Diffusion-Induced Precipitation in Arsenosilicate Glass (AsSG)

1994 ◽  
Vol 338 ◽  
Author(s):  
Radhika Srinivasan ◽  
Tue Nguyen ◽  
Herbert L. Ho ◽  
Tai D. Nguyen
Keyword(s):  
High Temperature ◽  
Solubility Limit ◽  
Precipitation Process ◽  
Interface Area ◽  
Solid Solubility Limit ◽  
Transmission Electron ◽  
Nucleation Sites ◽  
High Temperature Anneal ◽  
High Concentrations ◽  
Silicon Interface

ABSTRACTDiffusion-induced precipitation in arsenosilicate glass (AsSG) under high temperature anneal is studied by high resolution Transmission Electron Microscopy (TEM), and other techniques. Polycrystalline precipitates of a few hundred angstroms in size have been observed near the interface of AsSG and the silicon substrate, covering the entire interface area after high temperature anneal. It is proposed that high concentrations of arsenic (above the solid solubility limit) precipitate initially at nucleation sites near the AsSG/silicon interface. Further anneal-induced diffusion of arsenic to the interface promotes growth of the precipitates. As a result, the precipitates cover the entire interface area, and impede further As diffusion into the Si substrate. Techniques to avoid the precipitation process without compromising the thermal budget or reduced arsenic diffusion have been explored and will be discussed.

Germanium Incorporation in Silicon Carbide Epitaxial Layers Using Molecular Beam Epitaxy on 4H-SiC Substrates

2019 ◽  
Vol 963 ◽  
pp. 127-130
Author(s):  
Jörg Pezoldt ◽  
Charbel Zgheib ◽  
Thomas Stauden ◽  
Gernot Ecke ◽  
Thomas Kups ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Molecular Beam Epitaxy ◽  
Molecular Beam ◽  
Atomic Layer ◽  
Solubility Limit ◽  
Solid Solubility Limit ◽  
Transmission Electron ◽  
Section Electron ◽  
Heteroepitaxial Layers ◽  
Section Electron Microscopy

Ternary (Si1-xCy)Gex+y solid solutions were grown on Si-face 4H-SiC applying atomic layer molecular beam epitaxy at low temperatures. The grown layers consist of twinned 3C-SiC revealed by cross section electron microscopy. The germanium was incorporated on silicon lattice sites as revealed by atomic location by channeling enhanced microanalysis transmission electron microscopy studies. The Ge concentration of the grown 3C-(Si1-xCy)Gex+y heteroepitaxial layers decreases with increasing growth temperatures, but exceeds the solid solubility limit.

Formation of dense and aligned planar arrangements of Pb nanoparticles at silica/silicon interfaces

2011 ◽  
Vol 1308 ◽  
Author(s):  
Flavia P. Luce ◽  
Felipe Kremer ◽  
Dario F. Sanchez ◽  
Zacarias E. Fabrim ◽  
Shay Reboh ◽  
...  
Keyword(s):  
High Temperature ◽  
Rutherford Backscattering Spectrometry ◽  
Ion Beam ◽  
Aging Treatment ◽  
High Temperature Short Time ◽  
Transmission Electron ◽  
Long Time ◽  
Size Dispersion ◽  
Short Time ◽  
Silicon Interface

ABSTRACTThe ion beam synthesis of Pb nanoparticles (NPs) in silica/silicon films is studied in terms of the combination of a two-step annealing process consisting of a low temperature long time aging treatment followed by a high temperature short time furnace annealing. The samples are analyzed through Rutherford Backscattering Spectrometry and Transmission Electron Microscopy. The aging process leads to the suppression of the classical homogeneous nucleation of metallic Pb NPs in the silica, thus promoting Pb redistribution during the high temperature annealing. This causes the formation of dense bi-dimensional NP arrays located at the silica-silicon interface, presenting small size dispersion.

