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The barrier effect of a WxTa(1-x) nanolayer on formation of single-texture CoSi2 on Si(1 0 0)

Akhavan, O ; Sharif University of Technology | 2006

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  1. Type of Document: Article
  2. DOI: 10.1088/0268-1242/21/8/034
  3. Publisher: 2006
  4. Abstract:
  5. We have studied the phase formation of a CoSi2 layer by solid-state reaction of ternary Co/WxTa(1-x)/Si(1 0 0) systems. The effect of cosputtered WxTa(1-x) nanometric interlayers, with different values of x (0, 0.25, 0.5, 0.75 and 1), on the degree of texturing of a CoSi2 layer and disilicide formation of the refractory metals has been investigated. The annealed samples, in a temperature range of 400-1000 °C, were analysed by x-ray diffraction, sheet resistance measurement, scanning electron microscopy, and energy-dispersive x-ray techniques. Using W0.25Ta0.75 and W interlayers, the best (1 0 0) texture of the CoSi2 layer with a thermal stability in the range of 900-1000 °C was produced. In the Co/W/Si system, a considerable amount of WSi2 is formed as a cap layer, while a nearly negligible amount of refractory metal disilicide is formed in the Co/W 0.25Ta0.75/Si system. Study of the growth kinetics shows that the activation energies of CoSi2 formation in these two systems are greater than those of other thermally stable systems. The mechanism of single-texture formation of a nanothickness CoSi2 layer has been explained on the basis of controlling Co-Si interdiffusion via the intermediate layers. © 2006 IOP Publishing Ltd
  6. Keywords:
  7. Annealing ; Scanning electron microscopy ; Semiconducting silicon ; Temperature distribution ; Ternary systems ; X ray diffraction analysis ; Barrier effect ; Disilicide ; Solid state reactions ; Temperature range ; Crystalline materials
  8. Source: Semiconductor Science and Technology ; Volume 21, Issue 8 , 2006 , Pages 1181-1192 ; 02681242 (ISSN)
  9. URL: https://iopscience.iop.org/article/10.1088/0268-1242/21/8/034/meta