Sb Implantation in Si1–xGex/Si(100) Structures

1991 ◽  
Vol 235 ◽  
Author(s):  
Z. Atzmon ◽  
M. Eizenberg ◽  
P. Revesz ◽  
J. W. Mayer ◽  
F. Schäffler
Keyword(s):  
Short Distance ◽  
Room Temperature ◽  
Solid Phase ◽  
Amorphous Layer ◽  
Strained Si ◽  
Si Substrates ◽  
Epitaxial Regrowth ◽  
Heat Treated ◽  
Significant Difference ◽  
Initial Process

ABSTRACTSolid phase epitaxial regrowth of Sb implanted strained Si1−x Gex alloy layers is reported. Two sets of Si1–xGex alloys with compositions of x=0.08 and x=0.18, MBE grown on (100)Si substrates, were implanted at room temperature with Sb− ions at energies of 200 and 100 keV, respectively, and a dose of 1015cm−2. These alloys were heat-treated in a rapid thermal annealing system at temperatures of 525, 550 and 575°C for durations between 5 and 600 sec. The study of the solid phase epitaxial regrowth was performed by Rutherford backscattering in the channeling mode. The measurements show a significant difference in the regrowth mechanism between the two alloys. For the Si0.92Ge0.00 alloy a fast regrowth process (faster than for Sb implanted Si or Si implanted SiGe layers) occured with an activation energy of 2.92±0.2eV. For the Si0.02Ge0.10 alloy the regrowth took place in two steps: a) a very fast initial process over a short distance, b) a regrowth process of the majority of the amorphous layer.

Enhanced Boron Diffusion in Amorphous Silicon

2004 ◽  
Vol 810 ◽  
Author(s):  
J.M. Jacques ◽  
N. Burbure ◽  
K.S. Jones ◽  
M.E. Law ◽  
L.S. Robertson ◽  
...  
Keyword(s):  
Amorphous Silicon ◽  
Room Temperature ◽  
Solid Phase ◽  
Amorphous Layer ◽  
Boron Diffusion ◽  
Cross Sectional ◽  
Enhanced Diffusion ◽  
Transmission Electron ◽  
Variable Angle Spectroscopic Ellipsometry ◽  
Secondary Ion

ABSTRACTIn prior works, we demonstrated the phenomenon of fluorine-enhanced boron diffusion within self-amorphized silicon. Present studies address the process dependencies of low temperature boron motion within ion implanted materials utilizing a germanium amorphization. Silicon wafers were preamorphized with either 60 keV or 80 keV Ge+ at a dose of 1×1015 atoms/cm2. Subsequent 500 eV, 1×1015 atoms/cm211B+ implants, as well as 6 keV F+ implants with doses ranging from 1×1014 atoms/cm2 to 5×1015 atoms/cm2 were also done. Furnace anneals were conducted at 550°C for 10 minutes under an inert N2 ambient. Secondary Ion Mass Spectroscopy (SIMS) was utilized to characterize the occurrence of boron diffusion within amorphous silicon at room temperature, as well as during the Solid Phase Epitaxial Regrowth (SPER) process. Amorphous layer depths were verified through Cross-Sectional Transmission Electron Microscopy (XTEM) and Variable Angle Spectroscopic Ellipsometry (VASE). Boron motion within as-implanted samples is observed at fluorine concentrations greater than 1×1020 atoms/cm3. The magnitude of the boron motion scales with increasing fluorine dose and concentration. During the initial stages of SPER, boron was observed to diffuse irrespective of the co-implanted fluorine dose. Fluorine enhanced diffusion at room temperature does not appear to follow the same process as the enhanced diffusion observed during the regrowth process.

Analysis of junctions formed in strained Si/SiGe substrates

2004 ◽  
Vol 809 ◽  
Author(s):  
G. Eneman ◽  
E. Simoen ◽  
A. Lauwers ◽  
R. Lindsay ◽  
P. Verheyen ◽  
...  
Keyword(s):  
Buffer Layer ◽  
Room Temperature ◽  
Defect Density ◽  
Buffer Layers ◽  
Total Thickness ◽  
Strained Si ◽  
Si Substrates ◽  
Magnitude Increase

ABSTRACTJunctions were formed in thin SiGe/strained Si substrates with a thickness of 250-350 nm to assess the effect of different buffer layer parameters (bandgap, dislocations, thickness) on the junction leakage density that can be expected in MOSFET devices. The implantations used are standard well, channel and Highly Doped Drain (HDD) implants. Both p+/n and n+/p junctions were evaluated. The total thickness of the buffer layers was varied to compare the effect of different structural layers on the diode leakage. This investigation shows that the effect of an increased defect density is dominant at room temperature for the strained Si samples, resulting in 4-5 orders of magnitude increase in leakage. However, there is a different gradation in leakage dependence for thick and thin buffer layers, especially at higher temperatures.

