CXLII. On the application of eigenfunction expansions to the problem of the thermal instability of a fluid sphere heated within

1955 ◽  
Vol 46 (383) ◽  
pp. 1310-1327 ◽  
Author(s):  
G.E. Backus
Keyword(s):  
Thermal Instability ◽  
Fluid Sphere ◽  
Eigenfunction Expansions

On the thermal instability of a rotating-fluid sphere containing heat sources

1968 ◽  
Vol 263 (1136) ◽  
pp. 93-117 ◽  
Keyword(s):  
Velocity Vector ◽  
Thermal Instability ◽  
Asymptotic Theory ◽  
Expansion Method ◽  
Fluid Sphere ◽  
Uniform Density ◽  
Heat Sources ◽  
Rotating Fluid ◽  
Angular Velocity Vector ◽  
Axis Of Rotation

The theory of marginal convection in a uniformly rotating, self-gravitating, fluid sphere, of uniform density and containing a uniform distribution of heat sources, is developed to embrace modes of convection which are asymmetric with respect to the axis of rotation. It is shown that these modes are the most unstable, except for the smallest Taylor numbers, T (a measure of the rotation rate); i.e. for any T and o) (Prandtl number), the lowest Rayleigh number (a measure of the temperature gradients in the sphere) is associated with an asymmetric motion. This is demonstrated both by an expansion method suitable for small T, and by asymptotic theory for T oo. For large T, the eigenmode most easily excited is small in amplitude everywhere except near a cylindrical surface, of radius about half that of the sphere, and coaxial with the diameter parallel to the angular velocity vector.

TEM study of Cosi2 formation via annealing of Co-Ti bilayers on Si

1995 ◽  
Vol 53 ◽  
pp. 464-465
Author(s):  
N. David Theodore ◽  
Andre Vantomme ◽  
Peter Crazier
Keyword(s):  
Thermal Instability ◽  
Lattice Mismatch ◽  
Field Effect Transistors ◽  
Contact Layer ◽  
Interface Roughness ◽  
Oxide Semiconductor ◽  
Surface Layers ◽  
Silicide Layer ◽  
Small Lattice ◽  
Buried Layers

Contact is typically made to source/drain regions of metal-oxide-semiconductor field-effect transistors (MOSFETs) by use of TiSi2 or CoSi2 layers followed by AI(Cu) metal lines. A silicide layer is used to reduce contact resistance. TiSi2 or CoSi2 are chosen for the contact layer because these silicides have low resistivities (~12-15 μΩ-cm for TiSi2 in the C54 phase, and ~10-15 μΩ-cm for CoSi2). CoSi2 has other desirable properties, such as being thermally stable up to >1000°C for surface layers and >1100°C for buried layers, and having a small lattice mismatch with silicon, -1.2% at room temperature. During CoSi2 growth, Co is the diffusing species. Electrode shorts and voids which can arise if Si is the diffusing species are therefore avoided. However, problems can arise due to silicide-Si interface roughness (leading to nonuniformity in film resistance) and thermal instability of the resistance upon further high temperature annealing. These problems can be avoided if the CoSi2 can be grown epitaxially on silicon.

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