Solid-Phase Epitaxial Crystallisation of GexSi1-x Alloy Layers

1993 ◽  
Vol 316 ◽  
Author(s):  
Robert G. Elliman ◽  
Wah-Chung Wong ◽  
Per KringhØj
Keyword(s):  
Solid Phase ◽  
Ion Beam ◽  
Strain Relaxation ◽  
Strained Si ◽  
Strained Layers ◽  
Thermally Induced ◽  
Simple Extrapolation ◽  
Annealing Experiments ◽  
Uniform Composition ◽  
Sudden Reduction

ABSTRACTThermally-induced solid-phase epitaxial crystallisation (SPEC) and ion-beam-induced epitaxial crystallisation (IBIEC) of amorphous GexSi1-x alloy layers is examined for three different starting structures: a) strain-relaxed alloy layers of uniform composition, b) strained alloy layers of uniform composition, and c) Ge implanted Si layers. Thermal annealing experiments show that the activation energy for strain-relaxed alloys is higher than that expected from a simple extrapolation between the activation energies of Si and Ge, and exceeds that of Si for x ≤ 0.3. Experiments on thin strained layers show that MBE grown strained layers which are stable during annealing at 1100°C for 60 s are also fully strained after SPEC, whereas layers which relax during annealing at 1100°C also relax during SPEC. Experiments on ion-implanted GeχSiι_x structures show that fully strained Si/GexSi1-x /Si heterostructures can be fabricated for ion fluences below a critical fluence, and as for uniform alloy layers that this critical fluence is accurately predicted by equilibrium theory. Strain relaxation during SPEC of uniform alloys and implanted structures is shown to be correlated with a sudden reduction in crystallisation velocity which is believed to be caused by stress-induced roughening or faceting of the crystalline/amorphous interface. IBIEC of thick (800 nm) implanted layers is shown to be limited by competition from ion-beam induced random crystallisation, while thin (120 nm) uniform alloys and implanted structures are shown to crystallise ephaxially and to exhibit similar behaviour to thermally annealed samples under certain conditions.

Solid-Phase Epitaxial Crystallisation Of GexSi1−x Alloy Layers

1993 ◽  
Vol 321 ◽  
Author(s):  
Robert G. Elliman ◽  
Wah-Chung Wong ◽  
Per Kringhøj
Keyword(s):  
Solid Phase ◽  
Ion Beam ◽  
Strain Relaxation ◽  
Strained Si ◽  
Strained Layers ◽  
Thermally Induced ◽  
Simple Extrapolation ◽  
Annealing Experiments ◽  
Uniform Composition ◽  
Sudden Reduction

ABSTRACTThermally-induced solid-phase epitaxial crystallisation (SPEC) and ion-beam-induced epitaxial crystallisation (IBffiC) of amorphous GexSi1−x alloy layers is examined for three different starting structures: a) strain-relaxed alloy layers of uniform composition, b) strained alloy layers of uniform composition, and c) Ge implanted Si layers. Thermal annealing experiments show that the activation energy for strain-relaxed alloys is higher than that expected from a simple extrapolation between the activation energies of Si and Ge, and exceeds that of Si for x ≤ 0.3. Experiments on thin strained layers show that MBE grown strained layers which are stable during annealing at 1100°C for 60 s are also fully strained after SPEC, whereas layers which relax during annealing at 1100°C also relax during SPEC. Experiments on ion-implanted GexSi1−x structures show that fully strained Si/GexSi1−x/Si heterostructures can be fabricated for ion fluences below a critical fluence, and as for uniform alloy layers that this critical fluence is accurately predicted by equilibrium theory. Strain relaxation during SPEC of uniform alloys and implanted structures is shown to be correlated with a sudden reduction in crystallisation velocity which is believed to be caused by stress-induced roughening or faceting of the crystalline/amorphous interface. SPEC of thick (800 nm) implanted layers is shown to be limited by competition from ion-beam induced random crystallisation, while thin (120 nm) uniform alloys and implanted structures are shown to crystallise epitaxially and to exhibit similar behaviour to thermally annealed samples under certain conditions.

