Electronic Processes in Heterostructures, Strained-Layer Materials, and Laterally Patterned Structures.

1994 ◽  
Author(s):  
D. C. Tsui
Keyword(s):  
Strained Layer ◽  
Patterned Structures

In situ TEM measurements of the electrical properties of interface dislocations

1992 ◽  
Vol 50 (2) ◽  
pp. 1338-1339
Author(s):  
F. M. Ross ◽  
R. Hull ◽  
D. Bahnck ◽  
J. C. Bean ◽  
L. J. Peticolas ◽  
...  
Keyword(s):  
Electrical Properties ◽  
Electronic Device ◽  
In Situ Tem ◽  
Device Performance ◽  
Misfit Dislocations ◽  
Electrical Characteristics ◽  
Strained Layer ◽  
Transmission Electron ◽  
Interfacial Dislocations

We describe an investigation of the electrical properties of interfacial dislocations in strained layer heterostructures. We have been measuring both the structural and electrical characteristics of strained layer p-n junction diodes simultaneously in a transmission electron microscope, enabling us to correlate changes in the electrical characteristics of a device with the formation of dislocations.The presence of dislocations within an electronic device is known to degrade the device performance. This degradation is of increasing significance in the design and processing of novel strained layer devices which may require layer thicknesses above the critical thickness (hc), where it is energetically favourable for the layers to relax by the formation of misfit dislocations at the strained interfaces. In order to quantify how device performance is affected when relaxation occurs we have therefore been investigating the electrical properties of dislocations at the p-n junction in Si/GeSi diodes.

The limits of strain and lattice parameter measurements by CBED

1989 ◽  
Vol 47 ◽  
pp. 518-519
Author(s):  
Hamish L. Fraser
Keyword(s):  
Electron Beam ◽  
Mirror Symmetry ◽  
Local Symmetry ◽  
Lattice Parameter ◽  
Growth Direction ◽  
Surface Relaxation ◽  
Strained Layer ◽  
Axis Parallel ◽  
Local Lattice ◽  
Strained Layer Superlattice

The topic of strain and lattice parameter measurements using CBED is discussed by reference to several examples. In this paper, only one of these examples is referenced because of the limitation of length. In this technique, scattering in the higher order Laue zones is used to determine local lattice parameters. Work (e.g. 1) has concentrated on a model strained-layer superlattice, namely Si/Gex-Si1-x. In bulk samples, the strain is expected to be tetragonal in nature with the unique axis parallel to [100], the growth direction. When CBED patterns are recorded from the alloy epi-layers, the symmetries exhibited by the patterns are not tetragonal, but are in fact distorted from this to lower symmetries. The spatial variation of the distortion close to a strained-layer interface has been assessed. This is most readily noted by consideration of Fig. 1(a-c), which show enlargements of CBED patterns for various locations and compositions of Ge. Thus, Fig. 1(a) was obtained with the electron beam positioned in the center of a 5Ge epilayer and the distortion is consistent with an orthorhombic distortion. When the beam is situated at about 150 nm from the interface, the same part of the CBED pattern is shown in Fig. 1(b); clearly, the symmetry exhibited by the mirror planes in Fig. 1 is broken. Finally, when the electron beam is positioned in the center of a 10Ge epilayer, the CBED pattern yields the result shown in Fig. 1(c). In this case, the break in the mirror symmetry is independent of distance form the heterointerface, as might be expected from the increase in the mismatch between 5 and 10%Ge, i.e. 0.2 to 0.4%, respectively. From computer simulation, Fig.2, the apparent monocline distortion corresponding to the 5Ge epilayer is quantified as a100 = 0.5443 nm, a010 = 0.5429 nm and a001 = 0.5440 nm (all ± 0.0001 nm), and α = β = 90°, γ = 89.96 ± 0.02°. These local symmetry changes are most likely due to surface relaxation phenomena.

Si-Ge STRAINED LAYER SUPERLATTICES

1987 ◽  
Vol 48 (C5) ◽  
pp. C5-321-C5-327 ◽  
Author(s):  
H. BRUGGER ◽  
G. ABSTREITER
Keyword(s):  
Strained Layer ◽  
Strained Layer Superlattices

Hybrid Micro-Optical Sensors via Sol-Gel Soft Lithography

2000 ◽  
Vol 628 ◽  
Author(s):  
Mark A. Clarner ◽  
Michael J. Lochhead
Keyword(s):  
Optical Sensors ◽  
Soft Lithography ◽  
Sol Gel ◽  
Silica Gels ◽  
Ph Sensing ◽  
Ambient Conditions ◽  
Sensor Applications ◽  
Patterned Structures ◽  
Biological Functionality ◽  
Indicator Dyes

ABSTRACTOrganically modified silica gels and dye-doped silica gels have been patterned into micrometer-scale structures on a substrate using micro molding in capillaries (MIMIC). This approach is from a class of elastomeric stamping and molding techniques collectively known as soft lithography. Soft lithography and sol-gel processing share attractive features in that they are relatively benign processes performed at ambient conditions, which makes both techniques compatible with a wide variety of organic molecules, molecular assemblies, and biomolecules. The combination of sol-gel and soft lithography, therefore, holds enormous promise as a tool for microfabrication of materials with optical, chemical, or biological functionality that are not readily patterned with conventional methods. This paper describes our investigation of micro-patterned organic-inorganic hybrid materials containing indicator dyes for microfluidic sensor applications. Reversible colorimetric pH sensing via entrapped reagents is demonstrated in a prototype microfluidic sensor element. Patterned structures range from one to tens of micrometers in cross-section and are up to centimeters in length. Fundamental chemical processing issues associated with mold filling, cracking and sensor stability are discussed.

