Structure of hydrogen center in D-implanted Si

Ion-implantation and ion-channeling measurements have been used to study deuterium (D) in silicon. The D was introduced at room temperature by implantation to 13 keV into single-crystal Si. The D was detected and its depth profile was measured by the $\mathrm{D}({}_{}{}^3{}_{}{}^{}\mathrm{He}, p){}_{}{}^4{}_{}{}^{}\mathrm{He}$ nuclear reaction, and simultaneously the Si lattice signal was obtained from the ${}_{}{}^3{}_{}{}^{}\mathrm{He}$ backscattering. Comparisons of the observed channeling angular distributions with continuum-model calculated distributions for the $〈111〉$, $〈110〉$, and $〈100〉$ axial and {110} planar channeling directions indicate that the D is located predominantly in a single interstitial site 1.6 A along a $〈111〉$ direction from a Si atom in the antibonding direction. The resulting structure is compared to other known impurity interstitial centers in Si and implications of this site are discussed.