Electrical measurements of annealed boron implants for shallow junctions

Ultra-low energy, 0.5-keV, boron implants were annealed at ramp-up rates of 150 degrees C/s in an incandescent-lamp system, or up to approximate to 1500 degrees C/s in an are-lamp system, to promote activation and minimize diffusion. Annealing treatments covered a range of temperatures and included "spike anneal" methods, which result in effective annealing times of approximate to 1 s for incandescent-lamps and approximate to 0.3 s for an are-lamp. Results for the electrical activation and junction depths were derived from measurements of sheet Hall van der Pauw electrical transport and from secondary ion mass spectroscopy. Isothermal annealing shows the dopant diffusion to have a square-root dependence on the effective annealing time for short annealing cycles. Accordingly, are-lamp annealing leads to a shallower junction than incandescent-lamp annealing. Similar relationships between sheet resistance and junction depth are observed for the two annealing methods.