Atomic layer deposition and characterization of stoichiometric erbium oxide thin dielectrics on Si(1 0 0) using (CpMe)3Er precursor and ozone

Thin stoichiometric erbium oxide films were atomic layer deposited on p-type Si(100) substrates using tris(methylcyclopentadienyl)erbium and ozone. The film growth rate was found to be 0.12 ± 0.01 nm/cycle with an atomic layer deposition temperature window of 170-330 ºC. X-ray photoelectron spectral (XPS) analysis of the resulting Er2O3 films indicated the as-deposited films to be stoichiometric with no evidence of carbon contamination. Studies of post deposition annealing effects on resulting films and interfaces were done using Fourier transforms infrared spectroscopy, XPS, glancing incidence X-ray diffraction, and optical surface profilometry. As-deposited Er2O3 films were found to crystallize in the cubic structure with dominant (222) orientation; no erbium silicate was found at the interface. After annealing at 800 ºC in N2 for 5 min, a new XPS feature was found and it was assigned to the formation of erbium silicate. As the annealing temperature was increased, the interfacial erbium silicate content was found to increase in the temperature range studied.