Dopant Transport in Tungsten Silicide Buried Layers for Application in SSOI

2019 ◽  
Vol 28 (1) ◽  
pp. 331-341
Author(s):  
Shengzhou Liao ◽  
Michael Bain ◽  
Paul Baine ◽  
John Montgomery ◽  
David W. McNeill ◽  
...  
Keyword(s):  
Tungsten Silicide ◽  
Buried Layers

Morphology of Si/Tungsten-Silicide/Si Interlayers

1991 ◽  
Vol 238 ◽  
Author(s):  
N. David Theodore ◽  
F. Secco d'Aragona ◽  
Scott Blackstone
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Silicon Dioxide ◽  
Vapor Deposition ◽  
Chemical Vapor ◽  
Semiconductor Technology ◽  
Tungsten Silicide ◽  
Transmission Electron ◽  
Buried Layers ◽  
Individual Grains

ABSTRACTTungsten and tungsten-silicides are of interest for semiconductor technology because of their refractory nature, low electrical-resistivity and high electromigration-resistance. This paper presents the first formation of buried tungsten-silicide layers in silicon, by proximity adhesion. The interlayers, created by a combination of chemical vapor-deposition (CVD) and proximity-adhesion were studied using transmission electron-microscopy (TEM). The behavior of the layers in the presence and absence of an adjacent silicon-dioxide interlayer was also investigated. Buried suicide layers were successfully formed with or without the adjacent silicon-dioxide. The suicide formed continuous layers with single grains encompassing the width of the interlayer. Individual grains were globular, with cusps at grain boundaries. This caused interlayer-thicknesses to be non-uniform, with lower thickness values being present at the cusps. Occasional voids were observed at grain-boundary cusps. The voids were smaller and less frequent in the presence of an adjacent oxide-layer, due to flow of the oxide during proximity adhesion. Electron-diffraction revealed a predominance of tungsten-disilicide in the interlayers, with some free tungsten being present. Stresses in the suicide layers caused occasional glide dislocations to propagate into the silicon substrate beneath the interlayers. The dislocations propagate only ∼100 nm into the substrate and therefore should not be detrimental to use of the buried layers. Occasional precipitates were observed at the end of glide-loops. These possibly arise due to excess tungsten from the interlayer diffusing down the glide dislocation to finally precipitate out as tungsten-silicide.

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.

TEM characterization of WSix films

1994 ◽  
Vol 52 ◽  
pp. 848-849
Author(s):  
V. C. Kannan ◽  
S. M. Merchant ◽  
R. B. Irwin ◽  
A. K. Nanda ◽  
M. Sundahl ◽  
...  
Keyword(s):  
Integrated Circuits ◽  
Vapor Deposition ◽  
High Purity ◽  
Physical Vapor Deposition ◽  
Thermal Treatments ◽  
Rapid Thermal Anneal ◽  
Tungsten Silicide ◽  
Tem Characterization ◽  
Metal Silicides

Metal silicides such as WSi2, MoSi2, TiSi2, TaSi2 and CoSi2 have received wide attention in recent years for semiconductor applications in integrated circuits. In this study, we describe the microstructures of WSix films deposited on SiO2 (oxide) and polysilicon (poly) surfaces on Si wafers afterdeposition and rapid thermal anneal (RTA) at several temperatures. The stoichiometry of WSix films was confirmed by Rutherford Backscattering Spectroscopy (RBS). A correlation between the observed microstructure and measured sheet resistance of the films was also obtained.WSix films were deposited by physical vapor deposition (PVD) using magnetron sputteringin a Varian 3180. A high purity tungsten silicide target with a Si:W ratio of 2.85 was used. Films deposited on oxide or poly substrates gave rise to a Si:W ratio of 2.65 as observed by RBS. To simulatethe thermal treatments of subsequent processing procedures, wafers with tungsten silicide films were subjected to RTA (AG Associates Heatpulse 4108) in a N2 ambient for 60 seconds at temperatures ranging from 700° to 1000°C.

Properties of tungsten silicide thin films obtained by magnetron sputtering of composite cast targets

1997 ◽  
Author(s):  
V.G. Glebovsky ◽  
S.N. Ermolov ◽  
V.N. Motuzenko ◽  
E.D. Shtinov
Keyword(s):  
Thin Films ◽  
Magnetron Sputtering ◽  
Tungsten Silicide

Formation and control of boron buried layers in silicon using an excimer laser

1995 ◽  
Vol 16 (1) ◽  
pp. 14-16 ◽  
Author(s):  
G. Verma ◽  
A. Slaoui ◽  
S. Talwar ◽  
T.W. Sigmon
Keyword(s):  
Excimer Laser ◽  
Buried Layers ◽  
And Control

An XPS study of XeF2 dry etching of tungsten silicide

1988 ◽  
Vol 197 (1-2) ◽  
pp. 99-108 ◽  
Author(s):  
E. Grossman ◽  
A. Bensaoula ◽  
A. Ignatiev
Keyword(s):  
Dry Etching ◽  
Tungsten Silicide ◽  
Xps Study

Characterization of tungsten silicide (WSix) film grown by chemical vapor deposition (CVD)

1999 ◽  
Author(s):  
Fazla R. M. Hossain ◽  
Satheesh Ambadi ◽  
Richard Winer ◽  
Ken Kitt ◽  
Carlos Garcia ◽  
...  
Keyword(s):  
Chemical Vapor Deposition ◽  
Vapor Deposition ◽  
Chemical Vapor ◽  
Tungsten Silicide
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