Deep-level transient spectroscopy of Pd-H complexes in silicon

Abstract

The interaction of atomic hydrogen with substitutional palladium impurities is studied in $n\ensuremath{-}$ and p-type Si by deep-level transient spectroscopy. After wet-chemical etching, we determine seven different electrically active and at least one passive palladium hydrogen complex. The levels belong to Pd complexes with different number of hydrogen atoms. The ${\mathrm{PdH}}_{1}$ complex exhibits one level $E(200)$ at ${E}_{C}\ensuremath{-}0.43 \mathrm{eV}.$ ${\mathrm{PdH}}_{2}$ has two levels $E(60)$ at ${E}_{C}\ensuremath{-}0.10 \mathrm{eV}$ and H(280) at ${E}_{V}+0.55 \mathrm{eV}.$ Four levels are assigned to the ${\mathrm{PdH}}_{3}$ complex $E(160)$ at ${E}_{C}\ensuremath{-}0.29 \mathrm{eV},$ H(140) at ${E}_{V}+0.23 \mathrm{eV},$ H(55) at ${E}_{V}+0.08 \mathrm{eV},$ and H(45) at ${E}_{V}+0.07 \mathrm{eV}.$ An electrically passive complex is associated with a ${\mathrm{PdH}}_{4}$ complex. There is great similarity with the correspondent complexes in Pt-doped Si. Annealing above 650 K destroys all hydrogen related complexes and restores the original substitutional Pd concentration.