Growth of CoSi{sub 2} on Si(001) by reactive deposition epitaxy
- Materials Science Department and the Frederick Seitz Materials Research Laboratory, University of Illinois, 104 South Goodwin Avenue, Urbana, Illinois 61801 (United States)
CaF{sub 2}-structure CoSi{sub 2} layers were formed on Si(001) by reactive deposition epitaxy (RDE) and compared with CoSi{sub 2} layers obtained by conventional solid phase growth (SPG). In both sets of experiments, Co was deposited by ultrahigh-vacuum magnetron sputtering and CoSi{sub 2} formed at 600 deg. C. However, in the case of RDE, CoSi{sub 2} formation occurred during Co deposition while for SPG, Co was deposited at 25 deg. C and silicidation took place during subsequent annealing. X-ray diffraction pole figures and transmission electron microscopy results demonstrate that RDE CoSi{sub 2} layers are epitaxial with a cube-on-cube relationship (001){sub CoSi{sub 2}} parallel (001){sub Si} and [100]{sub CoSi{sub 2}} parallel[100]{sub Si}. In contrast, SPG films are polycrystalline with an average grain size of {approx_equal}1000 A and a mixed 111/002/022/112 orientation. We attribute the striking difference to rapid Co diffusion into the Si(001) substrate during RDE for which the high Co/Si reactivity gives rise to a flux-limited reaction resulting in the direct formation of the disilicide phase. In contrast, sequential nucleation and transformation among increasingly Si-rich phases--from orthorhombic Co{sub 2}Si to cubic CoSi to CoSi{sub 2}--during SPG results in polycrystalline layers with a complex texture.
- OSTI ID:
- 20668212
- Journal Information:
- Journal of Applied Physics, Vol. 97, Issue 4; Other Information: DOI: 10.1063/1.1774263; (c) 2005 American Institute of Physics; Country of input: International Atomic Energy Agency (IAEA); ISSN 0021-8979
- Country of Publication:
- United States
- Language:
- English
Similar Records
High-flux low-energy ({congruent}20 eV) N{sup +}{sub 2} ion irradiation during TiN deposition by reactive magnetron sputtering: Effects on microstructure and preferred orientation
Formation of single-crystal CoSi{sub 2} buffer layers on Si (100) substrates by high dose Co ion implantation for the deposition of YBa{sub 2}Cu{sub 3}O{sub 7{minus}x} thin films