Recrystallization Behavior of Silicon Implanted with Phosphorus Atoms by Infrared Semiconductor Laser Annealing

Abstract

We report the recrystallization behavior of silicon implanted with phosphorus atoms at 10 and 70 keV with a dose of 2×1015 cm-2. The samples were coated with a 200-nm-thick diamond-like-carbon optical absorption layer and then annealed by irradiation with a 940 nm continuous-wave laser at 70 kW/cm2. An analysis of optical reflectivity spectra showed an in-depth distribution of the crystalline volume ratio. The amorphized surface regions produced by the phosphorus implantation were recrystallized from the bottom region by laser annealing. They were almost completely recrystallized by the laser annealing for 2.6 ms. The in-depth profiles of phosphorus concentration hardly changed for the laser annealing for 2.6 ms. The implanted regions were effectively activated by the laser annealing and the sheet resistance markedly decreased to 102 and 46 Ω/sq for implantion at 10 and 70 keV, respectively.