Morphological instability of NiSi1−uGeu on single-crystal and polycrystalline Si1−xGex

The morphological stability of NiSi1−uGeu ternary alloy films formed by reacting Ni with single-crystal (sc) and polycrystalline (poly) Si1−xGeu is studied (u can be different from x). The agglomeration of NiSi1−uGeu films on Si0.7Ge0.3 occurs at 550°C after rapid thermal processing for 30 s, independently of the crystallinity of the Si1−xGeu. This behavior distinctly different from NiSi: NiSi films on poly-Si display a poorer morphological stability and degrade at lower temperatures than NiSi on sc-Si. On strained Si1−xGex, the presence of Ge simultaneously gives rise to two effects of different origin: mechanical and thermodynamic. The main driving forces behind the agglomeration of NiSi1−uGeu on sc-Si1−xGex are found to be the stored strain energy in the Si1−xGex and the larger (absolute) free energy of formation of NiSi compared to NiGe. The latter constitutes the principal driving force behind the agglomeration of NiSi1−uGeu on poly-Si1−xGex and is not affected by the degree of crystallinity of Si1−x...

[1]  J. W. Mayer,et al.  Interaction of metal layers with polycrystalline Si , 1975 .

[2]  L. J. Chen,et al.  Enhanced growth of low-resistivity NiSi on epitaxial Si0.7Ge0.3 on (001)Si with a sacrificial amorphous Si interlayer , 2003 .

[3]  J. E. E. Baglin,et al.  Formation of thin films of NiSi: Metastable structure, diffusion mechanisms in intermetallic compounds , 1984 .

[4]  S. Zhang.  Nickel-based contact metallization for SiGe MOSFETs: progress and challenges , 2003 .

[5]  F. d'Heurle,et al.  Morphological Instabilities in Bilayers Incorporating Polycristalline Silicon , 1992 .

[6]  C. Petersson,et al.  Work function of boron-doped polycrystalline Si/sub x/Ge/sub 1-x/ films , 1997, IEEE Electron Device Letters.

[7]  T. Araki,et al.  The stability of ordered structures in SiGe films examined by strain-energy calculations , 1997 .

[8]  Shi-Li Zhang,et al.  Increased nucleation temperature of NiSi2 in the reaction of Ni thin films with Si1−xGex , 2002 .

[9]  Kenneth P. Rodbell,et al.  Microstructure control in semiconductor metallization , 1997 .

[10]  T. Seong,et al.  Effect of a Mo Interlayer on the Electrical and Structural Properties of Nickel Silicides , 2003 .

[11]  Hiroshi Iwai,et al.  NiSi salicide technology for scaled CMOS , 2002 .

[12]  C. Thompson.  Secondary grain growth in thin films of semiconductors: Theoretical aspects , 1985 .

[13]  Robert Sinclair,et al.  Modeling of agglomeration in polycrystalline thin films : application to TiSi2 on a silicon substrate , 1992 .

[14]  S. Iyer,et al.  Interfacial Reaction Between Ni and MBE‐Grown SiGe Alloy , 1988 .

[15]  Shi-Li Zhang,et al.  Enhanced phase stability and morphological stability of Ni(Si,Ge) on strained Si0.8Ge0.2 , 2003 .

[16]  F. d'Heurle,et al.  Kinetics of formation of silicides: A review , 1986 .

[17]  Hua-Chou Tseng,et al.  Study of nickel silicide contact on Si/Si1-xGex , 2003, IEEE Electron Device Letters.

[18]  F. d'Heurle,et al.  Morphological instabilities of nickel and cobalt silicides on silicon , 1991 .

[19]  Bernard,et al.  Strain energy and stability of Si-Ge compounds, alloys, and superlattices. , 1991, Physical review. B, Condensed matter.

[20]  F. D. Boer.  Cohesion in Metals: Transition Metal Alloys , 1989 .

[21]  Shi-Li Zhang,et al.  Morphological and phase stability of nickel–germanosilicide on Si1−xGex under thermal stress , 2002 .