Strain-relaxation mechanisms of SiGe layers formed by two-step growth on Si(0 0 1) substrates

2004 ◽  
Vol 224 (1-4) ◽  
pp. 104-107 ◽  
Author(s):  
T Egawa ◽  
A Sakai ◽  
T Yamamoto ◽  
N Taoka ◽  
O Nakatsuka ◽  
...  
Keyword(s):  
Strain Relaxation ◽  
Step Growth

Strain Relaxation and Dislocation Confinement in Epitaxial SrTiO3 by Two-Step Growth Technique and the Resulting Dielectric Response

2005 ◽  
Vol 902 ◽  
Author(s):  
Tomoaki Yamada ◽  
Vladimir O. Sherman ◽  
Alexander K. Tagantsev ◽  
Dong Su ◽  
Paul Muralt ◽  
...  
Keyword(s):  
Lattice Mismatch ◽  
Strain Relaxation ◽  
Effective Strain ◽  
Microwave Dielectric Properties ◽  
Threading Dislocation ◽  
Misfit Dislocations ◽  
Initial Growth ◽  
Growth Step ◽  
Growth Technique ◽  
Step Growth

AbstractA two-step growth technique was used to achieve effective strain relaxation and dislocation confinement of epitaxial SrTiO3(STO) films and through this to improve their microwave dielectric properties. The crystallization of a very thin quasi-amorphous STO layer deposited at a low temperature in the initial growth step enhanced the strain relaxation from the lattice mismatch at the expense of the formation of high density of misfit dislocations. By varying the thickness of the first layer, different strain states of the films were systematically achieved while keeping the total film thickness unchanged. This allowed the study of the effect of strain on permittivity, and showed good agreement with theoretical predictions. Further more, the two-step growth technique suppressed significantly the threading dislocation density in the film, the dislocations being confined to the first layer. This in turn caused reduction in the extrinsic dielectric loss at microwave frequency. The loss reduction was analyzed and explained based on a dielectric composite model.

Strain relaxation of epitaxial SrTiO3 thin films on LaAlO3 by two-step growth technique

2005 ◽  
Vol 86 (14) ◽  
pp. 142904 ◽  
Author(s):  
Tomoaki Yamada ◽  
Konstantin F. Astafiev ◽  
Vladimir O. Sherman ◽  
Alexander K. Tagantsev ◽  
Paul Muralt ◽  
...  
Keyword(s):  
Thin Films ◽  
Strain Relaxation ◽  
Growth Technique ◽  
Step Growth

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

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.

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.

Polymer Chemistry

2004 ◽  
Keyword(s):  
Conducting Polymers ◽  
Liquid Crystalline ◽  
Polymer Chemistry ◽  
Chain Growth ◽  
Crystalline Polymers ◽  
Wide Range ◽  
Cyclic Oligomers ◽  
Step Growth

Polymer Chemistry: A Practical Approach in Chemistry has been designed for both chemists working in and new to the area of polymer synthesis. It contains detailed instructions for preparation of a wide-range of polymers by a wide variety of different techniques, and describes how this synthetic methodology can be applied to the development of new materials. It includes details of well-established techniques, e.g. chain-growth or step-growth processes together with more up-to-date examples using methods such as atom-transfer radical polymerization. Less well-known procedures are also included, e.g. electrochemical synthesis of conducting polymers and the preparation of liquid crystalline elastomers with highly ordered structures. Other topics covered include general polymerization methodology, controlled/"living" polymerization methods, the formation of cyclic oligomers during step-growth polymerization, the synthesis of conducting polymers based on heterocyclic compounds, dendrimers, the preparation of imprinted polymers and liquid crystalline polymers. The main bulk of the text is preceded by an introductory chapter detailing some of the techniques available to the scientist for the characterization of polymers, both in terms of their chemical composition and in terms of their properties as materials. The book is intended not only for the specialist in polymer chemistry, but also for the organic chemist with little experience who requires a practical introduction to the field.

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

1993 ◽  
Vol 308 ◽  
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.

Strain Relaxation in (CdMg)Te Layers Grown by Molecular Beam Epitaxy

1995 ◽  
Vol 182-184 ◽  
pp. 255-258
Author(s):  
H. Heinke ◽  
Franz Dieter Fischer ◽  
A. Waag ◽  
T. Litz ◽  
M. Korn ◽  
...  
Keyword(s):  
Molecular Beam Epitaxy ◽  
Molecular Beam ◽  
Strain Relaxation

One step “growth to spinning” of biaxially multilayered CNT web electrode for long cycling Li-O2 batteries

Carbon ◽  
2021 ◽  
Author(s):  
Young Shik Cho ◽  
Hyunjin Kim ◽  
Minhoo Byeon ◽  
Yeonsu Jung ◽  
DongJoon Lee ◽  
...  
Keyword(s):  
One Step ◽  
Step Growth
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