Si1−xGex Island Formation by Post-Growth Anneal on Supercritical Layers Grown by RPCVD

2000 ◽  
Vol 618 ◽  
Author(s):  
K. Grimm ◽  
L. Vescan ◽  
L.K. Nanver ◽  
C.C.G. Visser ◽  
H. Lüthl
Keyword(s):  
Epitaxial Growth ◽  
Low Temperatures ◽  
Critical Thickness ◽  
Plastic Relaxation ◽  
Size Distributions ◽  
Uniform Size ◽  
High Hydrogen ◽  
Strong Emission ◽  
Order Of Magnitude ◽  
Degree Of Control

ABSTRACTSiGe island layers have been created by post growth anneal on supercritical layers grown at low temperatures (500°C) and high hydrogen pressures (40 Torr). The epitaxial growth has been performed in a commercially available single wafer RPCVD reactor using SiH2Cl2 and GeH4 as precursor gasses. SiGe layers grown under these conditions exceed the critical thickness for the onset of elastic relaxation reported for lower hydrogen pressures as well as the critical thickness for plastic relaxation by more than one order of magnitude. A subsequent anneal step is used to form the islands. This procedure allows some degree of control in the formation of SiGe islands. High island densities and uniform size distributions were achieved. Photoluminescence as well as electroluminescence measurements of these layers show strong emission from SiGe.

Equilibrium size distributions of clusters during strained epitaxial growth

1999 ◽  
Vol 67 (1-2) ◽  
pp. 31-38 ◽  
Author(s):  
G Medeiros-Ribeiro ◽  
T.I Kamins ◽  
D.A.A Ohlberg ◽  
R.Stanley Williams
Keyword(s):  
Epitaxial Growth ◽  
Size Distributions ◽  
Equilibrium Size

Ion Induced Grain Growth in Pd

1991 ◽  
Vol 235 ◽  
Author(s):  
D. A. Lilienfeld ◽  
P. Bøorgesen ◽  
P. Meyer
Keyword(s):  
Thin Films ◽  
Grain Size ◽  
Grain Growth ◽  
Low Temperatures ◽  
Nanocrystalline Materials ◽  
Ion Irradiation ◽  
Size Distributions ◽  
Careful Choice ◽  
Average Grain Size

ABSTRACTIon irradiation induced grain growth size distributions in Pd are examined at low temperatures. Two features are observed: 1) A majority of the grains saturate in size. 2) Some grains achieve sizes much larger than the average grain size and continue to grow with ion dose. However, by careful choice of ion mass and ion dose, it is possible to produce a sample possessing a monomodal grain size. This process will have applications in producing thin films of nanocrystalline materials.

scholarly journals Nanoparticle formation by ozonolysis of inducible plant volatiles

2005 ◽  
Vol 5 (6) ◽  
pp. 1489-1495 ◽  
Author(s):  
J. Joutsensaari ◽  
M. Loivamäki ◽  
T. Vuorinen ◽  
P. Miettinen ◽  
A.-M. Nerg ◽  
...  
Keyword(s):  
Laboratory Experiments ◽  
Oxidation Products ◽  
Size Distributions ◽  
Aerosol Formation ◽  
Particle Size Distributions ◽  
Organic Species ◽  
Atmospheric Nucleation ◽  
White Cabbage ◽  
Volatile Organic ◽  
Order Of Magnitude

Abstract. We present the first laboratory experiments of aerosol formation from oxidation of volatile organic species emitted by living plants, a process which for half a century has been known to take place in the atmosphere. We have treated white cabbage plants with methyl jasmonate in order to induce the production of monoterpenes and certain less-volatile sesqui- and homoterpenes. Ozone was introduced into the growth chamber in which the plants were placed, and the subsequent aerosol formation and growth of aerosols were monitored by measuring the particle size distributions continuously during the experiments. Our observations show similar particle formation rates as in the atmosphere but much higher growth rates. The results indicate that the concentrations of nonvolatile oxidation products of plant released precursors needed to induce the nucleation are roughly an order-of-magnitude higher than their concentrations during atmospheric nucleation events. Our results therefore suggest that if oxidized organics are involved in atmospheric nucleation events, their role is to participate in the growth of pre-existing molecular clusters rather than to form such clusters through homogeneous or ion-induced nucleation.

