Formation of Shallow PN Junction by Cluster Boron Implantation and Rapid Annealing Using Infrared Semiconductor Laser

Abstract

We report shallow PN junctions and analysis of their electrical characteristics. Infrared semiconductor laser annealing using carbon films as optical absorption layer was adapted to the activation of silicon implanted with boron cluster ions. We carried out implantations of boron clusters at 6 keV with an equivalent boron concentration of 1.0×1015 cm−2. Laser irradiation at 375 kW/cm2 was conducted to activate impurities. Secondary ion mass spectroscopy revealed that boron atoms with a concentration of 6.0×1014 cm−2 were incorporated into silicon surface within a 10 nm depth. The free carrier absorption analyses and current‐voltage characteristics of the PN junction diode indicated that the boron atoms were effectively activated by laser annealing.