Multiple halo implant in a MOSFET with raised source/drain structure

A method of making a MOSFET, comprising:

• providing a substrate having a gate oxide and gate formed thereon;
• implanting a shallow source/drain extension dopant in the substrate, thereby forming a source extension region and a drain extension region;
• forming a spacer on a sidewall of the gate a first time;
• forming raised source region and a raised drain region on the substrate;
• implanting a deep source/drain dopant in the substrate, thereby a deep source region and a deep drain region;
• annealing the substrate a first time;
• removing the spacer, thereby forming a void;
• implanting a deep halo dopant through the void and in the substrate, thereby forming a deep halo region;
• annealing the substrate a second time;
• implanting a shallow halo dopant in the substrate, thereby forming a shallow halo region;
• annealing the substrate a third time;
• forming a spacer on a sidewall of the gate a second time;
• forming a silicide on the gate and on the raised source/drain regions;
• and
• completing fabrication of the MOSFET,
• wherein the raised source/drain regions are formed by selective epitaxial growth,
• wherein the shallow source/drain extension dopant implanting step comprises implanting a dopant selected from a group consisting essentially of B+, BF2+, As+, Sb+, P+ to a depth range of approximately 10 nm to approximately 30 nm,
• wherein the deep halo implanting step and the shallow halo implanting step comprise implanting a dopant selected from a group consisting essentially of In+, Ga+, B+, BF2+, As+, Sb+, P+ at an angular range of approximately 0° to approximately 15°,
• wherein the first time annealing step is performed in a temperature range of approximately 1000° C. to approximately 1050° C.,
• wherein the second time annealing step is performed in a temperature range of approximately 900° C. to approximately 1000° C.,
• wherein the third time annealing step is performed in a temperature range of approximately 800° C. to approximately 900° C.,
• wherein the deep halo implanting step comprises implanting the dopant to a depth range of approximately 40 nm to approximately 100 nm,
• wherein the shallow halo implanting step comprises implanting the dopant to a depth range of approximately 10 nm to approximately 30 nm,
• wherein the shallow source/drain extension dopant implanting step comprises implanting the dopant in an energy range of approximately 0.5 KeV to approximately 5 KeV,
• wherein the deep source/drain dopant implanting step comprises implanting the dopant in an energy range of approximately 0.5 KeV to approximately 5 KeV,
• wherein the deep halo dopant implanting step comprises implanting the dopant in an energy range of approximately 5 KeV to approximately 60 KeV, and
• wherein the shallow halo dopant implanting step comprises implanting the dopant in an energy range of approximately 5 KeV to approximately 60 KeV.