Luminescence of GaAs/(Al,Ga)As superlattices grown on Si substrates, containing a high density of threading dislocations: Strong effect of the superlattice period

1988 ◽  
Vol 64 (12) ◽  
pp. 6810-6814 ◽  
Author(s):  
T. Y. Liu ◽  
P. M. Petroff ◽  
H. Kroemer
Keyword(s):  
High Density ◽  
Threading Dislocations ◽  
Si Substrates ◽  
Superlattice Period

Anisotropy of interfacial defects in the initial stage of MOVPE GaAs growth On Si

1990 ◽  
Vol 48 (4) ◽  
pp. 592-593
Author(s):  
C. Vannuffel ◽  
C. Schiller ◽  
J. P. Chevalier
Keyword(s):  
Early Stage ◽  
Threading Dislocations ◽  
Mbe Growth ◽  
Detailed Mechanism ◽  
Si Substrates ◽  
Initial Stage ◽  
Interfacial Defects ◽  
Interfacial Dislocations ◽  
Step Growth ◽  
Essential Problem

Recently, interest has focused on the epitaxy of GaAs on Si as a promising material for electronic applications, potentially for integration of optoelectronic devices on silicon wafers. The essential problem concerns the 4% misfit between the two materials, and this must be accommodated by a network of interfacial dislocations with the lowest number of threading dislocations. It is thus important to understand the detailed mechanism of the formation of this network, in order to eventually reduce the dislocation density at the top of the layers.MOVPE growth is carried out on slightly misoriented, (3.5°) from (001) towards , Si substrates. Here we report on the effect of this misorientation on the interfacial defects, at a very early stage of growth. Only the first stage, of the well-known two step growth process, is thus considered. Previously, we showed that full substrate coverage occured for GaAs thicknesses of 5 nm in contrast to MBE growth, where substantially greater thicknesses are required.

Defect Reduction in GaAs Epilayers on Si Substrates Using Strained Layer Superlattices

1987 ◽  
Vol 91 ◽  
Author(s):  
N. El-Masry ◽  
N. Hamaguchi ◽  
J.C.L. Tarn ◽  
N. Karam ◽  
T.P. Humphreys ◽  
...  
Keyword(s):  
Thermal Annealing ◽  
Rapid Thermal Annealing ◽  
Buffer Layers ◽  
Threading Dislocations ◽  
Defect Reduction ◽  
Strained Layer ◽  
Si Substrates ◽  
Density Of Dislocations ◽  
Strained Layer Superlattice ◽  
Strained Layer Superlattices

ABSTRACTInxGa11-xAs-GaAsl-yPy strained layer superlattice buffer layers have been used to reduce threading dislocations in GaAs grown on Si substrates. However, for an initially high density of dislocations, the strained layer superlattice is not an effective filtering system. Consequently, the emergence of dislocations from the SLS propagate upwards into the GaAs epilayer. However, by employing thermal annealing or rapid thermal annealing, the number of dislocation impinging on the SLS can be significantly reduced. Indeed, this treatment greatly enhances the efficiency and usefulness of the SLS in reducing the number of threading dislocations.

Observation of GaAs/Si Epitaxial Interfaces by Atomic Resolution Electron Microscopy

1986 ◽  
Vol 67 ◽  
Author(s):  
N. Otsuka ◽  
C. Choi ◽  
Y. Nakamura ◽  
S. Nagakura ◽  
R. Fischer ◽  
...  
Keyword(s):  
Substrate Surface ◽  
High Vacuum ◽  
Ultra High Vacuum ◽  
Threading Dislocations ◽  
Misfit Dislocations ◽  
Si Substrates ◽  
Voltage Electron ◽  
Resolution Electron ◽  
Gaas Films ◽  
Substrate Surfaces

ABSTRACTRecent studies have shown that high quality GaAs films can be grown by MBE on Si substrates whose surfaces are slightly tilted from the (100) plane. In order to investigate the effect of the tilting of substrate surfaces on the formation of threading dislocations, the GaAs/Si epitaxial interfaces have been observed with a 1 MB ultra-high vacuum, high voltage electron microscope. Two types of misfit dislocations, one with Burgers vectors parallel to the interface and the other with Burgers vectors inclined from the interface, were found in these epitaxial interfaces. The observation of crosssectional samples perpendicular to each other has shown that the tilting of the substrate surface directly influences the generation of these two types of misfit dislocations. The mechanism of the reduction of threading dislocations by the tilting of the substrate surface is discussed based on these observations.

Threading Dislocation Density Reduction in GaN/Sapphire Heterostructures.

