| Ion implantation is used to introduce dopant atoms into the silicon lattice during the processing of integrated circuits. For deep sub-micron transistors the electrical junction formed by the implanted dopant is constrained by maximum levels of sheet resistance, junction depth and junction leakage current. Ion implantation inherently produces large concentrations of excess silicon interstitials. These interstitials mitigate three processes: dopant activation, dopant diffusion, and extended defect formation, which directly affect the aforementioned junction characteristics. This work is the culmination of two consecutive projects centering on ion implantation of dopants in silicon. The first project was to investigate the fundamental processes associated with amorphizing ion implantation, particularly the correlation between extended defect evolution and dopant diffusion. The second project was more applied, seeking to determine if it was possible to introduce an impurity into silicon, co-implanted with boron, that would decrease boron diffusion. The result of this work is a greater understanding of boron diffusion in the presence of fluorine, an element that is pervasive in integrated circuit manufacturing. |
