Study of Pd--Ta on Si(100) using Auger electron spectroscopy, Rutherford backscattering spectrometry, and variable energy positron annihilation

Journal Article · Mon May 01 00:00:00 EDT 1989 · J. Vac. Sci. Technol., A; (United States)

DOI:https://doi.org/10.1116/1.576057· OSTI ID:6185177

van der Kolk, G J; Kuiper, A E.T.; Duchateau, J P.W.B.; Willemsen, M; Nielsen, B; Lynn, K G

The applicability of Pd/sub x/Ta/sub 1-//sub x/ as a diffusion barrier on Si has been investigated. For this purpose Pd/sub x/Ta/sub 1-//sub x/ films of 200-nm thickness (x ranges from 0 to 1) were deposited on Si(100), and the reaction between overlayer and substrate was studied as a function of temperature. Interaction was found to occur at temperatures increasing with the Ta content. The as-deposited Pd/sub x/Ta/sub 1-//sub x/ films with 0.2less than or equal toxless than or equal to0.6 were found to be amorphous. The amorphous phase had a higher reaction temperature than the crystalline one, causing a discontinuous step in the reaction temperature. Rutherford backscattering spectrometry spectra revealed that for the Pd-rich compositions, first a stoichiometric Pd/sub 2/Si layer formed underneath a pure Ta layer. At higher temperatures TaSi/sub 2/ formed at the surface. For Ta-rich compositions Pd/sub 2/Si formed first as well; however, the reaction temperature was so high that Pd/sub 2/Si grains formed in a Si matrix. The defect density of the Ta layer, which remained after outdiffusion of Pd, was investigated using variable energy positron annihilation. The defect concentration is very high, as deduced from the trapped positron fraction. A model is presented that describes the composition dependence of the reaction temperature.

• Research Organization: Philips Research Laboratories, 5600 JA Eindhoven, the Netherlands
• OSTI ID: 6185177
• Journal Information: J. Vac. Sci. Technol., A; (United States), Vol. 7:3
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
PALLADIUM ALLOYS
DEPOSITION
SILICON
COATINGS
TANTALUM BASE ALLOYS
AMORPHOUS STATE
CRYSTAL STRUCTURE
DIFFUSION BARRIERS
INTERFACES
RUTHERFORD SCATTERING
SUBSTRATES
THIN FILMS
TRANSMISSION ELECTRON MICROSCOPY
X-RAY DIFFRACTION
ALLOYS
COHERENT SCATTERING
DIFFRACTION
ELASTIC SCATTERING
ELECTRON MICROSCOPY
ELEMENTS
FILMS
MICROSCOPY
PLATINUM METAL ALLOYS
SCATTERING
SEMIMETALS
TANTALUM ALLOYS
360102* - Metals & Alloys- Structure & Phase Studies