Reverse annealing of boron in boron implanted silicon

This dissertation describes a study intended to clarify, in boron-implanted silicon, the mechanism of boron reverse annealing which occurs in the temperature range from 550 to about 7000C. The electrical properties of a boron implanted silicon were correlated with cross-sectional Transmission Electron Microscopic (XTEM) studies and Deep Level Capacitance Transient Spectroscopic (DLTS) studies. Isothermal kinetic studies were performed to characterize the evolution and diminution of boron reverse annealing. Rapid thermal annealing (RTA) using tungsten-halogen lamps was employed for the study of the early time kinetics of reverse annealing. Float Zone (FZ) silicon wafers were used to investigate the effect of oxygen on reverse annealing. Boron and argon implants into p- silicon wafers were carried out to sort out the defect species responsible for reverse annealing. The role of rod-like defects, which are commonly observed in an annealed boron implanted silicon, was also examined. Results point to boron-vacancy complex model as the most appropriate mechanism for boron reverse annealing. It is shown that precipitation, rod-like defects, and the Watkins' displacement mechanism are unlikely as causes for reverse annealing. Reverse annealing is a reaction that has a limited supply of reactants as revealed by the kinetic study