Electrical Properties of Bulk Grown Nitrogen Doped Silicon

摘要

The electrical parameters of a boule of nitrogen doped float zone silicon were studied by Hall effect analysis. Samples were annealed at temperatures ranging from 800 to 900 C. In addition, a section of this boule was neutron transmutated (NTD) to increase the n-type doping. Samples from the NTD section were annealed at 800 C. Resistivity and mobility varied considerably from sample to sample, but the variation is not a function of annealing temperature. The annealed Si:N samples were found to be inhomogeneous; however, the Si:N NTD samples were homogeneous. In addition, annealing activated deep energy levels. The shallow energy levels reported in studies on ion implanted nitrogen in silicon were not found. The only shallow energy level found was phosphorus. The conclusion is nitrogen does not go into substitutional sites in silicon to any great extent. Although what happens to nitrogen in silicon is unknown it is suggested that nitrogen may form silicon-nitride complexes and precipitates, This could be the mechanism for strengthening the lattice.