Time-Resolved Reflectivity Study of Solid-Phase Epitaxial Regrowth in Relaxed and Strained Si1−xGex Epilayers

1992 ◽  
Vol 281 ◽  
Author(s):  
T. E. Haynes ◽  
C. Lee ◽  
K. S. Jones
Keyword(s):  
Composition Dependence ◽  
Solid Phase ◽  
Strain Relaxation ◽  
Alloy Layer ◽  
Atomic Fraction ◽  
Bulk Alloy ◽  
Strained Layers ◽  
Time Resolved ◽  
Epitaxial Regrowth ◽  
Different Types

ABSTRACTThe rate of solid-phase epitaxial regrowth has been studied using time-resolved reflectivity in three different types of SiGe/Si epilayers amorphized by ion implantation. In two of these cases, the alloy epilayer contained either 12% or 20% Ge, and the amorphization depth was greater than the thickness (2000 Å) of the SiGe alloy layer. Time-resolved reflectivity measurements showed that the rate of regrowth was not constant in these two cases, but first decreased after passing the SiGe/Si interface, and then increased. The minimum regrowth rate occurred closer to the SiGe/Si interface in the epilayers with the larger Ge atomic fraction. In the third type of sample, the alloy epilayer thickness was ∼7μm, so that the initial epilayer (15% Ge) had the lattice constant of the bulk alloy. Furthermore, amorphization and regrowth occurred entirely within the relaxed alloy layer. In this case, the regrowth rate was constant. The composition dependence of the regrowth-rate transient in the strained layers is discussed in the context of a ‘critical-thickness’ model of strain relaxation.

The Fabrication of High-Speed Electronic Devices by Ion-Beam Synthesis of GexSi1-x Strained Layers

1996 ◽  
Vol 438 ◽  
Author(s):  
R. G. Elliman ◽  
H. Jiang ◽  
W. C. Wong ◽  
P. Kringhøj
Keyword(s):  
Oxidation Rate ◽  
Field Effect ◽  
High Speed ◽  
Materials Science ◽  
Field Effect Transistors ◽  
Solid Phase ◽  
Ion Beam ◽  
Electronic Devices ◽  
Solid Phase Epitaxy ◽  
Strained Layers

AbstractGexSi1-x, strained layers can be fabricated by Ge implantation and solid-phase epitaxy and can be used in electronic devices to improve their performance. Several important materials science issues are addressed, including the effect of the strain on solid-phase-epitaxy, the effect of oxidation on the implanted Ge distribution, and the effect of Ge on the oxidation rate of Si. The potential of this process is demonstrated by comparing the performance of metal-oxidesemiconductor field-effect-transistors (MOSFETs) employing ion-beam synthesised GeSi strained layer channel regions with that of Si-only devices.

The effect of annealing environments on the epitaxial recrystallization of ion-beam-amorphized SrTiO3

1992 ◽  
Vol 7 (3) ◽  
pp. 717-724 ◽  
Author(s):  
J. Rankin ◽  
J.C. McCallum ◽  
L.A. Boatner
Keyword(s):  
Activation Energy ◽  
Solid Phase ◽  
Ion Beam ◽  
Amorphous Layer ◽  
Surface Layers ◽  
Time Resolved ◽  
Near Surface ◽  
Thermally Induced ◽  
Stage Process ◽  
Single Constant

Time-resolved reflectivity and Rutherford backscattering spectroscopy were used to investigate the effects of regrowth environments on the thermally induced solid phase epitaxial (SPE) regrowth of amorphous near-surface layers produced by ion implantation of single-crystal SrTiO3. Water vapor in the regrowth atmosphere was found to alter both the apparent rate and activation energy of the SPE regrowth. For relatively dry atmospheres, a single constant regrowth rate is observed at any given temperature, and the activation energy is 1.2 ± 0.1 eV. When the concentration of H2O vapor in the atmosphere is increased, however, the regrowth activation energy effectively decreases to ∼0.95 eV. When regrown in atmospheres containing H2O vapor, the SrTiO3 amorphous layer exhibits two distinct stages of SPE regrowth as compared to the single rate found for dry anneals. This two-stage process apparently results from the diffusion of H/OH from the regrowth atmosphere at the surface of the crystal through the amorphous layer to the regrowing crystalline/amorphous interface.

