Au and Al interface reactions with SiO2

Abstract

The chemical bonding, extent, and evolution of metal‐oxide semiconductor interface regions have been probed with soft‐x‐ray photoemission spectroscopy following room‐temperature, in situ metallization. We identify strong atomic rearrangement and charge transfer at metal‐SiO₂ interfaces. The quantitatively different processes found for Au and Al suggest new structural models. For Al‐SiO₂, Al first clusters about each surface O and then grows Al₂O₃ by reducing SiO_x (X < 2) and leaving excess Si at the interface. In contrast, Au forms islands on SiO₂ with evidence of Au–Si bonding, causing an SiO_x layer beneath the contact.