Strain relaxation by edge dislocations in GaAs/GaAlAs double heterostructures

It has been well established that, due to the termination of the bulk periodic potential at the surface, the forces acting on the surface atoms are no longer symmetrical but the surface atoms are displaced from their ideal lattice positions. Similarly, additional surface relaxation due to the loss of periodicity is expected to occur at the points where some kinds of bulk defects, like dislocations, intersect the surface. There are experimental indications that the rather more pronounced contrast observed in TEM at these intersection points may be contributed to by the additional stress relaxation.The REM technique is sensitive to crystal orientation and provides an ideal method of detecting the surface strain relaxation. The diffraction contrast effects arise from the changes of the angle between the incident beam and the local surface reciprocal lattice resulting from the strain field on the surface.

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TEM study of phosphorus-implanted pseudomorphic Si0.88Ge0.12 on Si(100)

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100138713 ◽

1995 ◽

Vol 53 ◽

pp. 468-469

Author(s):

N. David Theodore ◽

Donald Y.C Lie ◽

J. H. Song ◽

Peter Crozier

Keyword(s):

Integrated Circuits ◽

Heterojunction Bipolar Transistors ◽

Integrated Circuit ◽

High Speed ◽

Room Temperature ◽

Strain Relaxation ◽

Bipolar Transistors ◽

Sige Hbt ◽

Integrated Circuit Manufacturing ◽

Microstructural Behavior

SiGe is being extensively investigated for use in heterojunction bipolar-transistors (HBT) and high-speed integrated circuits. The material offers adjustable bandgaps, improved carrier mobilities over Si homostructures, and compatibility with Si-based integrated-circuit manufacturing. SiGe HBT performance can be improved by increasing the base-doping or by widening the base link-region by ion implantation. A problem that arises however is that implantation can enhance strain-relaxation of SiGe/Si.Furthermore, once misfit or threading dislocations result, the defects can give rise to recombination-generation in depletion regions of semiconductor devices. It is of relevance therefore to study the damage and anneal behavior of implanted SiGe layers. The present study investigates the microstructural behavior of phosphorus implanted pseudomorphic metastable Si0.88Ge0.12 films on silicon, exposed to various anneals.Metastable pseudomorphic Si0.88Ge0.12 films were grown ~265 nm thick on a silicon wafer by molecular-beam epitaxy. Pieces of this wafer were then implanted at room temperature with 100 keV phosphorus ions to a dose of 1.5×1015 cm-2.

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TEM study of very thin InGaAsP layers grown by liquid-phase epitaxy

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100176496 ◽

1990 ◽

Vol 48 (4) ◽

pp. 672-673

Author(s):

N.A. Bert ◽

A.O. Kosogov

Keyword(s):

Liquid Phase ◽

Liquid Phase Epitaxy ◽

Chemical Vapor ◽

Growth Conditions ◽

Dark Field ◽

Organic Chemical ◽

Simple Liquid ◽

Cross Sectional ◽

Conventional Procedure ◽

Double Heterostructures

The very thin (<100 Å) InGaAsP layers were grown not only by molecular beam epitaxy and metal-organic chemical vapor deposition but recently also by simple liquid phase epitaxy (LPE) technique. Characterization of their thickness, interfase abruptness and lattice defects is important and requires TEM methods to be used.The samples were InGaAsP/InGaP double heterostructures grown on (111)A GaAs substrate. The exact growth conditions are described in Ref.1. The salient points are that the quarternary layers were being grown at 750°C during a fast movement of substrate and a convection caused in the melt by that movement was eliminated. TEM cross-section specimens were prepared by means of conventional procedure. The studies were conducted in EM 420T and JEM 4000EX instruments.The (200) dark-field cross-sectional imaging is the most appropriate TEM technique to distinguish between individual layers in 111-v semiconductor heterostructures.

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THE UTILITY OF 2D ELASTIC SCREW AND EDGE DISLOCATIONS FOR MODELING CRUSTAL DEFORMATION ASSOCIATED WITH SHEAR ZONES

10.1130/abs/2017am-302524 ◽

2017 ◽

Author(s):

Phillip K. Mcfarland ◽

◽

Richard A. Bennett

Keyword(s):

Crustal Deformation ◽

Shear Zones ◽

Edge Dislocations

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Elimination of emitter edge dislocations in silicon planar n-p-n transistors

Electronics Letters ◽

10.1049/el:19800598 ◽

1980 ◽

Vol 16 (22) ◽

pp. 842 ◽

Cited By ~ 4

Author(s):

N.D. Stojadinović ◽

R.S. Popović

Keyword(s):

Edge Dislocations

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Comparison of phase modulation of GaAs/AlGaAs double heterostructures

Electronics Letters ◽

10.1049/el:19870960 ◽

1987 ◽

Vol 23 (25) ◽

pp. 1391 ◽

Cited By ~ 10

Author(s):

J. Faist ◽

F.K. Reinhart ◽

D. Martin

Keyword(s):

Phase Modulation ◽

Double Heterostructures

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Strain Relaxation and In-Situ Observation of Voiding in Passivated Aluminum Alloy Lines.

MRS Proceedings ◽

10.1557/proc-308-249 ◽

1993 ◽

Vol 308 ◽

Cited By ~ 3

Author(s):

Paul R. Besser ◽

Thomas N. Marieb ◽

John C. Bravman

Keyword(s):

Strain Relaxation ◽

Grazing Incidence ◽

Scanning Transmission Electron Microscope ◽

In Situ Observation ◽

X Ray ◽

Scanning Transmission ◽

Length Width ◽

Measured Strain ◽

Ray Geometry

ABSTRACTStrain relaxation in passivated Al-0.5% Cu lines was measured using X-ray diffraction coupled with in-situ observation of the formation and growth of stress induced voids. Samples of 1 μm thick Al-0.5% Cu lines passivated with Si3N4 were heated to 380ºC, then cooled and held at 150ºC. During the test, principal strains along the length, width, and height of the line were determined using a grazing incidence x-ray geometry. From these measurements the hydrostatic strain in the metal was calculated and strain relaxation was observed. The thermal cycle was duplicated in a high voltage scanning transmission electron microscope equipped with a backscattered electron detector. The 1.25 μm wide lines were seen to have initial stress voids. Upon heating these voids reduced in size until no longer observable. Once the samples were cooled to 150ºC, voids reappeared and grew. The measured strain relaxation is discussed in terms of void and θ-phase (Al2Cu) formation.

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