Decomposition and nanocrystallization in reactively sputtered amorphous Ta--Si--N thin films
The nanocrystallization process of reactively sputtered thin amorphous Ta--Si--N films is investigated by anomalous small angle x-ray scattering (ASAXS) and x-ray diffraction (XRD). Changes in the microstructure in Ta{sub 40}Si{sub 14}N{sub 46} films, density variations in the amorphous matrix, decomposition, formation, and growth of nanocrystals after vacuum anneals at different temperatures in the range between 800 and 1000{sup o}C are observed and the results of the different techniques are compared. From a Fourier analysis of ASAXS intensities the nanostructure of the investigated ternary system is derived using a model of hard spheres according to Guinier and Fournet. ASAXS investigations indicate that the noncrystalline samples can be described by a monophase fit and the crystallized samples by a bimodal-phase fit, the latter results being consistent with XRD which identifies TaN and Ta{sub 5}Si{sub 3} phases. Detailed analysis shows that TaN nanograins of approximately 2 nm size develop after a decomposition process. Larger grains of Ta{sub 5}Si{sub 3} are observed in addition to the TaN grains if annealing is performed at temperatures higher than 950{sup o}C. The aim of these investigations is to give a generally applicable explanation of the barrier failure mechanism for Ta--Si--N diffusion barriers, which is actually observed at temperatures below the crystallization temperature if the films are used in contact with Cu or Al. {copyright} 2001 American Institute of Physics.
- Sponsoring Organization:
- (US)
- OSTI ID:
- 40230568
- Journal Information:
- Journal of Applied Physics, Vol. 90, Issue 4; Other Information: DOI: 10.1063/1.1388173; Othernumber: JAPIAU000090000004001986000001; 018117JAP; PBD: 15 Aug 2001; ISSN 0021-8979
- Publisher:
- The American Physical Society
- Country of Publication:
- United States
- Language:
- English
Similar Records
In Situ Ramp Anneal X-ray Diffraction Study of Atomic Layer Deposited Ultrathin TaN and Ta 1-x Al x N y Films for Cu Diffusion Barrier Applications
Nanocrystallization kinetics of amorphous Fe{sub 81}B{sub 13.5}Si{sub 3.5}C{sub 2} magnetic ribbons