Semiconductor Superlattices: Order and Disorder

1987 ◽  
Vol 93 ◽  
Author(s):  
R. Hull ◽  
J. E. Turner ◽  
A. Fischer-Colbrie ◽  
Alice E. Whitea ◽  
K. T. Short ◽  
...  
Keyword(s):  
Lattice Mismatch ◽  
Strain Relaxation ◽  
Multilayer Structures ◽  
Two Dimensional ◽  
Semiconductor Alloys ◽  
Dislocation Generation ◽  
Growth Interface ◽  
Order And Disorder ◽  
Metastable Structures ◽  
Si Ion Implantation

ABSTRACTWe review and discuss the main structural phenomena inherent in epitaxial multilayer semiconductor growth: lattice mismatch, misfit dislocation generation, two-dimensional vs. threedimensional growth, interface abruptness and planarity and the local atomic structure of semiconductor alloys. The prevalence of metastable structures, often a function of crystal growth temperature, is discussed. We also investigate the effect of Si ion implantation and subsequent rapid thermal annealing of AlGaAs/GaAs and InGaAs/GaAs multilayer structures, with reference to strain relaxation, layer planarity and enhanced Al, In and Si diffusion.

scholarly journals Strain relaxation via formation of cracks in compositionally modulated two-dimensional semiconductor alloys

2018 ◽  
Vol 2 (1) ◽  
Author(s):  
Hossein Taghinejad ◽  
Ali A. Eftekhar ◽  
Philip M. Campbell ◽  
Brian Beatty ◽  
Mohammad Taghinejad ◽  
...  
Keyword(s):  
Strain Relaxation ◽  
Two Dimensional ◽  
Semiconductor Alloys ◽  
Formation Of Cracks

Misfit Dislocation Nucleation and Interactions at GexSi1-x/Si Interfaces

1989 ◽  
Vol 160 ◽  
Author(s):  
D.D. Perovic ◽  
G.C. Weatherly ◽  
D.C. Houghton
Keyword(s):  
Misfit Dislocation ◽  
Dominant Role ◽  
Strain Relaxation ◽  
Dislocation Nucleation ◽  
Interfacial Dislocation ◽  
Dislocation Generation ◽  
Transmission Electron ◽  
Metastable Structures ◽  
Nucleation Mechanisms ◽  
Generation Mechanisms

AbstractIn the study of elastic strain relaxation in semiconductor heterostructures, a number of misfit dislocation generation mechanisms have been suggested to account for the high interfacial dislocation density observed in these almost defect-free crystals. Several MBE-grown GexSi1-x/Si heterostructures, both in the as-grown and annealed condition have been studied using transmission electron microscopy. The results indicate that some of the popular theories of dislocation generation are less important or not applicable based on both theoretical and experimental considerations. Specifically, it will be shown that: (i) heterogeneous sources play a dominant role in the nucleation mechanisms, (ii) the strain relaxation behaviour during MBE growth may be different from that observed in metastable structures annealed after growth and (iii) the Hagen-S trunk multiplication mechanism is inoperative under most conditions in this system.

Defects in β-SiC thin films grown on α-SiC substrates

1988 ◽  
Vol 46 ◽  
pp. 568-569
Author(s):  
Karren L. More
Keyword(s):  
Thin Films ◽  
Semiconductor Device ◽  
Lattice Mismatch ◽  
Chemical Vapor ◽  
Substrate Material ◽  
Growth Interface ◽  
Si Substrates ◽  
Thermal Expansion Coefficients ◽  
Device Applications ◽  
Expansion Coefficients

Beta-SiC is an ideal candidate material for use in semiconductor device applications. Currently, monocrystalline β-SiC thin films are epitaxially grown on {100} Si substrates by chemical vapor deposition (CVD). These films, however, contain a high density of defects such as stacking faults, microtwins, and antiphase boundaries (APBs) as a result of the 20% lattice mismatch across the growth interface and an 8% difference in thermal expansion coefficients between Si and SiC. An ideal substrate material for the growth of β-SiC is α-SiC. Unfortunately, high purity, bulk α-SiC single crystals are very difficult to grow. The major source of SiC suitable for use as a substrate material is the random growth of {0001} 6H α-SiC crystals in an Acheson furnace used to make SiC grit for abrasive applications. To prepare clean, atomically smooth surfaces, the substrates are oxidized at 1473 K in flowing 02 for 1.5 h which removes ∽50 nm of the as-grown surface. The natural {0001} surface can terminate as either a Si (0001) layer or as a C (0001) layer.

