Self-aligned sources for dislocation nucleation: The key to low threading dislocation densities in compositionally graded thin films grown at low temperature

1994 ◽  
Vol 72 (6) ◽  
pp. 876-879 ◽  
Author(s):  
F. K. LeGoues
Keyword(s):  
Thin Films ◽  
Low Temperature ◽  
Dislocation Nucleation ◽  
Threading Dislocation ◽  
Dislocation Densities

Relaxed Ge0.9Si0.1 alloy layers with low threading dislocation densities grown on low-temperature Si buffers

1998 ◽  
Vol 72 (24) ◽  
pp. 3160-3162 ◽  
Author(s):  
C. S. Peng ◽  
Z. Y. Zhao ◽  
H. Chen ◽  
J. H. Li ◽  
Y. K. Li ◽  
...  
Keyword(s):  
Low Temperature ◽  
Threading Dislocation ◽  
Dislocation Densities

scholarly journals Single-Crystalline Si1−xGex (x = 0.5~1) Thin Films on Si (001) with Low Threading Dislocation Density Prepared by Low Temperature Molecular Beam Epitaxy

2019 ◽  
Vol 9 (9) ◽  
pp. 1772
Author(s):  
Gu ◽  
Zhao ◽  
Ye ◽  
Deng ◽  
Lu
Keyword(s):  
Thin Films ◽  
Molecular Beam Epitaxy ◽  
Low Temperature ◽  
Dislocation Density ◽  
Molecular Beam ◽  
Strain Relaxation ◽  
Relaxation Mechanism ◽  
Threading Dislocation ◽  
Threading Dislocation Density ◽  
Typical Strain

Single-crystalline Si1−xGex thin films on Si (100) with low threading dislocation density (TDD) are highly desired for semiconductor industrials. It is challenging to suppress the TDD since there is a large mismatch (4.2%) between Ge and Si—it typically needs 106–107/cm2 TDD for strain relaxation, which could, however, cause device leakage under high voltage. Here, we grew Si1−xGex (x = 0.5–1) films on Si (001) by low temperature molecular beam epitaxy (LT-MBE) at 200 °C, which is much lower than the typical temperature of 450–600 °C. Encouragingly, the Si1−xGex thin films grown by LT-MBE have shown a dramatically reduced TDD down to the 103–104/cm2 level. Using transmission electron microscopy (TEM) with atomic resolution, we discovered a non-typical strain relaxation mechanism for epitaxial films grown by LT-MBE. There are multiple-layered structures being introduced along out-of-plane-direction during film growth, effectively relaxing the large strain through local shearing and subsequently leading to an order of magnitude lower TDD. We presented a model for the non-typical strain relaxation mechanism for Si1−xGex films grown on Si (001) by LT-MBE.

Optimization of SiGe Graded Buffer Defectivity and Throughput by Means of High Growth Temperature and Pre-Threaded Substrates

2005 ◽  
Vol 891 ◽  
Author(s):  
Matthew Erdtmann ◽  
Matthew T. Currie ◽  
Joseph C. Woicik ◽  
David Black
Keyword(s):  
Growth Temperature ◽  
High Growth ◽  
Dislocation Nucleation ◽  
Threading Dislocation ◽  
Threading Dislocations ◽  
Trade Off ◽  
Dislocation Glide ◽  
Si Substrates ◽  
High Growth Temperature ◽  
Dislocation Densities

ABSTRACTDislocation glide kinetics dictate in relaxed graded buffers a fundamental opposition between the defectivity and throughput. For state-of-the-art Si-based applications, the trade-off between defect level and wafer cost (inversely related to throughput) has made the insertion of SiGe graded buffers into production difficult. We aim to mitigate the trade-off by reporting two advances that enable simultaneous improvements in both defectivity and throughput. The first is use of a high growth temperature to allow very fast dislocation glide velocities and growth rates as high as 1.0 μm/min. The second is the use of “pre-threaded” Si substrates, substrates with an elevated density of threading dislocations. By having dislocation nucleation controlled by uniformly distributed substrate threading dislocations, instead of unpredictable heterogeneous sources, impediments to dislocation glide, such as dislocation bundles and pile-ups, are reduced. By incorporating both advances into SiGe graded buffer epitaxy, dislocation pile-up densities are reduced by nearly three orders of magnitude, threading dislocation densities are reduced by a factor of 7.4×, and wafer throughput is increased at least 33%.

Low Threading Dislocation Densities in Thick, Relaxed Si1−xGex Buffer Layers

1991 ◽  
Vol 220 ◽  
Author(s):  
C. G. Tuppen ◽  
C. J. Gibbings ◽  
M. Hockly
Keyword(s):  
Dislocation Density ◽  
Dislocation Nucleation ◽  
Buffer Layers ◽  
Threading Dislocation ◽  
Direct Deposition ◽  
Dislocation Densities ◽  
Defect Densities

ABSTRACTA series of relaxed Si1−xGex alloy layers with germanium contents up to 70% has been deposited on silicon. Although direct deposition ot these highly mismatched layers on silicon gave dislocation densities of 109-1010cm2 and poor morphology, it was found that the use of a linear grade enabled completely relaxed Si.3Ge.7 layers with defect densities of ∼3.105cm−2 to be obtained. However, if the grading was too rapid the dislocation density was much higher. The role of dislocation nucleation and propagation in determining the required thickness of graded layer is discussed.

