Interface stability of Ti(SiGe){sub 2} and SiGe alloys: Tie lines in the ternary equilibrium diagram

Journal Article · Sat Jun 01 04:00:00 EDT 1996 · Physical Review, B: Condensed Matter

DOI:https://doi.org/10.1103/PhysRevB.53.16279· OSTI ID:285604

Aldrich, D B ^[1]; dHeurle, F M ^[2]; Sayers, D E; Nemanich, R J ^[1]

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1. Department of Physics, North Carolina State University, Raleigh, North Carolina 27695-8202 (United States)
2. IBM Thomas J. Watson Research Center, Yorktown Heights, New York 10598 (United States)

The C54 phases of TiSi{sub 2} and TiGe{sub 2} are known to be completely miscible, however, we have observed that thin films of C54 Ti(Si{sub 1{minus}{ital y}}Ge{sub {ital y}}){sub 2} are not stable in contact with Si{sub 1{minus}{ital x}}Ge{sub {ital x}} when {ital y}={ital x}. In this study it is shown that this interface instability can be related to the composition-dependent energetics that determine the Ti-Si-Ge ternary equilibrium diagram. Tie lines of the Ti(Si{sub 1{minus}{ital y}}Ge{sub {ital y}}){sub 2} to Si{sub 1{minus}{ital x}}Ge{sub {ital x}} system were calculated on the basis of classical thermodynamics. The calculations indicate that for C54 Ti(Si{sub 1{minus}{ital y}}Ge{sub {ital y}}){sub 2} to be stable in contact with Si{sub 1{minus}{ital x}}Ge{sub {ital x}} the compositions of the two phases must be such that {ital y}{lt}{ital x}. The specific compositions of the two phases in equilibrium depend on the temperature and the relative quantities of the two phases. The dynamics of the interface reactions of C54 Ti(Si{sub 1{minus}{ital y}}Ge{sub {ital y}}){sub 2} on Si{sub 1{minus}{ital x}}Ge{sub {ital x}} are related to the calculated tie lines, and the diffusion kinetics of the materials. Experimental results are presented that quantitatively support the model calculations. {copyright} {ital 1996 The American Physical Society.}

• DOE Contract Number: FG05-89ER45384
• OSTI ID: 285604
• Journal Information: Physical Review, B: Condensed Matter, Journal Name: Physical Review, B: Condensed Matter Journal Issue: 24 Vol. 53; ISSN 0163-1829; ISSN PRBMDO
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
DIFFUSION
GERMANIUM ALLOYS
INTERFACES
METAL-SEMICONDUCTOR CONTACTS
PHASE DIAGRAMS
SEGREGATION
SILICON ALLOYS
THERMODYNAMIC PROPERTIES
TITANIUM
TITANIUM ALLOYS