Abstract
Cu-(27at.% Ti) and Cu-(26at.% Cr) alloys codeposited on silicon dioxide substrates were isochronally annealed for 30 min at 400-700 °C in a flowing NH3 ambient. In the Cu-Ti alloy, Ti segregates to the free surface to form a TiNx(O) layer and also to the alloy-SiO2 interface to form a Ti5 Si3 TiOw bilayer structure. Therefore the resulting structure is an almost completely dealloyed Cu layer located between a surface oxygen-rich Ti nitride and Ti-silicide/Ti-oxide bilayer interfacial structure. In the Cu-Cr alloy system, Cr seems to migrate only to the free surface to form a CrNx passivation layer. A 45 nm Al film was deposited after nitridation, whereupon a second anneal was performed to evaluate these nitride layers as diffusion barriers. The Cr-nitride diffusion barrier is stable up to 600 °C compared with Ti nitride that fails at 500 °C. The Cu-Cr nitrided samples also showed an overall lower sheet resistance.
Original language | English (US) |
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Pages (from-to) | 199-208 |
Number of pages | 10 |
Journal | Thin Solid Films |
Volume | 262 |
Issue number | 1-2 |
DOIs | |
State | Published - Jun 15 1995 |
Keywords
- Ammonia
- Diffusion
- Titanium nitride
- Titanium oxide
ASJC Scopus subject areas
- Electronic, Optical and Magnetic Materials
- Surfaces and Interfaces
- Surfaces, Coatings and Films
- Metals and Alloys
- Materials Chemistry