End of range (EOR) secondary defect engineering using chemical vapor deposition (CVD) substitutional carbon doping
View Patent ↗A method for incorporating carbon into a wafer at the interstitial a-c silicon interface of the halo doping profile is achieved. A bulk silicon substrate is provided. A carbon-doped silicon layer is deposited on the bulk silicon substrate. An epitaxial silicon layer is grown overlying the carbon-doped silicon layer to provide a starting wafer for the integrated circuit device fabrication. An integrated circuit device is fabricated on the starting wafer by the following steps. A gate electrode is formed on the starting wafer. LDD and source and drain regions are implanted in the starting wafer adjacent to the gate electrode. Indium is implanted to form halo implants adjacent to the LDD regions and underlying the gate electrode wherein the halo implants extend to an interface between the epitaxial silicon layer and the carbon-doped silicon layer wherein carbon ions in the carbon-doped silicon layer act as a silicon interstitial sink for silicon interstitials formed by the halo implants to prevent end of range secondary defect formation.
1. 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.
2. The device according to claim 1 wherein said carbon-doped silicon layer is deposited by reduced pressure chemical vapor deposition.
3. The device according to claim 1 wherein said carbon-doped silicon layer has a thickness of between about 100 and 700 Angstroms.
4. The device according to claim 1 wherein said carbon-doped silicon layer has a carbon content of up to 0.5%.
5. The device according to claim 1 wherein said epitaxial silicon layer has a thickness of between about 300 and 500 Angstroms.
6. The device according to claim 1 wherein said heavy ions comprise antimony or indium.