Development of Cross-Hatch Morphology During Growth of Lattice Mismatched Layers

2001 ◽  
Vol 673 ◽  
Author(s):  
A. Maxwell Andrews ◽  
J.S. Speck ◽  
A.E. Romanov ◽  
M. Bobeth ◽  
W. Pompe
Keyword(s):  
Misfit Dislocation ◽  
Film Growth ◽  
Strain Relaxation ◽  
Dislocation Generation ◽  
Force Microscopy ◽  
Step Flow ◽  
Atomic Force ◽  
Subsequent Step ◽  
Step Flow Growth ◽  
Lateral Scale

ABSTRACTAn approach is developed for understanding the cross-hatch morphology in lattice mismatched heteroepitaxial film growth. It is demonstrated that both strain relaxation associated with misfit dislocation formation and subsequent step elimination (e.g. by step-flow growth) are responsible for the appearance of nanoscopic surface height undulations (0.1-10 nm) on a mesoscopic (∼100 nm) lateral scale. The results of Monte Carlo simulations for dislocation- assisted strain relaxation and subsequent film growth predict the development of cross-hatch patterns with a characteristic surface undulation magnitude ∼50 Å in an approximately 70% strain relaxed In0.25Ga0.75As layers. The model is supported by atomic force microscopy (AFM) observations of cross-hatch morphology in the same composition samples grown well beyond the critical thickness for misfit dislocation generation.

MBE Growth and Characterization of SxGe1−x Multilayer Structures on Si (100) for Use as a Substrate for GaAs Heteroepitaxy

1991 ◽  
Vol 220 ◽  
Author(s):  
J. B. Posthill ◽  
D. P. Malta ◽  
R. Venkatasubramanian ◽  
P. R. Sharps ◽  
M. L. Timmons ◽  
...  
Keyword(s):  
Molecular Beam ◽  
Lattice Mismatch ◽  
Antiphase Domain ◽  
Multilayer Structures ◽  
Si Substrate ◽  
Mbe Growth ◽  
Etch Pit ◽  
Layer Structures ◽  
Domain Boundaries

ABSTRACTInvestigation has continued into the use of SixGe1−x multilayer structures (MLS) as a buffer layer between a Si substrate and a GaAs epitaxial layer in order to accommodate the 4.1% lattice mismatch. SixGe1−x 4-layer and 5-layer structures terminating in pure Ge have been grown using molecular beam epitaxy. Subsequent GaAs heteroepitaxy has allowed evaluation of these various GaAs/SixGe1−xMLS/Si (100) structures. Antiphase domain boundaries have been eliminated using vicinal Si (100) substrates tilted 6° off-axis toward [011], and the etch pit density in GaAs grown on a 5-layer SixGe1−x MLS on vicinal Si (lOO) was measured to be 106 cm−2.

scholarly journals Preparation, Structure and Properties of Two-dimensional Semiconductor Alloys

2015 ◽  
Vol 73 (9) ◽  
pp. 886 ◽  
Author(s):  
Xinsheng Wang ◽  
Liming Xie ◽  
Jin Zhang
Keyword(s):  
Two Dimensional ◽  
Structure And Properties ◽  
Semiconductor Alloys

Accurate Lattice Constant and Mismatch Measurements of SiC Heterostructures by X-Ray Multiple-Order Reflections

