Patent ID: 7097718
Filing Date: 2006-08-29
Classification: C30B,Y10T

Abstract:
1. An epitaxial silicon wafer comprising: a single crystal silicon substrate comprising agglomerated vacancy defects and having a central axis, a front surface and a back surface which are generally perpendicular to the central axis, a circumferential edge, and a radius extending from the central axis to the circumferential edge, the substrate comprising a first axially symmetric region in which silicon self-interstitials are the predominant intrinsic point defect and which is substantially free of agglomerated interstitial defects, the axially symmetric region extending radially inwardly from the circumferential edge of the substrate and having a radial width of at least about 40% of the length of the radius of the substrate; an epitaxial layer deposited upon a surface of the substrate, the epitaxial layer being substantially free of grown-in defects, wherein the epitaxial layer has a thickness of about 1 to about 15 microns.