Nickel-platinum alloy monosilicidation-induced defects in n-type silicon

Abstract

Electrically active defects induced by the formation of nickel–platinum alloy monosilicide (formed at 600–800 °C) has been studied in n-type silicon using deep level transient spectroscopy and transmission electron microscopy measurements. A Ni-related electron trap level at Ec−0.42 eV is observed after silicidation at 600 °C or above and a Pt-related electron trap level at Ec−0.50 eV is detected after silicidation at 700 °C or above. Two hole trap levels at Ev+0.22 and Ev+0.28 eV are also detected, Ev+0.22 eV level for silicidation at 700 °C or above and Ev+0.28 eV level for 600 °C silicidation. For the sample silicided at 600 °C, an additional electron trap level (located at Ec − 0.16 eV) with a broad spectral peak is detected in the near-surface region (<0.65 μm) of the sample in which some {311} type defects of 50–100 Å long are also observed. Most of observed electrically active defects have been found to be present in near-surface regions (<2 μm). Lowest total defect concentration is observed in the sample silicided at 700 °C where lowest reverse saturation current is also observed, indicating that the Ni(Pt) monosilicidation-induced electrically active defects are effective recombination/generation centers.