Activation of Implanted Boron Atoms in Silicon Wafers by Infrared Semiconductor Laser Annealing Using Carbon Films as Optical Absorption Layers

摘要

We report continuous wave (CW) IR semiconductor laser annealing for the activation of boron atoms implanted into an n-type Si wafer with diamond-like carbon (DLC) films as optical absorption layers. Boron atoms were implanted at l0keV at doses of 5 x 10~(14), 1 × 10~(15), and 1.5 × 10~(15)cm~(-2). The depth at the boron concentration of 10~(18)cm~(-2) was 50nm. Samples were annealed by irradiation at 66.5 - 80.5 kW/cm~2 and 2.6 ms. The sheet resistance of the sample markedly decreased to 531 Ω/sq for implantation at 1.5 × 10~(15) cm~(-2) by laser annealing. Boron atoms were almost completely activated at a carrier density near the boron concentration for implantation at l0keV. The largest diffusion length of boron atoms was 3 nm.