Interfacial deep levels responsible for schottky barrier formation at semiconductor/metal contacts Academic Article uri icon

abstract

  • The following facts, and many others, concerning III-V (e.g., GaAs, InP) Schottly barriers can be understood in terms of Fermi-level pinning by interfacial antisite defects (sheltered by vacancies) at semiconductor/metal contacts: (i) the barrier heights are almost independent of the metal in the contact; (ii) the surface Fermi levels can be pinned at sub-monolayer coverages and the pinning energies are almost unaffected by changes of stoichiometry or crystal structure; (iii) the schottky barrier heigh for n-InP with Cu, Ag, or Au is {reversed tilde equals}0.5 eV, but changes to {reversed tilde equals}0.1 eV when reactive metal contacts (Fe, Ni, or Al) are employed because the antisite defects are dominated by P vacancies; and (iv) the dependence on alloy composition or alloys of AlAs, GaAs, GaP, InAs, and GaAs is extremely complex - owing to the dependence of the binding energy for the cation-on-anion-site deep level on alloy composition. Fermi-level pinning by Si dangling bonds at Si/transition-metal silicide interfaces accounts for the following facts: (i) the barrier heights are independent of the transition-metal, to within {reversed tilde equals}0.3 eV; (ii) on the 0.1 eV scale there are chemical trends in barrier heights for n-Si, with the heights decreasing in the order Pt, Pd, and Ni; (iii) barriers form at low metallic coverage, (iv) barrier heights are independent of silicide crystal structure or stoichiometry to ± 0.1 eV; and (v) the barrier heights for n-Si and p-Si add up to approximately the energy of the band gap. © 1985.

author list (cited authors)

  • Dow, J. D., Sankey, O. F., & Allen, R. E.

citation count

  • 7

publication date

  • January 1985