Accession Number : ADP008058

Title :   Interdiffusion Kinetics in Mo/Si Multilayers,

Corporate Author : LAWRENCE LIVERMORE NATIONAL LAB CA

Personal Author(s) : Rosen, R.S. ; Stearns, D.G. ; Viliardos, M.A. ; Kassner, M.E. ; Vernon, S.P.

Report Date : 05 MAR 1992

Pagination or Media Count : 3

Abstract : Mo/Si multilayers (ML's) are attractive for x-ray optics relatively high associated reflectivity. However, the reflectivity is known to decrease with the formation of diffuse interlayer regions resulting from interdiffusion at the Mo-Si interfaces 1-2. Most of the previous studies have reported interdiffusion coefficients 1-5 and effective activation energies 2-4 over a range of temperature assuming that the interdiffusion coefficient is invariant with annealing time. At temperatures of 560-580 deg C, hexagonal molybdenum-disilicide (h-MoSi2) grows with a square root time dependence at the Mo-Si interface 6. This suggests diffusion-limited growth with a time-invariant interdiffusion coefficient. However, at temperatures of 300-400 deg C, the interlayer structure is known to change with annealing time from amorphous to crystalline 1-3, suggesting the possibility that the rate-controlling mechanism(s) for interdiffusion may also change with annealing time and/or temperature. Therefore, it is the objective of this study to perform a series of annealing treatments of Mo/Si ML's at temperatures lower than those previously reported to determine the Mo-Si interdiffusion kinetics as a function of time.

Descriptors :   *DIFFUSION, *KINETICS, *MOLYBDENUM, *SILICON, *LAYERS, ACTIVATION, ACTIVATION ENERGY, ANNEALING, COEFFICIENTS, FUNCTIONS, INTERFACES, OPTICS, RATES, REFLECTIVITY, REGIONS, STRUCTURES, TEMPERATURE, TIME, TIME DEPENDENCE, X RAYS, CRYSTAL STRUCTURE, SPUTTERING, DEPOSITION, WAFERS, SINGLE CRYSTALS, X RAY DIFFRACTION.

Subject Categories : Properties of Metals and Alloys
      Mechanics
      Nuclear Physics & Elementary Particle Physics

Distribution Statement : APPROVED FOR PUBLIC RELEASE