Low-energy carbon and nitrogen ion implantation in silicon

Silicon wafers have been implanted with C+, N+, and C++N+ ions at low energ ies to form buried insulating layers. Buried silicon nitride layers with Si or SiC small crystalline clusters were segregated after annealing at high temperature, leaving a high-crystalline-quality overlayer on top. In the sa mples implanted with C+ alone, after annealing, the silicon overlayer exhib its a lattice contraction of about 0.04%. In the N+-implanted samples this contraction is between 0.08% and 0.13%. The C++N+ implantation leads to rel axation of the lattice after annealing, with no reduction of the lattice co nstant. (C) 2001 American Vacuum Society.