Significance of a Nucleation Layer in Inhibiting Interfacial Pitting in InAs Films Grown by Two-Step MOVCD on (100) Inp Substrates

1993 ◽  
Vol 312 ◽  
Author(s):  
A. K. Ballal ◽  
L. Salamanca-Riba ◽  
D. L. Partin
Keyword(s):  
Electron Microscopy ◽  
Low Temperature ◽  
Substrate Surface ◽  
Threading Dislocation ◽  
High Electron ◽  
Nucleation Layer ◽  
Transmission Electron ◽  
Dislocation Densities ◽  
Temperature Deposition ◽  
Higher Temperature

AbstractIn this paper, we study the significance of a low temperature nucleation layer and its role in inhibiting interfacial pitting vapor deposition. Transmission electron microscopy and scanning electron microscopy studies show that severe interfacial pitting occurs for thin nucleation layers of average thicknesses of 200Å and 400Å. For these average nucleation layer thicknesses we have found that the InAs islands do not cover the entire substrate surface during the low temperature deposition. Hence, when the film is heated to a higher temperature for the growth of the remainder of the film severe pitting at the heterointerface is produced. The thermal etchpits are sources of threading dislocations, which propagate to the surface of the film. For thicker nucleation layers we observe no interfacial pitting. Our studies show that there is an optimum nucleation layer thickness for which high quality InAs films with reduced threading dislocation densities and relatively high electron mobilities are obtained. Both electrical and structural studies suggest that ∼ 800Å is an optimum thickness of the low temperature nucleation layer.

Observation by HVEM of the martensite transformation and the superconducting transition in Nb3Sn

1988 ◽  
Vol 46 ◽  
pp. 788-789
Author(s):  
M. A. Kirk ◽  
M. C. Baker ◽  
B. J. Kestel ◽  
H. W. Weber
Keyword(s):  
Thin Films ◽  
Low Temperature ◽  
Superconducting State ◽  
Martensite Transformation ◽  
Sputter Deposition ◽  
Diffusion Reaction ◽  
Solute Diffusion ◽  
Superconducting Transition ◽  
Twin Boundaries ◽  
Martensite Structure

It is well known that a number of compound superconductors with the A15 structure undergo a martensite transformation when cooled to the superconducting state. Nb3Sn is one of those compounds that transforms, at least partially, from a cubic to tetragonal structure near 43 K. To our knowledge this transformation in Nb3Sn has not been studied by TEM. In fact, the only low temperature TEM study of an A15 material, V3Si, was performed by Goringe and Valdre over 20 years ago. They found the martensite structure in some foil areas at temperatures between 11 and 29 K, accompanied by faults that consisted of coherent twin boundaries on {110} planes. In pursuing our studies of irradiation defects in superconductors, we are the first to observe by TEM a similar martensite structure in Nb3Sn.Samples of Nb3Sn suitable for TEM studies have been produced by both a liquid solute diffusion reaction and by sputter deposition of thin films.

Low temperature charge carrier hopping transport mechanism in vanadium oxide thin films grown using pulsed dc sputtering

2009 ◽  
Vol 94 (22) ◽  
pp. 222110 ◽  
Author(s):  
S. S. N. Bharadwaja ◽  
C. Venkatasubramanian ◽  
N. Fieldhouse ◽  
S. Ashok ◽  
M. W. Horn ◽  
...  
Keyword(s):  
Thin Films ◽  
Low Temperature ◽  
Charge Carrier ◽  
Vanadium Oxide ◽  
Transport Mechanism ◽  
Oxide Thin Films ◽  
Hopping Transport ◽  
Dc Sputtering ◽  
Pulsed Dc ◽  
Vanadium Oxide Thin Films

A novel low-temperature growth of uniform CuInS2 thin films and their application in selenization/sulfurization-free CuInS2 solar cells

2021 ◽  
Vol 26 ◽  
pp. 102050
Author(s):  
Mehdi Dehghani ◽  
Ershad Parvazian ◽  
Nastaran Alamgir Tehrani ◽  
Nima Taghavinia ◽  
Mahmoud Samadpour
Keyword(s):  
Thin Films ◽  
Solar Cells ◽  
Low Temperature ◽  
Temperature Growth ◽  
Low Temperature Growth ◽  
Cuins2 Thin Films

Strain-inhomogeneity effect on magnetization and low-temperature resistivity of epitaxial Fe(001) thin films

2004 ◽  
Vol 268 (1-2) ◽  
pp. 24-28 ◽  
Author(s):  
Z. Sefrioui ◽  
J.L. Menéndez ◽  
A. Cebollada ◽  
F. Briones ◽  
A. Hernando
Keyword(s):  
Thin Films ◽  
Low Temperature ◽  
Strain Inhomogeneity ◽  
Temperature Resistivity
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