Abstract
A copper-aluminium (CuAl) alloy (90%:10% wt) has been investigated in relation to segregation of the alloying element Al, from the alloy bulk during vacuum anneal treatments. X-ray photoelectron spectroscopy (XPS) measurements were used to track the surface enrichment of Al segregating from the alloy bulk during in situ ultra-high vacuum anneals. Secondary ion mass spectroscopy (SIMS) indicates a build-up of Al at the surface of the annealed alloy relative to the bulk composition. Metal oxide semiconductor (MOS) CuAl/SiO2/Si structures show a shift in flatband voltage upon thermal anneal consistent with the segregation of the Al to the alloy/SiO2 interface. Electrical four point probe measurements indicate that the segregation of Al from the alloy bulk following thermal annealing results in a decrease in film resistivity. X-ray diffraction data shows evidence for significant changes in crystal structure upon annealing, providing further evidence for expulsion of Al from the alloy bulk.
| Original language | English |
|---|---|
| Pages (from-to) | 59-63 |
| Number of pages | 5 |
| Journal | Thin Solid Films |
| Volume | 599 |
| DOIs | |
| Publication status | Published - 29 Jan 2016 |
| Externally published | Yes |
Keywords
- Aluminium
- Copper
- CuAl alloy
- Self-forming barrier
- XPS
- XRD