of the front surface of the wafer, and (iii) the edge portion of the back surface of the wafer, thereby producing an edge-etched wafer; and reducing the flatness of the front surface of the edge-etched wafer by more than about 50% by lapping or grinding.