Solid Phase Epitaxy of Si1-xGex on Si Strained Layers

1989 ◽  
Vol 160 ◽  
Author(s):  
B.J. Robinson ◽  
B.T. Chilton ◽  
P. Ferret ◽  
D.A. Thompson
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Solid Phase ◽  
Strain Relaxation ◽  
Crystal Quality ◽  
Solid Phase Epitaxy ◽  
Strained Layers ◽  
Transmission Electron ◽  
Layer Structures

AbstractSingle strained layer structures of up to 30 nm of Si1-xGex. on (100) Si and capped with 30-36 nm of Si have been amorphized by implantation with 120 keV As . The amorphized region, extending to a depth of 130 nm, has been regrown by solid phase epitaxy (SPE) at 600°C. Characterization of the regrown structure by Rutherford backscattering/channeling techniques and transmission electron microscopy indicates that for x < 0.18 the SPE process results in the recovery of strain, while for x > 0.18 there is increasing strain relaxation and a deterioration of crystal quality.

Study of Strain Relaxation in Epitaxial Structure Ge0.2 Si0.8/Si At Thermo-Implantation Treatment by Ion Beam Channeling

1999 ◽  
Vol 585 ◽  
Author(s):  
A. F. Vyatkin ◽  
V. K. Egorov ◽  
E. V. Egorov
Keyword(s):  
Radiation Damage ◽  
Ion Beam ◽  
Strain Relaxation ◽  
Strained Si ◽  
Epitaxial Structure

AbstractStrain relaxation in epitaxial Si-Ge structures induced by ion beam bombardment has been studied using a He+ channeling technique. It is shown that hot ion beam bombardment (230°C, Si+ ions with energy 200 keV and fluence 6·1013 ion/cm2) of thin strained Si-Ge layers results in partial strain relaxation. A model of the strain relaxation induced by radiation damage is proposed.

Comparison Between Ion-Beam and Thermal-Annealing Induced Solid Phase Epitaxy in Fe-Implanted Si

1993 ◽  
Vol 320 ◽  
Author(s):  
X.W. Lin ◽  
J. Desimoni ◽  
H. Bernas ◽  
Z. Liliental-Weber ◽  
J. Washburn
Keyword(s):  
Electron Microscopy ◽  
Thermal Annealing ◽  
Rutherford Backscattering Spectrometry ◽  
Solid Phase ◽  
Ion Irradiation ◽  
Ion Beam ◽  
Solid Phase Epitaxy ◽  
Thermally Induced ◽  
Transmission Electron ◽  
Visible Effect

Rutherford backscattering spectrometry and transmission electron microscopy were used to compare thermally induced solid phase epitaxy (SPE) with ion-beam induced epitaxial crystallization (IBIEC) of Fe-implanted Si (001). It was found that thermal annealing leads to both Si SPE and β-FeSi2 precipitation at 520°C, but has no visible effect at 320°C. In contrast, Si SPE and FeSi2 precipitation occur at both 320 and 520°C, when ion irradiation is introduced. The precipitates grow epitaxially as γ-FeSi2 at 320°C, but consist of both β-FeSi2 and γ-FeSi2 at 520°C. It was also found that thermal annealing at 520°C results in Fe segregation toward the surface, while IBIEC basically retains the as-implanted Fe profile.

