Patent ID: 6416836
Filing Date: 2002-07-09
Classification: C30B,H01L,Y10T

Abstract:
A single crystal silicon wafer having a central axis, a front side and a back side which are generally perpendicular to the central axis, a central plane between the front and back sides, a circumferential edge, and a radius extending from the central axis to the circumferential edge, the wafer comprising:a first axially symmetric region, extending radially inwardly from the circumferential edge, in which silicon self-interstitials are the predominant intrinsic point defect and which is substantially free of agglomerated interstitial defects; and, a second axially symmetric region in which vacancies are the predominant intrinsic point defect, the second axially symmetric region comprising a surface layer extending from the front side toward the central plane and a bulk layer extending from the surface layer to the central plane, the number density of agglomerated vacancy defects present in the surface layer being less than the concentration in the bulk layer.