Electrical and structural properties of zirconium germanosilicide formed by a bilayer solid state reaction of Zr with strained Si{sub 1{minus}x}Ge{sub x} alloys
- Department of Physics, North Carolina State University, Raleigh, North Carolina 27695-8202 (United States)
The effects of alloy composition on the electrical and structural properties of zirconium germanosilicide (Zr{endash}Si{endash}Ge) films formed during the Zr/Si{sub 1{minus}x}Ge{sub x} solid state reaction were investigated. Thin films of Zr(Si{sub 1{minus}y}Ge{sub y}) and C49 Zr(Si{sub 1{minus}y}Ge{sub y}){sub 2} were formed from the solid phase reaction of Zr and Si{sub 1{minus}x}Ge{sub x} bilayer structures. The thicknesses of the Zr and Si{sub 1{minus}x}Ge{sub x} layers were 100 and 500 {Angstrom}, respectively. It was observed that Zr reacts uniformly with the Si{sub 1{minus}x}Ge{sub x} alloy and that C49 Zr(Si{sub 1{minus}y}Ge{sub y}){sub 2} with y=x is the final phase of the Zr/Si{sub 1{minus}x}Ge{sub x} solid phase reaction for all compositions examined. The sheet resistance of the Zr(Si{sub 1{minus}y}Ge{sub y}){sub 2} thin films was higher than the sheet resistance of similarly prepared ZrSi{sub 2} films. The stability of Zr(Si{sub 1{minus}y}Ge{sub y}){sub 2} in contact with Si{sub 1{minus}x}Ge{sub x} was investigated and compared to the stability of Ti(Si{sub 1{minus}y}Ge{sub y}){sub 2} in contact with Si{sub 1{minus}x}Ge{sub x}. The Ti(Si{sub 1{minus}y}Ge{sub y}){sub 2}/Si{sub 1{minus}x}Ge{sub x} structure is unstable when annealed for 10 min at 700{degree}C, with Ge segregating from Ti(Si{sub 1{minus}y}Ge{sub y}){sub 2} and forming Ge-rich Si{sub 1{minus}z}Ge{sub z} precipitates at grain boundaries. In contrast, no Ge segregation was detected in the Zr(Si{sub 1{minus}y}Ge{sub y}){sub 2}/Si{sub 1{minus}x}Ge{sub x} structures. We attribute the stability of the Zr-based structure to a smaller thermodynamic driving force for germanium segregation and stronger atomic bonding in C49 Zr(Si{sub 1{minus}y}Ge{sub y}){sub 2}. Classical thermodynamics were used to calculate Zr(Si{sub 1{minus}y}Ge{sub y}){sub 2}{endash}Si{sub 1{minus}x}Ge{sub x} tie lines in the Zr{endash}Si{endash}Ge ternary phase diagram. (Abstract Truncated)
- Research Organization:
- Brookhaven National Laboratory
- DOE Contract Number:
- AC02-76CH00016; FG02-89ER45384
- OSTI ID:
- 664448
- Journal Information:
- Journal of Applied Physics, Journal Name: Journal of Applied Physics Journal Issue: 5 Vol. 82; ISSN JAPIAU; ISSN 0021-8979
- Country of Publication:
- United States
- Language:
- English
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