Hydrogen-atom number in platinum-hydrogen complexes in silicon

Four different platinum-hydrogen complexes are identified in silicon by transient capacitance spectroscopy. From deep-level depth profiling, we are able to identify the number of hydrogen atoms in the defect complexes. Three of the platinum-hydrogen complexes are electrically active, and contain one, two, and three hydrogen atoms, respectively. A complete electrical passivation of substitutional Pt is achieved by at least four hydrogen atoms. Our results are in agreement with experimental data on a $\mathrm{Pt}-{\mathrm{H}}_2$ complex and a theoretical study on the structure and level positions of these defect complexes.