TY - GEN
T1 - The interfacial diffusion zone in magnetron sputtered Ni-Ti thin films deposited on different Si substrates studied by HR-TEM
AU - Martins, Rui Miguel dos Santos
AU - Beckers, Manfred
AU - Mücklich, Arndt
AU - Schell, Norbert
AU - Silva, Rui Jorge Cordeiro
AU - Braz Fernandes, Francisco Manuel
AU - Mahesh, Karimbi Koosappa
PY - 2008
Y1 - 2008
N2 - Ni-Ti Shape Memory Alloy thin films are suitable materials for microelectromechanical devices. During the deposition of Ni-Ti thin films on Si substrates, there exist interfacial diffusion and chemical interactions at the interface due to the high temperature processing necessary to crystallize the film. For the present study, Ni-Ti thin films were prepared by magnetron co-sputtering from Ni-Ti and Ti targets in a specially designed chamber mounted on the 6-circle goniometer of the ROssendorf BeamLine (ROBL-CRG) at ESRF, Grenoble (France). The objective of this study has been to investigate the interfacial structure resulting from depositions (at a temperature of ≈470°C) on different substrates: naturally oxidized Si(100), Si(111) and poly-Si substrates. A detailed High-Resolution TEM analysis of the interfacial structure has been performed. When Ni-Ti is deposited on Si(100) substrate, a considerable diffusion of Ni into the substrate takes place, resulting in the growth of semi-octaeder A-NiSi2 silicide. In the case of Ni-Ti deposited on Si(111), there appears an uniform thickness plate, due to the alignment between substrate orientation and the [111]-growth front. For Ni-Ti deposited on poly-Si, the diffusion is inhomogeneous. Preferential diffusion is found along the columnar grains of poly-Si, which are favourably aligned for Ni diffusion. These results show that for the Ni-Ti/Si system, the morphology of the diffusion interface is strongly dependent on the type of substrates.
AB - Ni-Ti Shape Memory Alloy thin films are suitable materials for microelectromechanical devices. During the deposition of Ni-Ti thin films on Si substrates, there exist interfacial diffusion and chemical interactions at the interface due to the high temperature processing necessary to crystallize the film. For the present study, Ni-Ti thin films were prepared by magnetron co-sputtering from Ni-Ti and Ti targets in a specially designed chamber mounted on the 6-circle goniometer of the ROssendorf BeamLine (ROBL-CRG) at ESRF, Grenoble (France). The objective of this study has been to investigate the interfacial structure resulting from depositions (at a temperature of ≈470°C) on different substrates: naturally oxidized Si(100), Si(111) and poly-Si substrates. A detailed High-Resolution TEM analysis of the interfacial structure has been performed. When Ni-Ti is deposited on Si(100) substrate, a considerable diffusion of Ni into the substrate takes place, resulting in the growth of semi-octaeder A-NiSi2 silicide. In the case of Ni-Ti deposited on Si(111), there appears an uniform thickness plate, due to the alignment between substrate orientation and the [111]-growth front. For Ni-Ti deposited on poly-Si, the diffusion is inhomogeneous. Preferential diffusion is found along the columnar grains of poly-Si, which are favourably aligned for Ni diffusion. These results show that for the Ni-Ti/Si system, the morphology of the diffusion interface is strongly dependent on the type of substrates.
KW - High-resolution TEM
KW - Interfacial diffusion
KW - Ni-Ti thin films
KW - Shape memory alloy
UR - http://www.scopus.com/inward/record.url?scp=60349100285&partnerID=8YFLogxK
U2 - 10.4028/www.scientific.net/msf.587-588.820
DO - 10.4028/www.scientific.net/msf.587-588.820
M3 - Conference contribution
SN - 9780878493739
SN - 0878493735
T3 - Materials Science Forum
SP - 820
EP - 823
BT - Advanced Materials Forum IV
A2 - Marques, António Torres
A2 - Silva, António Fernando
A2 - Baptista, António Paulo Monteiro
A2 - Alves, Fernando Jorge Lino
A2 - Sá, Carlos
A2 - Malheiros, Luís Filipe
A2 - Vieira, Manuel
PB - Trans Tech Publications
CY - Zurich
T2 - Advanced Materials Forum IV - Selected, peer reviewed papers from the 4th International Materials Symposium Materiais 2007 and 8th Encontro da Sociedade Portuguesa de Materiais - SPM
Y2 - 1 April 2007 through 4 April 2007
ER -