Surface compositions of copper-silicon alloys

Reaction of nanometer-sized Cu particles with a SiO2 substrate

“…Strongly bonded Cu may catalyze the Si-O bond breaking, since Cu also catalyzes the reverse reactions of Si-O formation. 13,14,[16][17][18] Metal evaporation as applied by others 9,21 may result in a weaker metal-support interaction 4 and, therefore, not result in a reaction between Cu and SiO 2 during UHV annealing. We note that also impurities on the sample surface or constituents of the residual gas may help to reduce SiO 2 .…”

“…13,14,16 Roomtemperature oxidation of Si is catalyzed by Cu 3 Si and a thick amorphous SiO 2 layer grows spontaneously beneath the Curich layer. 17,18 So the ease of regeneration of the annealed Cu/SiO 2 samples as described above can be understood from the oxidation behavior of a silicide and is another piece of evidence for the presence of Cu silicide after annealing in UHV.…”

“…Cu silicide can be distinguished by the splitting of the Si LVV peak at 92 eV into two peaks at 90 and 94 eV. 13,14 In Fig. 2, AES spectra of the Si LVV region of our Cu/SiO 2 system are presented after various treatments.…”

“…These results are in good agreement with AES measurements on bulk Cu silicides by Frank and Falconer. 13 AES measurements were repeated during UHV annealing of a SiO 2 substrate without Cu particles. Only a weak signal at 92 eV could be discerned, which may be attributed to a small amount of Si formed by the reduction of SiO 2 by the electron beam.…”

Fabrication and characterization of CuxSi1−x films on Si (111) and Si (100) by pulsed laser deposition

“…There were two or more possible Cu nucleation on Si surface, resulting compositions were highly complex, 19 and the researchers suggested there was a high reaction activity between copper and silicon. [20][21][22][23] In this current study, we try to control the stoichiometry and microstructure of Cu x Si 1−x films on Si (001) and (111) by PLD technique. The influences of laser energy fluency, deposition temperature, substrate orientation, and heat treatments on orientations and structures, surface morphologies were investigated.…”