Anisotropy Of The Thermal Expansion Of The Ni(Si1-Xgex) Phases Investigated By High-Temperature X-Ray Diffraction

Thin films of Ni(Si1-xGex) are of interest for their applications in metal-oxide semiconductor transistors as contacts and interconnections. In this work, the lattice parameters and the coefficients of linear thermal expansion (gamma(a), gamma(b), and gamma(c)) of the orthorhombic Ni(Si1-xGex) alloys, with 0 <= x <= 1, were determined from high-temperature x-ray diffraction data (298-1073 K). A negative thermal expansion along the b axis of Ni(Si1-xGex) is observed for all x values of the Ge concentration: the magnitude of the thermal expansion coefficient decreases with increasing Ge concentration. The anisotropy of the thermal expansion is potentially important for the integration of Ni(Si1-xGex) in microelectronic devices. (c) 2007 American Institute of Physics.