Patent ID: 7400018

Claim:
An integrated circuit device comprising: a bulk silicon substrate; a carbon-doped silicon layer overlying said bulk silicon substrate; and an epitaxial silicon layer overlying said carbon-doped silicon layer; a gate electrode on said bulk silicon substrate; LDD regions within said epitaxial silicon layer adjacent to said gate electrode; source and drain regions within said epitaxial silicon layer adjacent to said gate electrode and extending through said carbon-doped silicon layer into said bulk silicon substrate; and heavy ion implants adjacent to said LDD regions and underlying said gate electrode wherein said heavy ion implants extend downward through said epitaxial silicon layer to an interface between said epitaxial silicon layer and said carbon-doped silicon layer wherein carbon ions in said carbon-doped silicon layer act as a silicon interstitial sink for silicon interstitials formed by said halo implants to prevent end of range secondary defect formation.