The formation of NiSi films from the reaction of Ni2Si with (100) and (111) silicon substrates was found to be controlled by a lattice diffusion process with an activation energy of 1.70 eV. In order to correlate kinetic information obtained by Rutherford backscattering with x-ray diffraction data, ‘‘standard’’ diffraction powder patterns for both Ni2Si and NiSi have been established. The existence of a metastable hexagonal form of NiSi has been confirmed. Observations on the formation of Ni2Si confirm previous investigations. The diffusion process at work during the formation of NiSi is discussed in terms of the crystalline anisotropy of this compound and compared to what is known about diffusion in other silicides.

Stability of the dimer structure formed on Si(100) by ultraclean lowpressure chemicalvapor deposition Recrystallization by rapid thermal annealing of implanted lowpressure chemicalvapordeposited amorphous Si films J. Appl. Phys. 62, 4878 (1987); 10.1063/1.338994Observations on the phase transformation and its effect on the resistivity of WSi2 films prepared by lowpressure chemical vapor deposition

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Interfacial reactions and thermal stability of ultrahigh vacuum deposited multilayered Mo/Si structures

The reactions of ruthenium and osmium thin films with their silicon substrates lead to the formation of the following phases: the isomorphous Ru2Si3 and Os2Si3, and OsSi2. Ru2Si3 forms by a diffusion controlled mechanism from approximately 450 to 525 °C; the activation energy is 1.8 eV. Os2Si3 grows by the same process and with the same activation energy as Ru2Si3, but at slightly higher temperatures (for equivalent rates). OsSi2 grows at about 750 °C by a nucleation controlled mechanism. With an alloy of ruthenium containing 33 at.% rhodium, one obtains RuSi, which forms by a diffusion controlled mechanism with an activation energy of 2.4 eV from 400 to 475 °C, and Ru2Si3. In the case of the ruthenium alloy, the formation of Ru2Si3 is not diffusion controlled; the controlling process is akin to a nucleation mechanism. Ru2Si3 and Os2Si3 form by silicon motion. This is also true of OsSi2, but the high formation temperature results in some metal motion also during the formation of that phase. The diffusion processes are discussed on the basis of simple ideas about diffusion in intermetallic compounds. The nucleation processes are shown to occur for the phases OsSi2 and Ru2Si3 (with rhodium), as in other nucleated phases, when the enthalpy contribution to the driving force is close to zero. The observation leads one to anticipate that for most (perhaps all) platinum-like metals the silicides with the highest silicon content should be unstable at low temperatures.