Film thickness effects in the Ti--Si{sub 1{minus}{ital x}}Ge{sub {ital x}} solid phase reaction
- Department of Physics, North Carolina State University, Raleigh, North Carolina 27695-8202 (United States)
The effects of film thickness on the Ti--Si{sub 1{minus}{ital x}}Ge{sub {ital x}} solid phase reaction were investigated. Thin C49 TiM{sub 2} (M=Si{sub 1{minus}{ital y}}Ge{sub {ital y}}) films were formed from the solid phase reaction of 400 A Ti or 100 A Ti with Si{sub 1{minus}{ital x}}Ge{sub {ital x}} alloys. It was determined that for films formed from 400 A Ti, the nucleation barrier of the C49-to-C54 transformation decreases with increasing germanium content, for alloy compositions with up to {approx}40 at. % germanium (i.e., {ital x}{le}0.40). It was also observed that germanium segregates out of the TiM{sub 2} lattice, for both the C49 and C54 phases, and is replaced on the TiM{sub 2} lattice with Si from the substrate. The germanium segregation changes the Ge index {ital y} of the Ti(Si{sub 1{minus}{ital y}}Ge{sub {ital y}}){sub 2}. For films formed from a 100 A Ti layer it was observed that the C54 TiSi{sub 2} nucleation temperature was increased by {ge}125 {degree}C. The addition of germanium to the silicon increased the agglomeration of the C49 phase and caused the C54 TiM{sub 2} nucleation barrier to increase further. The results also indicate that the increased temperature required for the transition to the C54 phase, for the 100 A films, leads to an increased rate of germanium segregation. {copyright} {ital 1995} {ital American} {ital Institute} {ital of} {ital Physics}.
- DOE Contract Number:
- FG05-89ER45384
- OSTI ID:
- 253338
- Journal Information:
- Journal of Applied Physics, Journal Name: Journal of Applied Physics Journal Issue: 8 Vol. 78; ISSN JAPIAU; ISSN 0021-8979
- Country of Publication:
- United States
- Language:
- English
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