Hybrid Valence Bands in Strained-Layer Heterostructures grown on Relaxed SiGe Virtual Substrates

2003 ◽  
Vol 765 ◽  
Author(s):  
Minjoo L. Lee ◽  
Eugene A. Fitzgerald
Keyword(s):  
Strained Silicon ◽  
Strained Layer ◽  
Dual Channel ◽  
Enhanced Mobility ◽  
Valence Bands ◽  
Almost All

AbstractThe use of alternative channel materials such as germanium [1,2] and strained silicon (ε-Si) [3-5] is increasingly being considered as a method for improving the performance of MOSFETs. While ε-Si grown on relaxed Si1-x Gex is drawing closer to widespread commercialization, it is currently believed that almost all of the performance benefit in CMOS implementations will derive from the enhanced mobility of the n -MOSFET [5]. In this paper, we demonstrate that ε-Si p -MOSFETs can be engineered to exhibit mobility enhancements that increase or remain constant as a function of inversion density. We have also designed and fabricated ε-Si / ε-Ge dual-channel p -MOSFETs exhibiting mobility enhancements of 10 times. These p -MOSFETs can be integrated on the same wafers as ε-Si n -MOSFETs, making symmetric-mobility CMOS possible.

Erratum: Monolithic integration of an InGaAs/GaAs/AlGaAs strained layer SQW LED and GaAs MESFET using epitaxial lift-off

1990 ◽  
Vol 26 (16) ◽  
pp. 1324
Author(s):  
I. Pollentier ◽  
L. Buydens ◽  
A. Ackaert ◽  
P. Demeester ◽  
P. van Daele ◽  
...  
Keyword(s):  
Monolithic Integration ◽  
Strained Layer ◽  
Gaas Mesfet ◽  
Lift Off

scholarly journals Improved Copper–Epoxy Adhesion by Laser Micro- and Nano-Structuring of Copper Surface for Thermal Applications

Polymers ◽  
2021 ◽  
Vol 13 (11) ◽  
pp. 1721
Author(s):  
Mario Mora ◽  
Hippolyte Amaveda ◽  
Luis Porta-Velilla ◽  
Germán F. de la Fuente ◽  
Elena Martínez ◽  
...  
Keyword(s):  
Thermal Conductivity ◽  
Bonding Strength ◽  
Copper Surface ◽  
Heat Sinks ◽  
Electrical Insulation ◽  
Cryogenic Temperatures ◽  
Shear Tests ◽  
Patterned Structures ◽  
Different Temperatures ◽  
Mechanical Tensile

The objective of this work is the enhancement of metal-to-metal bonding to provide high thermal conductivity together with electrical insulation, to be used as heat sinks at room and cryogenic temperatures. High thermal conductive metal (copper) and epoxy resin (Stycast 2850FT) were used in this study, with the latter also providing the required electrical insulation. The copper surface was irradiated with laser to induce micro- and nano-patterned structures that result in an improvement of the adhesion between the epoxy and the copper. Thus, copper-to-copper bonding strength was characterized by means of mechanical tensile shear tests. The effect of the laser processing on the thermal conductivity properties of the Cu/epoxy/Cu joint at different temperatures, from 10 to 300 K, is also reported. Using adequate laser parameters, it is possible to obtain high bonding strength values limited by cohesive epoxy fracture, together with good thermal conductivity at ambient and cryogenic temperatures.

Planar channeling in GaAs/InxGa1−xAs/GaAs strained‐layer structures

1989 ◽  
Vol 65 (4) ◽  
pp. 1510-1515 ◽  
Author(s):  
J. L. E. Stevens ◽  
B. J. Robinson ◽  
J. A. Davies ◽  
D. A. Thompson ◽  
T. E. Jackman
Keyword(s):  
Planar Channeling ◽  
Strained Layer ◽  
Layer Structures

nBn structure based on InAs∕GaSb type-II strained layer superlattices

2007 ◽  
Vol 91 (4) ◽  
pp. 043514 ◽  
Author(s):  
J. B. Rodriguez ◽  
E. Plis ◽  
G. Bishop ◽  
Y. D. Sharma ◽  
H. Kim ◽  
...  
Keyword(s):  
Type Ii ◽  
Strained Layer ◽  
Strained Layer Superlattices
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