Auger Analysis Across an Interface Between Cr Film and Pure Silica(Physics, Process, Instrument & Measurements)
The valence Auger spectra across the interface between Cr film and pure SiO_2 glass (Cr/SiO_2) are measured after annealing and compared with that of Cr film on a Si wafer (Cr/Si) for the purpose of understanding the chemical bonding across the interface between metals (films) and ceramics (substrates). It is observed in the interface of Cr/SiO_2 after annealing that oxygen and chromium more preferentially diffuse than Si. It is found from the Auger-intensity-ratio that a Cr-Si bond is formed at the interface as a result of the diffusion of Cr into SiO_2-substrate, although no silicide layers are observed. This Cr-Si bond is much more metallic than an Si-O bond according to the difference in the kinetic energy of Auger electrons. On the other hand, oxygen takes electrons from the 3d state of Cr atom by diffusing into the Crfilm. A Cr-O bond is consequently formed in the metal side of the interface. It is suggested that the monotonical change in electronic structure is achieved across the interface of Cr/SiO_2. Both Cr-O bonds and Cr-Si bonds are formed as a result of the monotonical change in the electronic structure.
- Transactions of JWRI
Transactions of JWRI 23 (1), 27-34, 1994-06