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

Journal Article · Mon May 01 04:00:00 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), Journal Name: J. Vac. Sci. Technol., A; (United States) Vol. 7:3; ISSN JVTAD
• Country of Publication: United States
• Language: English

Related Subjects

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