Dynamical X-ray diffraction analysis of Solid Phase Epitaxy growth of Si1-yCy heterostructures

2000 ◽  
Vol 647 ◽  
Author(s):  
J. Rodriguez-Viejo ◽  
Zakia el-Felk
Keyword(s):  
Secondary Ion Mass Spectrometry ◽  
Solid Phase ◽  
Strain Relaxation ◽  
Liquid Nitrogen Temperature ◽  
Amorphous Layer ◽  
Epitaxial Films ◽  
High Dose ◽  
X Ray Diffraction ◽  
Strained Si ◽  
X Ray

AbstractThe strain and damage produced on Si substrates by high-dose ion implantation of Si and C is investigated after thermal treatments by double and triple crystal X-ray diffraction, high ressolution transmission electron microscopy (HRTEM) and Secondary Ion Mass Spectrometry (SIMS). Si implantation (180 keV, 5×1015 Si at cm−2) at liquid nitrogen temperature forms a buried amorphous layer. Annealing at temperatures close to 650°C results in epitaxial films with significant defect recovery. X-ray rocking curves show the existence of interference fringes on the left hand side of the 004 Si peak indicating the presence of tensile strained Si layers due to the generation of Si interstitials during the implantation process. C implantation, at 60 keV, 7×1015 cm−2 and 450°C, in the preamorphized Si wafers results in the growth of Si1-yCy epitaxial films with a low amount of substitutional carbon (y≍ 0.1%). Rapid thermal annealing at 750°C results in highly defective epitaxial films with a maximum carbon content close to 0.4%.The high density of defects is responsible for the partial strain relaxation observed in those layers. The amount of substitutional Si also decreases drastically with increasing temperature. Profile fitting of rocking curves using dynamical X-ray theory is used to estimate the C concentration and the strain and disorder profiles of the heterostructures.

Solid Phase Recrystallization and Strain Relaxation in Ion-Implanted Strained Si on SiGe Heterostructures

2005 ◽  
Vol 864 ◽  
Author(s):  
M.S. Phen ◽  
R. T. Crosby ◽  
V. Craciun ◽  
K. S. Jones ◽  
M.E. Law ◽  
...  
Keyword(s):  
Molecular Beam ◽  
Solid Phase ◽  
Strain Relaxation ◽  
Amorphous Layer ◽  
Strained Silicon ◽  
X Ray Diffraction ◽  
Strained Si ◽  
Mbe Growth ◽  
Capping Layer ◽  
X Ray

AbstractThe relaxation process of strained silicon films on silicon-rich relaxed SiGe alloys has been studied. Experimental structures were grown via Molecular Beam Epitaxy (MBE) growth techniques and contain a strained silicon capping layer approximately 50 nm thick. The relaxed SiGe alloy compositions range from 0 to 30 at.% germanium. A 12 keV Si+ implant at a dose of 1×1015 atoms/cm2 was used to generate an amorphous layer ∼30 nm thick, which was confined within the strained silicon capping layer. Upon annealing at 500 °C, it was found that the solid phase epitaxial regrowth process of the amorphous silicon breaks down for high strain levels and regrowth related defects were observed in the regrown layer. In addition, high-resolution X-Ray diffraction results indicate a reduction in strain for the silicon capping layer. This study addresses the critical strain regime necessary for the breakdown of solid phase epitaxial recrystallization in silicon.

Schottky Barrier Heights of A1/p-Sil-xGex

1995 ◽  
Vol 379 ◽  
Author(s):  
R. L. Jiang ◽  
J. Li ◽  
X. C. Zhou ◽  
J. N. Liu ◽  
Y. D. Zheng
Keyword(s):  
Schottky Barrier ◽  
Schottky Barrier Height ◽  
Strain Relaxation ◽  
Chemical Vapor ◽  
Schottky Contacts ◽  
Rapid Thermal Process ◽  
Strained Si ◽  
Strained Layers ◽  
Barrier Heights ◽  
Pressure Chemical

ABSTRACTElectrical properties of Al/p-Sil-xGex Schottky contacts were investigated. The Sil-xGexstrained layers were grown by using Rapid Thermal Process/Very Low Pressure-Chemical Vapor Deposition. It was found that Schottky barrier height decreased with increasing Ge fraction. The decrement is in accordance with the decrement of the bandgap of the strained Sil-xGex. The Fermi level at the interface is pinned at about 0. 43eV below the conduction band. The influence of strain relaxation for SiGe alloy layers and the Si cap layers on the properties of Schottky contacts were also investigated.

Sign in / Sign up

Export Citation Format

Share Document