Strain relaxation and defect reduction in InxGa1−xAs/GaAs by lateral oxidation of an underlying AlGaAs layer

The lack of high-quality native oxides on the III-V compounds has hindered the development of III-V integrated circuits and optoelectronic technology. Recently it was shown that stable oxides can be formed in the III-V compounds rich in Al, such as AlxGa1-x As similarly as it was done in Si technology by the reaction of AlxGa1-x As with H2O vapor (in N2 carrier gas) at elevated temperatures (∼400−450°C). The high quality of these oxides was attributed to the formation of stable AlO(OH) and Al2O3 compounds. However, this conclusion was not definitive, since several Al rich compounds were proposed as well. In addition, it was never clarified whether the excess As created in this process has any role in the stabilization of these oxides, in reducing leakage current or in impurity diffusion. Moreover there is concern as to the quality of the oxide/GaAs interfaces created by lateral oxidation of an intermediate AlGaAs layer.

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Lattice Engineering Using Lateral Oxidation of Alas: an Approach to Generate Substrates With New Lattice Constants

MRS Proceedings ◽

10.1557/proc-535-21 ◽

1998 ◽

Vol 535 ◽

Author(s):

P.M. Chavarkar ◽

L. Zhao ◽

S. Keller ◽

K.A. Black ◽

E. Hu ◽

...

Keyword(s):

Strain Relaxation ◽

Local Strain ◽

Epitaxial Layers ◽

Threading Dislocation ◽

Misfit Dislocations ◽

Reactive Material ◽

New Approach ◽

Lattice Constants ◽

Lateral Oxidation ◽

Threading Dislocation Density

AbstractWe demonstrate a new approach to the growth of dislocation free lattice-mismatched materials on GaAs substrates using Al2O3 interlayers obtained by lateral oxidation of AlAs. This is achieved by generating relaxed low threading dislocation density InGaAs templates which are mechanically supported but epitaxially decoupled from the host GaAs substrate. This process uses the phenomena of relaxation of strained coherent hypercritical thickness (h > hcritical,) layer in direct contact with an oxidizing Al-containing semiconductor (i.e. AlAs or AlGaAs). 5000 Å In0.11Ga0.89As layers were then grown on the In0.2 Ga0.8As/Al2O3/GaAs template which acts as a pseudo-substrate (lattice-engineered substrate). The epitaxial layers are partially relaxed and have extremely smooth surface morphology. Further TEM micrographs of these epitaxial layers show no misfit dislocations or related localized strain fields at the In0.2Ga0.8As/Al2O3 interface. The absence of misfit dislocations or local strain contrast at the In0.2Ga0.8As/Al2O3 interface is attributed to both reactive material removal during the oxidation process and the porous nature of the oxide itself. We propose that the strain relaxation in In0.3Ga0.7As is enhanced due to the absence of misfit dislocations at the In0.2Ga0.8As/A12O3 interface.

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Influence of defect reduction and strain relaxation on carrier dynamics in InGaN-based light-emitting diodes on cone-shaped patterned sapphire substrates

Journal of Applied Physics ◽

10.1063/1.4803515 ◽

2013 ◽

Vol 113 (17) ◽

pp. 173512 ◽

Cited By ~ 12

Author(s):

Kyu-Seung Lee ◽

Isnaeni ◽

Yang-Seok Yoo ◽

Jae-Hoon Lee ◽

Yong-Chun Kim ◽

...

Keyword(s):

Light Emitting Diodes ◽

Strain Relaxation ◽

Carrier Dynamics ◽

Defect Reduction ◽

Light Emitting ◽

Sapphire Substrates ◽

Patterned Sapphire Substrates

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Block Copolymer Templating for Formation of Quantum Dots and Lattice Mismatched Semiconductor Structures

MRS Proceedings ◽

10.1557/proc-1258-q13-05 ◽

2010 ◽

Vol 1258 ◽

Author(s):

Smita Jha ◽

Chi-Chun Liu ◽

Joo Hyung Park ◽

Monika K. Wiedmann ◽

T S Kuan ◽

...

Keyword(s):

Quantum Dots ◽

Block Copolymer ◽

Self Assembly ◽

Strain Relaxation ◽

Selective Area Growth ◽

Regular Array ◽

Defect Reduction ◽

Precise Control ◽

Semiconductor Structures ◽

Selective Area

AbstractTemplated growth for the fabrication of semiconductor nanostructures such as quantum dots and lattice-mismatched structures has been employed in this study. Self assembly of block copolymers (BCP) has been exploited to create a regular array of nanoscale patterns on a substrate to generate the growth template. These patterned templates were used for the selective area growth of pseudomorphic quantum dots, allowing for precise control over the dot size and spatial distribution. Strain relaxation in lattice-mismatched structures grown past the pseudomorphic limit was also studied. Analysis of the grown structures suggests that this approach using block copolymer templating followed by selective growth can be used for defect reduction in lattice-mismatched materials.

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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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Defect reduction in oxygen implanted silicon-on-insulator material during high-temperature annealing

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100154998 ◽

1989 ◽

Vol 47 ◽

pp. 604-605

Author(s):

P. Roitman ◽

B. Cordts ◽

S. Visitserngtrakul ◽

S.J. Krause

Keyword(s):

High Temperature ◽

Annealing Temperature ◽

Silicon On Insulator ◽

High Dose ◽

High Temperature Annealing ◽

High Current ◽

Defect Reduction ◽

Annealing Step ◽

Multiple Cycle ◽

Defect Densities

Synthesis of a thin, buried dielectric layer to form a silicon-on-insulator (SOI) material by high dose oxygen implantation (SIMOX – Separation by IMplanted Oxygen) is becoming an important technology due to the advent of high current (200 mA) oxygen implanters. Recently, reductions in defect densities from 109 cm−2 down to 107 cm−2 or less have been reported. They were achieved with a final high temperature annealing step (1300°C – 1400°C) in conjunction with: a) high temperature implantation or; b) channeling implantation or; c) multiple cycle implantation. However, the processes and conditions for reduction and elimination of precipitates and defects during high temperature annealing are not well understood. In this work we have studied the effect of annealing temperature on defect and precipitate reduction for SIMOX samples which were processed first with high temperature, high current implantation followed by high temperature annealing.

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Defect Reduction in Ring Blank Casting Through Design of Experiments

International Review of Mechanical Engineering (IREME) ◽

10.15866/ireme.v9i6.7627 ◽

2015 ◽

Vol 9 (6) ◽

pp. 536 ◽

Cited By ~ 1

Author(s):

P. Kannan ◽

K. Balasubramanian ◽

R. Vinayagamoorthy

Keyword(s):

Design Of Experiments ◽

Defect Reduction ◽

Ring Blank

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