Activation of Silicon Implanted with Phosphorus and Boron Atoms by Infrared Semiconductor Laser Rapid Annealing

We report the activation of silicon implanted with phosphorus and boron atoms by infrared semiconductor laser annealing using carbon films as an optical absorption layer. 2-mu m surface region was heated above 1000 degrees C longer than 22 mu s by scanning the laser beam for a dwell time of 40 mu s. We carried out implantations of 1 x 10(15) cm(-2) phosphorus atoms at 100, 300, and 500 keV, and boron clusters with a boron concentration of 1 x 10(15) cm(-2) at 6 keV. Laser irradiation at 375 kW/cm(2) was conducted to activate impurities. Secondary ion mass spectrometry measurement revealed that laser annealing caused no substantial change in the phosphorus and boron atom profiles. Laser-induced recrystallization of surface amorphized regions caused by the ion implantation was analyzed using the optical reflectivity spectra ranging from 250 to 1000 nm. The free carrier absorption analyses indicated that the phosphorus and boron atoms were effectively activated by laser annealing. (C) 2010 The Japan Society of Applied Physics