1999 ◽  
Vol 595 ◽  
Author(s):  
A. Kvit ◽  
A. K. Sharma ◽  
J. Narayan
Keyword(s):  
Basal Plane ◽  
Stacking Faults ◽  
High Density ◽  
Thin Layers ◽  
Interfacial Region ◽  
Threading Dislocation ◽  
Threading Dislocations ◽  
Misfit Dislocations ◽  
Plan View ◽  
Partial Dislocations

AbstractLarge lattice mismatch between GaN and α-Al2O3 (15%) leads to the possibility of high threading dislocation densities in the nitride layers grown on sapphire. This investigation focused on defect reduction in GaN epitaxial thin layer was investigated as a function of processing variables. The microstructure changes from threading dislocations normal to the basal plane to stacking faults in the basal plane. The plan-view TEM and the corresponding selected-area diffraction patterns show that the film is single crystal and is aligned with a fixed epitaxial orientation to the substrate. The epitaxial relationship was found to be (0001)GaN∥(0001)Sap and [01-10]GaN∥[-12-10]Sap. This is equivalent to a 30° rotation in the basal (0001) plane. The film is found to contain a high density of stacking faults with average spacing 15 nm terminated by partial dislocations. The density of partial dislocations was estimated from plan-view TEM image to be 7×109 cm−2. The cross-section image of GaN film shows the density of stacking faults is highest in the vicinity of the interface and decreases markedly near the top of the layer. Inverted domain boundaries, which are almost perpendicular to the film surface, are also visible. The concentration of threading dislocation is relatively low (∼;2×108 cm−2), compared to misfit dislocations. The average distance between misfit dislocations was found to be 22 Å. Contrast modulations due to the strain near misfit dislocations are seen in high-resolution cross-sectional TCM micrograph of GaN/α-Al2O3 interface. This interface is sharp and does not contain any transitional layer. The interfacial region has a high density of Shockley and Frank partial dislocations. Mechanism of accommodation of tensile, sequence and tilt disorder through partial dislocation generation is discussed. In order to achieve low concentration of threading dislocations we need to establish favorable conditions for some stacking disorder in thin layers above the film-substrate interface region.

Reduction of threading dislocations by InGaAs interlayer in GaAs layers grown on Si substrates

1998 ◽  
Vol 73 (20) ◽  
pp. 2917-2919 ◽  
Author(s):  
Y. Takano ◽  
M. Hisaka ◽  
N. Fujii ◽  
K. Suzuki ◽  
K. Kuwahara ◽  
...  
Keyword(s):  
Threading Dislocations ◽  
Si Substrates

Threading dislocations in GaAs epitaxial layers on various thickness Ge buffers on 300 mm Si substrates

2016 ◽  
Vol 453 ◽  
pp. 180-187 ◽  
Author(s):  
Y. Bogumilowicz ◽  
J.M. Hartmann ◽  
N. Rochat ◽  
A. Salaun ◽  
M. Martin ◽  
...  
Keyword(s):  
Epitaxial Layers ◽  
Threading Dislocations ◽  
Si Substrates

scholarly journals Evolution of Threading Dislocations in GaN Films Grown on (111) Si Substrates with Various Buffer Layers

2006 ◽  
Vol 12 (S02) ◽  
pp. 906-907
Author(s):  
X Weng ◽  
J Acord ◽  
A Jain ◽  
S Raghavan ◽  
J Redwing ◽  
...  
Keyword(s):  
Buffer Layers ◽  
Threading Dislocations ◽  
Si Substrates

Extended abstract of a paper presented at Microscopy and Microanalysis 2006 in Chicago, Illinois, USA, July 30 – August 3, 2006

Preferential crystal growth of germanium by solid phase crystallization

2014 ◽  
Vol 92 (7/8) ◽  
pp. 576-581 ◽  
Author(s):  
Mikuri Kanai ◽  
Yuji Kojima ◽  
Masao Isomura
Keyword(s):  
Crystalline Silicon ◽  
Solid Phase ◽  
Electron Beam Evaporation ◽  
High Density ◽  
Solid Phase Crystallization ◽  
Air Exposure ◽  
Preferential Growth ◽  
Practical Applications ◽  
Si Substrates ◽  
P Type

We have investigated the preparation of crystalline germanium films by the solid phase crystallization (SPC) of amorphous germanium (a-Ge) precursor on single crystalline silicon substrates. The a-Ge precursor easily incorporates the impurities from the surface exposed to the air, and the impurities affect the crystallinity after the SPC. In the a-Ge precursor prepared by Knudsen-cell evaporation, the preferential crystalline growth following the Si substrates is disturbed by the high density of impurities and the random crystalline structures are formed. The a-Ge precursors prepared by electron beam evaporation have high impurity concentrations only near the surface because the impurity diffusion is slow because of the relatively high density. The preferential growth is successfully obtained in a-Ge precursor prepared on n-type Si substrates, although the random crystallization is slightly observed on p-type Si substrates. By sufficiently reducing the impurity concentrations by avoiding the air exposure, the preferential growth can be promoted on p-type Si substrates. The impurity incorporation because of the air exposure is sufficiently reduced for the preferential growth by covering a-Ge with a-Si blocking layers. This method is effective for future practical applications of SPC Ge films.

High-density protein patterning through selective plasma-induced fluorocarbon deposition on Si substrates

2009 ◽  
Vol 24 (10) ◽  
pp. 2979-2984 ◽  
Author(s):  
Pinelopi Bayiati ◽  
Antonia Malainou ◽  
Evrimahos Matrozos ◽  
Angeliki Tserepi ◽  
Panagiota S. Petrou ◽  
...  
Keyword(s):  
High Density ◽  
Protein Patterning ◽  
Si Substrates
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