High-energy (MeV) ion implantation is now being rapidly introduced into integrated circuit manufacturing because it promises process simplification and improved device performance. However, high-energy implantation introduces an imbalance of excess vacancies and vacancy-cluster defects in the near-surface region of a silicon crystal. These defects interact with dopants affecting diffusion and electrical activation during subsequent processing. The objective of this project was to develop sufficient understanding of the physical mechanisms underlying the evolution of these defects and interactions with dopant atoms to enable accurate prediction and control of dopant diffusion and defect configurations during processing. This project supported the DOE mission in science and technology by extending ongoing Basic Energy Sciences programs in ion-solid physics and x-ray scattering at ORNL into new areas. It also strengthened the national capability for advanced processing of electronic materials, an enabling technology for DOE programs in energy conversion, use, and defense.