LATERAL STRAGGLING OF B AND P IONS IMPLANTED IN CHANNELING AND RANDOM DIRECTIONS OF SI SINGLE-CRYSTALS

Boron and phosphorus ions at energies of 400 keV and 1 MeV were implanted along the [100] axis or in a random direction of silicon wafers covered by a sequence of 10-mu-m wide and 3-mu-m thick SiO2 stripes. Two-dimensional isoconcentration contour lines at the substrate doping level were determined by a new technique based on spreading resistance profiling. The lateral distribution under the mask of ions implanted in a random direction is always broader than that of ions implanted along the [100] axis. With increasing the dose of the channeled implants the lateral penetration also increases due to the scattering of channeled ions by the silicon atoms displaced from lattice sites