(A)thermal migration of Ge during junction formation in s-Si layers grown on thin SiGebuffer layers

2004 ◽  
Vol 809 ◽  
Author(s):  
W. Vandervorst ◽  
B.J. Pawlak ◽  
T. Janssens ◽  
B. Brijs ◽  
R. Delhougne ◽  
...  
Keyword(s):  
Activation Energy ◽  
Distribution Function ◽  
Solid Phase ◽  
Silicon Layer ◽  
Damage Distribution ◽  
Strained Si ◽  
Advanced Technologies ◽  
Epitaxial Regrowth ◽  
Junction Formation ◽  
Determining Factor

ABSTRACTSolid phase epitaxial regrowth (SPER) has been proven to be highly advantageous for ultra shallow junction formation in advanced technologies. Application of SPER to strained Si/SiGe structures raises the concern that the Ge may out diffuse during the implantation and/or anneal steps and thus reduce the strain in the top silicon layer.In the present studies we expose 8-30 nm strained silicon layers grown on thin relaxed SiGe-buffers, to implant conditions and anneal cycles, characteristic for formation of the junctions by solid phase epitaxial regrowth and conventional spike activation. The resulting Geredistribution is measured using SIMS. Based on the outdiffused Ge-profiles the Ge-diffusion coefficient has been determined in the temperature range of 800-1100C from which an activation energy of ∼ 3.6 eV can be deduced. Up to 1050 C, 10 min, even a 30 nm strained film remains highly stable and shows only very moderate outdiffusion.We also have observed a far more efficient, athermal Ge-redistribution process linked to the implantation step itself. This was studied by analysing the Ge-redistribution following an Asimplant (2-15 keV, 5 1014 – 3 1015 at/cm2). It is shown that the energy of the implant species (or more specifically the position of the damage distribution function relative to the Ge-edge) plays a determining factor with respect to the Ge-migration. For implants whereby the damage distribution overlaps with the Ge-edge, a very efficient transport of the Ge is observed, even prior to any anneal cycle. The migration is entirely correlated with the collision cascade and the resulting (forward!) Ge-recoil distribution. The scaling with dose for a given energy links the observed Ge-profile with a broadening mechanism related to the number of atom displacements induced in the sample within the vicinity of the Si-SiGe-transition.

EQUALLY STRAINED Si/SiGe SUPERLATTICES ON Si SUBSTRATES

1985 ◽  
Vol 56 ◽  
Author(s):  
E. KASPER ◽  
H.-J. HERZOG ◽  
H.DAEMBKES-a1 ◽  
G. ABSTREITER
Keyword(s):  
Molecular Beam Epitaxy ◽  
Room Temperature ◽  
Molecular Beam ◽  
Electron Gas ◽  
Phonon Modes ◽  
Strained Si ◽  
Si Substrates ◽  
Device Applications ◽  
Strained Layer Superlattices ◽  
Material Concept

AbstractGrowth of Si/SiGe superlattices on Si substrates by molecular beam epitaxy (MBE) is described. Strain symmetrization in the superlattice is achieved with an incommensurate SiGe buffer layer. The concept of strainsymmetrization is explained and properties of buffer and strained layer superlattices are investigated. A twodimensional electron gas with enhanced room temperature mobility and folded phonon modes within the reduced onedimensional Brillouin zone are observed. An n-channel Si/SiGe MODFET demonstrates the device applications of this material concept.

Formation of Epitaxial Soi Structures Using Alkaline Earth Fltuoride Films

1985 ◽  
Vol 53 ◽  
Author(s):  
Hiroshi Ishiwara ◽  
Tanemasa Asano
Keyword(s):  
Alkaline Earth ◽  
Room Temperature ◽  
Solid Phase ◽  
Growth Conditions ◽  
Solid Phase Epitaxy ◽  
Si Substrates ◽  
Structural And Electrical Properties ◽  
Earth Fluoride ◽  
Alkaline Earth Fluoride ◽  
Device Applications

ABSTRACTRecent progress in the research of heteroepitaxial SOI structures such as Si/CaF2/Si and Ge/CaF2/Si structures is reviewed. Structural and electrical properties of alkaline earth fluoride films on Si substrates are first discussed. Growth conditions, structural properties, and device applications of the Si/CaF2/Si structures are then presented. It is shown that a predeposition technique, in which a thin Si layer is deposited at room temperature prior to the growth of a thick film at elevated temperature, is effective to improve the crystalline quality and the surface morphology of the film. Usefulness of solid phase epitaxy to obtain high quality films is also demonstrated. Finally, it is shown that the predeposition technique is also useful in formation of Ge/CaF2/Si structures.