Morphology Control, Dopant Incorporation, and Selective Epitaxial Growth of 4H-SiC at Low Temperatures Using CH3Cl Growth Precursor

2006 ◽  
Vol 911 ◽  
Author(s):  
Yaroslav Koshka ◽  
Bharat Krishnan ◽  
Huang-De Lin ◽  
Galyna Melnychuk
Keyword(s):  
Growth Rate ◽  
Low Temperature ◽  
Epitaxial Growth ◽  
Growth Surface ◽  
Epitaxial Layers ◽  
Selective Epitaxial Growth ◽  
Dopant Incorporation ◽  
Nitrogen Donor ◽  
Order Of Magnitude ◽  
Silicon Vapor

AbstractLow-temperature homoepitaxial growth of 4H-SiC using halo-carbon precursors was further investigated to address the problems limiting increase of the growth rate of the defect-free epilayers at growth temperatures below 1300°C. Enhanced etching of Si clusters in the gas phase was achieved by adding HCl during the low-temperature growth. The effective Si/C ratio above the growth surface was increased as a result of reduced depletion of silicon vapor species by cluster condensation, which resulted in drastically improved epilayer morphology and significant increase of the growth rate. An intentional insitu nitrogen doping of epitaxial layers during 1300°C growth on Si and C faces revealed more than an order of magnitude higher nitrogen donor incorporation in the C-face epitaxial layers. Finally, a feasibility of selective epitaxial growth using low-temperature masking materials such as SiO2 was demonstrated.

In situ B-doped Si epitaxial growth at low temperatures by atmospheric-pressure plasma CVD

2008 ◽  
Vol 40 (6-7) ◽  
pp. 984-987 ◽  
Author(s):  
Y. Kirihata ◽  
T. Nomura ◽  
H. Ohmi ◽  
H. Kakiuchi ◽  
K. Yasutake
Keyword(s):  
Epitaxial Growth ◽  
Atmospheric Pressure ◽  
Low Temperatures ◽  
Atmospheric Pressure Plasma ◽  
Plasma Cvd ◽  
Pressure Plasma

Fabrication of A Barium Titanate-Strontium Titanate Strained Layer Superlattice

1995 ◽  
Vol 397 ◽  
Author(s):  
S.D. Harkness ◽  
R.K. Singh
Keyword(s):  
Critical Thickness ◽  
Laser Deposition ◽  
Processing Conditions ◽  
X Ray Diffraction ◽  
X Ray ◽  
Force Microscopy ◽  
Atomic Force ◽  
Order Of Magnitude ◽  
Strained Layer Superlattice ◽  
Substrate Temperatures

ABSTRACTA thin film superlattice heterostructure composed of alternating BaTiO3 and SrTiO3 layers was grown on a thin YBa2Cu3O7 electrode templated on a (100) SrTiO3 wafer using the pulsed laser deposition method. Stranski-Krastanov nucleation of the layers was demonstrated using atomic force microscopy (AFM) when processing conditions were maintained at 6 millitorr oxygen partial pressure, and 550 °C substrate temperatures. High-resloution x-ray diffraction (HRXRD) measurements indicate that all the deformation was concentrated in the BaTiO3 layers with c/a extension to approximately 1.08. Rutherford backscattering spectroscopy (RBS) results indicate excellent crystallinity in the heterostructure. The microstructural data suggests that the theoretical critical thickness of the film has been surpassed by an order of magnitude.

scholarly journals Термоэлектрические свойства полуметаллических и полупроводниковых фольг и нитей Bi-=SUB=-1-x-=/SUB=-Sb-=SUB=-x-=/SUB=-

2019 ◽  
Vol 53 (5) ◽  
pp. 664
Author(s):  
А. Николаева ◽  
Л. Конопко ◽  
И. Гергишан ◽  
К. Рогацкий ◽  
П. Стачовик ◽  
...  
Keyword(s):  
Thermal Conductivity ◽  
Electrical Conductivity ◽  
Low Temperatures ◽  
Phonon Scattering ◽  
Surface States ◽  
Experimental Investigations ◽  
Quantum Size ◽  
Thermoelectric Energy ◽  
Conductive Surface ◽  
Order Of Magnitude

AbstractThe results of experimental investigations into the thermoelectric properties (electrical conductivity, thermoelectric power, and thermal conductivity) of microtextured foils and single-crystal wires based on semimetal and semiconductor Bi_1 –_ x Sb_ x alloys are presented in the temperature range of 4.2–300 K. It is found that the band gap Δ E in Bi–17 at % Sb wires increases with decreasing wire diameter d , which is a manifestation of the quantum-size effect. At low temperatures ( T < 50 K), in the wires with d < 400 nm, the electrical conductivity increases due to the significant contribution of highly conductive surface states characteristic of topological insulators. It is found for the first time that the thermal conductivity of semimetal Bi–3 at % Sb foils at low temperatures is two orders of magnitude lower, and that of semiconductor Bi–16 at % Sb foils one order of magnitude lower, than that in bulk samples of the corresponding composition due to significant phonon scattering at grain boundaries and surfaces. This effect leads to considerable enhancement of the thermoelectric figure-of-merit ZT and can be used in miniature low-temperature thermoelectric energy converters.

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