Microstructural studies by transmission electron microscopy of the formation of ultrathin PtSi layers with novel silicidation processes

1999 ◽  
Vol 14 (6) ◽  
pp. 2577-2587 ◽  
Author(s):  
S. Jin ◽  
H. Bender ◽  
R. A. Donaton ◽  
K. Maex
Keyword(s):  
Electron Beam ◽  
High Temperature ◽  
Thermal Annealing ◽  
Silicon Substrate ◽  
Growth Models ◽  
Schottky Diodes ◽  
Electron Beam Evaporation ◽  
Selective Etch ◽  
Transmission Electron ◽  
High Temperature Anneal

Ultrathin and uniform Pt-silicide layers are prepared by electron beam evaporation on a heated silicon substrate and by magnetron sputtering at room temperature followed by rapid thermal annealing (RTP) and selective etching, respectively. In the electron-beam deposited samples, continuous Pt-silicide layers of 6–8 nm thickness are formed after thermal annealing. The interfaces between the silicide layers and the silicon substrate are not atomically flat. In the case of the sputtered Pt, continuous PtSi layers down to 3 nm thick can be produced by using two-step (low-high temperature) and modified two-step (selective etch and high-temperature anneal) RTP silicidation processes. In one-step (high-temperature) processed samples, PtSi is the dominant phase; meanwhile, a small fraction of Pt12Si5 phase is inhomogeneously distributed in the case of thicker PtSi layers. In the two-step RTP processed samples, a Pt/Pt2Si/PtSi/Si layered structure is formed after the first RTP step. The first anneal step is found to be crucial for the roughness and epitaxy of the final PtSi layer. The best Schottky barrier heights are found to be 0.249 eV for the 3 nm PtSi/p-Si(100) Schottky diodes. The e-beam and the sputtered PtSi layers follow different epitaxial growth models.

scholarly journals Contribution of Local Analysis Techniques for the Characterization of Iron and Alloying Elements in Nitrides: Consequences on the Precipitation Process in Fe–Si and Fe–Cr Nitrided Alloys

Materials ◽  
2018 ◽  
Vol 11 (8) ◽  
pp. 1409
Author(s):  
Hugo Van Landeghem ◽  
Raphaële Danoix ◽  
Mohamed Gouné ◽  
Sylvie Bordère ◽  
Andrius Martinavičius ◽  
...  
Keyword(s):  
Complex Geometry ◽  
Atom Probe ◽  
Local Analysis ◽  
Precipitation Process ◽  
Excess Nitrogen ◽  
Ferritic Matrix ◽  
Chromium Nitrides ◽  
Minor Elements ◽  
Transmission Electron ◽  
Nucleation Sites

Atom Probe Tomography (APT), Transmission Electron Microscopy (TEM), and 3D mechanical calculations in complex geometry and anisotropic strain fields were employed to study the role of minor elements in the precipitation process of silicon and chromium nitrides in nitrided Fe–Si and Fe–Cr alloys, respectively. In nitrided Fe–Si alloys, an original sequence of Si3N4 precipitation was highlighted. Al–N clusters form first and act as nucleation sites for amorphous Si3N4 nitrides. This novel example of particle-simulated nucleation opens a new way to control Si3N4 precipitation in Fe–Si alloys. In nitrided Fe–Cr alloys, both the presence of iron in chromium nitrides and excess nitrogen in the ferritic matrix are unquestionably proved. Only a certain part of the so-called excess nitrogen is shown to be explained by the elastic accommodation of the misfit between nitride and the ferritic matrix. The presence of immobile excess nitrogen trapped at interfaces can be highly suspected.

scholarly journals Structure and Microstructure of Y-doped Strontium Titanate Ceramics

2008 ◽  
Vol 14 (S3) ◽  
pp. 11-12 ◽  
Author(s):  
Alexander Tkach ◽  
Paula M. Vilarinho ◽  
Ian M. Reaney
Keyword(s):  
Electron Microscopy ◽  
Solubility Limit ◽  
Second Phase ◽  
X Ray Diffraction ◽  
Solid Solubility Limit ◽  
Local Composition ◽  
Transmission Electron ◽  
High Dielectric ◽  
Titanate Ceramics ◽  
Structure And Microstructure

High dielectric constant important for functional electronic applications have been reported in the Sr1-1.5xYxTiO3 ceramic system with a maximum value for x = 0.01 coincident with the maximum grain size. This observation points to a possible correlation between the dielectric response and the microstructure of these ceramics. A solid solubility limit around x = 0.04 was reported recently by Fu et al., although the second phase was observed by X-ray diffraction only for x = 0.07. Therefore, the structure, microstructure and local composition of Sr1-1.5xYxTiO3 ceramics (x = 0 − 0.05) prepared by conventional mixed oxide method is investigated in this work by transmission electron microscopy (TEM) and scanning electron microscopy (SEM) equipped with energy dispersive spectroscopy facilities.