2002 ◽  
Vol 742 ◽  
Author(s):  
XianRong Huang ◽  
Michael Dudley ◽  
Philip G. Neudeck ◽  
J. Anthony Powell
Keyword(s):  
Lattice Mismatch ◽  
Strain Relaxation ◽  
Relaxation Mechanism ◽  
X Ray Diffraction ◽  
Crystalline Perfection ◽  
Coherent Interface ◽  
Rocking Curve ◽  
X Ray ◽  
Lattice Planes ◽  
Atomically Flat

ABSTRACTHigh-resolution X-ray diffraction (HRXRD) combined with other diffraction techniques is applied to characterize 3C SiC epilayers hoteroepitaxially grown on atomically flat mesas on 4H and 6H SiC substrates. Small-beam rocking curve scan and reciprocal mapping show extremely high crystalline perfection and homogeneity of the ideally grown 3C-SiC epilayers. Accurate lattice measurements based on X-ray multiple-order reflections reveal that: 1) no misorientation between the (0001) lattice planes across the 4H/3C or 6H/3C interface is detected, confirming the 2D nucleation mechanism of the 3C epilayer from a flat coherent interface; 2) in-plane substrate/epilayer lattice mismatch always exists, but the 3C epilayers do not correspond to a completely relaxed cubic structure, indicating that the epilayers are partially strained; 3) lattice mismatch varies for different regions, implying a complicated strain relaxation mechanism of 3C epilayers on various mesas.

Bandstructure Near Misfit Dislocations in Si Quantum Wells

1998 ◽  
Vol 4 (S2) ◽  
pp. 794-795
Author(s):  
P.E. Batson
Keyword(s):  
Quantum Wells ◽  
Conduction Band ◽  
Electron Mobility ◽  
Axial Strain ◽  
Strain Relaxation ◽  
Local Potential ◽  
Misfit Dislocations ◽  
High Electron ◽  
Strained Si ◽  
Growth Interface

High electron mobility structures have been built for several years now using strained silicon layers grown on SixGe(1-x) with x in the 25-40% range. In these structures, a thin layer of silicon is grown between layers of unstrained GeSi alloy. Matching of the two lattices in the plane of growth produces a bi-axial strain in the silicon, splitting the conduction band and providing light electron levels for enhanced mobility. If the silicon channel becomes too thick, strain relaxation can occur by injection of misfit dislocations at the growth interface between the silicon and GeSi alloy. The strain field of these dislocations then gives rise to a local potential variation that limits electron mobility in the strained Si channel. This study seeks to verify this mechanism by measuring the absolute conduction band shifts which track the local potential near the misfit dislocations.

CBED Investigations of Mesoscopic Semiconductor Structures

1999 ◽  
Vol 5 (S2) ◽  
pp. 208-209
Author(s):  
H. Lakner ◽  
F. Schulze-Kraasch ◽  
C. Mendorf ◽  
G. Brockt
Keyword(s):  
High Speed ◽  
Lattice Mismatch ◽  
Strain Relaxation ◽  
Local Strain ◽  
Tetragonal Distortion ◽  
Strained Layers ◽  
Spatially Resolved ◽  
Relaxation Effects ◽  
Convergent Beam ◽  
Induced Defects

Ternary and quaternary heterostructures from III-V-semiconductors get more and more importance in the fabrication of high-speed/high frequency devices in telecommunication systems. One of the key parameters for the performance of such devices is the crystalline quality and especially the amount of tetragonal distortion in strained layers on a nanometer scale. Strain can cause problems for the growth of such layers like relaxation induced defects, especially for the case of a high value of lattice mismatch. However, strain and the associated influence on the band structure can be used consciously for the design of tailor-made heterostructures (band gap engineering). Therefore, the spatially resolved investigation of local crystal properties (tetragonal distortion or strain and strain relaxation) is a key tool for the characterization of strained layers.Convergent beam electron diffraction (CBED) patterns and convergent beam imaging (CBIM) can be used to evaluate informations on the local crystalline structure. E.g. the position of the High Order Laue Zone (HOLZ) lines in the CBED patterns is sensitive to the local strain and therefore can be used to determine strain and relaxation effects in heterostructures quantitatively. But in practice the applicability of CBED is often limited by a lack of ultimate spatial resolution and/or of sensitivity.

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