Reliability of shallow n(+)-type layers formed in dual As and B implanted silicon by rapid thermal annealing

Czochralski-grown 20 Omega cm, B-doped, (100) Si wafers were implanted with combinations of As+ and B+ ions at energies such that their respective projected ranges coincide at a position of about 30 nm, The implanted dose of As+ ions was 1 x 10(16) cm(-2) and those of B+ ions were in the range of 2.4 x 10(14) - 5 x 10(15) cm(-2). The samples were annealed at 950 degrees C for 10 s using halogen lamps. The junction was formed at a depth of about 120 nm for Si implanted with doses below 2.4 x 10(15) cm(-2) of B+ ions. The junction, however, could not be formed for Si implanted with a dose of 5 x 10(15) cm(-2) of B+ ions. The sample changed to n-type by subsequent furnace annealing at 950 degrees C for 30-300 min. The junction depth became shallower with dose of B+ ions because an inactive and immobile complex such as AsB is formed in the surface region.