Formation of β-FeSi2, by thermal annealing of Fe-implanted (001) Si

1993 ◽  
Vol 51 ◽  
pp. 808-809
Author(s):  
X.W. Lin ◽  
Z. Liliental-Weber ◽  
J. Washburn ◽  
J. Desimoni ◽  
H. Bernas
Keyword(s):  
Thermal Annealing ◽  
Room Temperature ◽  
Solid Phase ◽  
Ion Beam ◽  
High Resolution Electron Microscopy ◽  
Optoelectronic Device ◽  
Amorphous Layer ◽  
Cross Sectional ◽  
Resolution Electron ◽  
Device Technology

Epitaxy of semiconducting β-FeSi2 on Si is of interest for optoelectronic device technology, because of its direct bandgap of ≈0.9 eV. Several techniques, including solid phase epitaxy (SPE) and ion beam synthesis, have been successfully used to grow β-FeSi2 on either Si (001) or (111) wafers. In this paper, we report the epitaxial formation of β-FeSi2 upon thermal annealing of an Fe-Si amorphous layer formed by ion implantation.Si (001) wafers were first implanted at room temperature with 50-keV Fe+ ions to a dose of 0.5 - 1×1016 cm−2, corresponding to a peak Fe concentration of cp ≈ 2 - 4 at.%, and subsequently annealed at 320, 520, and 900°C, in order to induce SPE of the implanted amorphous layer. Cross-sectional high-resolution electron microscopy (HREM) was used for structural characterization.We find that the implanted surface layer ( ≈100 nm thick) remains amorphous for samples annealed at 320°C for as long as 3.2 h, whereas annealing above 520°C results in SPE of Si, along with precipitation of β-FeSi2.

Solid-Phase Epitaxial Regrowth and Dopant Activation of Arsenic. Implanted Metastable Pseudomorphic Ge0.08Si0.92 AND GeO.16SiO.84 ON Si(100)

1995 ◽  
Vol 379 ◽  
Author(s):  
D.Y.C. Lie ◽  
J.H. Song ◽  
M.-A. Nicolet ◽  
N.D. Theodore ◽  
J. Candelaria ◽  
...  
Keyword(s):  
Thermal Annealing ◽  
Rapid Thermal Annealing ◽  
Room Temperature ◽  
Solid Phase ◽  
Strain Relaxation ◽  
Chemical Vapor ◽  
Layer By Layer ◽  
Solid Phase Epitaxy ◽  
Epitaxial Regrowth ◽  
Control Samples

ABSTRACTMetastable pseudomorphic GexSi1−x (x=8%,16%) films were deposited on p-Si(100) substrates by chemical-vapor-deposition and then implanted at room temperature with 90 keV arsenic ions to a dose of 1.5×1015/cm2. The implantation amorphizes approximately the top 125 nm of the 145 nm-thick GeSi layers. The Si-GeSi interfaces remain sharp after implantation. Implanted and non-implanted GeSi samples, together with implanted Si control samples, were subsequently annealed simultaneously by rapid thermal annealing in a nitrogen ambient at 600,700,800 × for 10,20,40s at each temperature. The implanted samples undergo layer-by-layer solid-phase epitaxial regrowth during annealing at or above 600 ×C. The amorphized and regrown GeSi layers are always fully relaxed with a very high density of dislocations (1010-1011/cm2). At a fixed annealing temperature, strain relaxation of an implanted GeSi film is substantially more extensive than that of a non-implanted one. About 50-90% of the implanted arsenic ions become electrically active after the completion of solid-phase epitaxy. The percentages of arsenic ions that are activated in the Si control samples are generally higher than those in GeSi. The room-temperature sheet electron mobility in GeSi is roughly 30% lower than that in Si for a given sheet electron concentration. We conclude that metastable GeSi on Si(100) amorphized by arsenic ions and recrystallized by solid-phase epitaxy cannot recover both its crystallinity and its pseudomorphic strain under rapid thermal annealing.

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.

Dopant Activation And Epitaxial Regrowth in P-Implanted Pseudomorphic Ge0.12Si0.88 Layers on Si (100)

1993 ◽  
Vol 321 ◽  
Author(s):  
D. Y. C. Lie ◽  
T. K. Cams ◽  
N. D. Theodore ◽  
F. Eisen ◽  
M.-A. Nicolet ◽  
...  
Keyword(s):  
Molecular Beam Epitaxy ◽  
Film Thickness ◽  
Electron Mobility ◽  
Room Temperature ◽  
Molecular Beam ◽  
Solid Phase ◽  
Dopant Activation ◽  
Projected Range ◽  
Epitaxial Regrowth ◽  
Virgin Sample

AbstractA pseudomorphic Ge0.12Si0.88 film 265 nm thick grown on a Si (100) substrate by molecular beam epitaxy was implanted at room temperature with a dose of 1.5 × 1015 cm2 of 100 keV P ions. The projected range of the ions is about 125 nm, which is well within the film thickness. Only the top portion of the Ge0.12Si0.88 layer was amorphized by the implantation. Both implanted and non-implanted samples were subsequently annealed in vacuum for 30 Minutes from 400 °C to 800 °C. Values of electron Hall sheet mobility and concentration in the implanted Ge0.12Si0.88 epilayer were measured after annealing. The solid phase epitaxial regrowth is complete at 550 °C, where the implanted phosphorus reaches - 100 % activation. The regrown Ge0.12Si0.88 layer exhibits inferior crystalline quality to that of the virgin sample and is relaxed, but the non-implanted portion of the film remains pseudomorphic at 550 °C. When annealed at 800 °C, the strain in the whole epilayer relaxes. The sheet electron mobility values measured at room temperature in the regrown samples (Tann ≥ 550 °C) are about 20% less than those of pure Si.

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.

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