Understanding and Controlling Transient Enhanced Dopant Diffusion in Silicon

1994 ◽  
Vol 354 ◽  
Author(s):  
P.A. Stolk ◽  
H.-J. Gossmann ◽  
D.J. Eaglesham ◽  
D.C. Jacobson ◽  
H.S. Luftman ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Activation Energy ◽  
Solubility Limit ◽  
Solid Solubility Limit ◽  
Near Surface ◽  
Enhanced Diffusion ◽  
Defect Clusters ◽  
Transmission Electron ◽  
Junction Formation ◽  
B Doping

AbstractImplanted B and P dopants in Si exhibit transient enhanced diffusion (TED) during initial annealing which arises from the excess interstitials generated by the implant. In order to study the mechanisms of TED, we have used B doping marker layers in Si to probe the injection of interstitials from near-surface, non-amorphizing Si implants during annealing. The in-diffusion of interstitials is limited by trapping at impurities and has an activation energy of -3.5 eV. Substitutional C is the dominant trapping center with a binding energy of 2-2.5 eV. The high interstitial supersaturation adjacent to the implant damage drives substitutional B into metastable clusters at concentrations below the B solid solubility limit. Transmission electron microscopy shows that the interstitials driving TED are emitted from {311} defect clusters in the damage region at a rate which also exhibits an activation energy of 3.6 eV. The population of excess interstitials is strongly reduced by incorporating substitutional C in Si to levels of ∼1019/cm3 prior to ion implantation. This provides a promising method for suppressing TED, thus enabling shallow junction formation in future Si devices through dopant implantation.

Surface morphology of oxygen-implanted wafers

1990 ◽  
Vol 5 (9) ◽  
pp. 1918-1928 ◽  
Author(s):  
Sadao Nakashima ◽  
Katsutoshi Izumi
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
High Temperature ◽  
Surface Morphology ◽  
Oxide Film ◽  
Cross Sectional ◽  
Wafer Temperature ◽  
Oxygen Implantation ◽  
Transmission Electron ◽  
High Temperature Anneal

The surface morphology of SIMOX wafers implanted at 180 keV with doses of 0.4–2.2 ⊠ 101816O+ cm−2 in a temperature range of 400–700 °C has been investigated using transmission electron microscopy (TEM) replica and cross-sectional TEM (XTEM) techniques. Wafer temperature during oxygen implantation strongly affects the morphology. A number of dents are formed on the surface of wafers implanted at temperatures higher than 510 °C with a dose of 1.8 ⊠ 1018 cm−2. Increasing the wafer temperature causes the dents to grow. The dents disappear by a high-temperature anneal of 1260 °C after the implantation. It is found that oxygen implantation through a 50-nm-thick screen oxide film prevents dent formation. A model explaining the dent formation and dent growth is also proposed.

Characterization of Arsenic Implanted Epitaxially Aligned Polysilicon-on-Silicon Films

1987 ◽  
Vol 106 ◽  
Author(s):  
J. L. Hoyt ◽  
E. F. Crabbé ◽  
R. F. W. Pease ◽  
J. F. Gibbons
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
High Temperature ◽  
High Temperature Annealing ◽  
Strong Reduction ◽  
Diffusion Front ◽  
Transmission Electron ◽  
Silicon Interface ◽  
New Evidence

ABSTRACTNonuniformities in the polysilicon-to-silicon interface and in the polysilicon structure are expected to produce a nonuniform diffusion front when arsenic is diffused from polysilicon during epitaxial alignment. Using transmission electron microscopy, we find surprisingly uniform arsenic diffusion fronts in the underlying silicon substrate following high temperature annealing. Several explanations of this result are proposed. We also report new evidence of a strong reduction in the time to achieve complete epitaxial transformation of the polysilicon when the polysilicon thickness is reduced. A corresponding reduction in the associated arsenic penetration depth is demonstrated.

Sign in / Sign up

Export Citation Format

Share Document