Thermal stability of amorphous Ni-Nb thin films for use as diffusion barriers

Conference · Thu Jan 01 04:00:00 EST 1987

OSTI ID:5614820

Farrens, S N; Perepezko, J H; Doyle, B L; Lee, S R

The usefulness of amorphous metal thin films as diffusion barriers or as primary metallizations is limited by the thermal stability of the amorphous material to crystallization. The interdiffusion and crystallization reactions between amorphous Ni-Nb alloy films and Si substrates and several overlayer metals have been monitored by x-ray diffraction and high resolution Rutherford backscattering spectroscopy. Free standing amorphous thin films of Ni-Nb alloys crystallize in one hour at temperatures between 600-625/sup 0/C and show little dependence of the crystallization temperature, T/sub x/, on composition over the range from 30-80 at. % Ni. However, in films that are sputter deposited onto Si substrates T/sub x/ tends to increase with increasing Nb composition. Ni/sub 60/Nb/sub 40/ samples without overlayers crystallize at 650-700/sup 0/C. Enhancement of the thermal stability to 700-750/sup 0/C is achieved with a Nb overlayer. In contrast, a Ni overlayer can reduce T/sub x/ to 450/sup 0/C. At the film/substrate interface silicide formation reactions with Ni from the film contribute to a destabilization of the amorphous alloy. The modification of T/sub x/ with Ni, Nb, and other overlayers appears to be related to changes in the reaction kinetics associated with penetration of the overlayer into the film. 7 refs., 2 figs., 1 tab.

• Research Organization: Sandia National Labs., Albuquerque, NM (USA); Wisconsin Univ., Madison (USA)
• DOE Contract Number: AC04-76DP00789; FG02-84ER45069
• OSTI ID: 5614820
• Report Number(s): SAND-88-1525C; CONF-871124-29; ON: DE88003936
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
360102* -- Metals & Alloys-- Structure & Phase Studies
360104 -- Metals & Alloys-- Physical Properties
ALLOYS
AMORPHOUS STATE
ANNEALING
COHERENT SCATTERING
CRYSTALLIZATION
DEPOSITION
DIFFRACTION
DIFFUSION
DIFFUSION BARRIERS
ELASTIC SCATTERING
ELEMENTS
FILMS
HEAT TREATMENTS
METALS
NICKEL ALLOYS
NICKEL BASE ALLOYS
NIOBIUM
NIOBIUM ALLOYS
PHASE TRANSFORMATIONS
PHYSICAL PROPERTIES
RUTHERFORD SCATTERING
SCATTERING
SEMIMETALS
SILICON
TEMPERATURE EFFECTS
THERMODYNAMIC PROPERTIES
THIN FILMS
TRANSITION ELEMENTS
TRANSITION TEMPERATURE
X-RAY DIFFRACTION