Effects of molecular versus atomic oxygen on NiSi and Ni(Pt)Si films grown on both p- and n-doped Si(100)

Abstract

Effects of mixed atomic/molecular oxygen (O+O2) and pure O2 on the surface compositions of Ni(Pt)Si (on n-doped substrates) and NiSi films on p- or n-doped Si(100) substrates have been characterized by x-ray photoemission spectroscopy. Exposure to O+O2 results in rapid silicon consumption and the kinetically driven oxidation of the transition metal(s), with oxides >35Å thick formed on all samples without passivation. The addition of Pt retards but does not eliminate oxide growth or Ni oxidation. Substrate dopant type has no effect on oxidation rate except at high exposures where there is a slight enhancement of n-type oxidation. Exposure to O2 yields rapid passivation after the formation of a SiO2 film 6–7Å thick on all samples.