Ge+ Preamorphization of Si: Effects of Dose and Very Low Temperature Thermal Treatment on Extended Defect Formation During Subsequent Spe

1985 ◽  
Vol 52 ◽  
Author(s):  
E. Myers ◽  
G. A. Rozgonyi ◽  
D. K. Sadana ◽  
W. Maszara ◽  
J. J. Wortman ◽  
...  
Keyword(s):  
Phase Transition ◽  
Low Temperature ◽  
Defect Formation ◽  
Solid Phase ◽  
Amorphous Material ◽  
Dose Range ◽  
Amorphous Layer ◽  
Extended Defect ◽  
Transmission Electron ◽  
Very Low Temperature

ABSTRACTCross-section transmission electron microscopy (X-TEM) has been used to illustrate the amornhous/ crystalline (a/c) micromorphology dependence of various low dose Ge+ preamorphizatlon implants in Si. Ge+ Implants were done at room _emperature at energies of 150 and 300 keV in the dose range of 1 to 9E14 cm−2. These implants result in the formation of either a buried or a continuous amorphous layer, with rough a/c interfaces. Nucleation of spanning “hairpin” dislocations during subsequent solid phase epltaxy (SPE) regrowth is known to be related to rough a/c interface morphology. Very low temperature anneals (VLTA),less than 500°C where the rate of SPE is minimal, were utilized to sharpen rough a/c interfaces prior to subsequent SPE regrowth. Sharpening of rough a/c interfaces is shown to result from an unexpected reverse crystalline to amorphous phase transition. This reverse phase transition results in the dissolution of detached microcrystallltes located within the amorphous layer near the a/c interface. Utilization of VLTA interfacial smoothing prior to SPE regrowth therfore, results in the reduction of residual spanning “hairpin” dislocations along with homogenization of the amorphous material.

The Effect of Oxide Trenches on Defect Formation and Evolution in Ion-Implanted Silicon

2004 ◽  
Vol 810 ◽  
Author(s):  
Nina Burbure ◽  
Kevin S. Jones
Keyword(s):  
Silicon Oxide ◽  
Defect Formation ◽  
Solid Phase ◽  
Amorphous Layer ◽  
Oxide Interface ◽  
Cross Sectional ◽  
Patterned Wafers ◽  
Edge Defects ◽  
Formation And Evolution ◽  
Spike Anneal

ABSTRACTPattern induced defects during advanced CMOS processing can lead to lower quality devices with high leakage currents. Within this study, the effects of oxide trenches on implant related defect formation and evolution in silicon patterned wafers is examined. Oxide filled trenches approximately 4000Å deep were patterned into 300 mm <100> silicon wafers. Patterning was followed by ion implantation of Si+ at energies ranging from 10 to 80 keV. Samples were amorphized with doses of 1×1015 atoms/cm2, 5×1015 atoms/cm2, and 1×1016 atoms/cm2. Two independent repeating structures were studied. The first structure is comprised of silicon oxide filled trench lines, 3.7μm wide spaced 12.5μm apart, while the second structure contains silicon squares, 0.6μm on a side, surrounded by a silicon oxide filled trench. Cross- sectional and planar view transmission electron microscopy (TEM) samples were used to examine the defect morphology after annealing at temperatures ranging from 700°C to 950°C and at times between 1 second and 1 minute. Following complete regrowth, an array of defects was observed to form near the surface at the silicon/silicon oxide interface. These trench edge defects appeared to nucleate at the amorphous-crystalline interface for all energies and doses studied. Upon a spike anneal at 700°C, it was observed that regrowth of the amorphous layer had completed except in the region near the trench edge. Thus, it is believed that this defect results from the pinning of the amorphous-crystalline interface along the trench edge during solid phase epitaxial regrowth (SPER).

Epitaxy and Nucleation in Cu and Ag Doped Amorphous Si

1990 ◽  
Vol 205 ◽  
Author(s):  
J. S. Custer ◽  
Michael O. Thompson ◽  
D. J. Eaglesham ◽  
D. C. Jacobson ◽  
J. M. Poate ◽  
...  
Keyword(s):  
Solid Phase ◽  
Amorphous Material ◽  
Intrinsic Rate ◽  
Amorphous Layer ◽  
Solid Phase Epitaxy ◽  
Small Deviations ◽  
Random Nucleation ◽  
Low Concentrations ◽  
Critical Metal ◽  
Amorphous Si

AbstractThe competition between solid phase epitaxy and random nucleation during thermal annealing of amorphous Si implanted with the fast diffusers Cu and Ag has been studied. For low concentrations of these impurities, solid phase epitaxy proceeds with small deviations from the intrinsic rate and with the impurity remaining in the shrinking amorphous layer. At a critical metal concentration in the amorphous layer of ∼ 0.12 at.% rapid random nucleation occurs, halting epitaxy and transforming the remaining amorphous material to polycrystalline Si via grain growth. The nucleation rate is at least 8 orders of magnitude greater than the intrinsic homogeneous rate. At higher Cu concentrations nucleation is observed below the temperature needed for epitaxy (400°C). This nucleation, clearly caused by the presence of Cu or Ag in the layer, may be induced by the impurities exceeding the absolute stability concentration and starting to phase separate, leading to enhanced crystal Si nucleation in the metal rich regions.

Low-Temperature, Solid-Phase Epitaxial Growth of Amorphized, Non-Stoichiometric GaAs

1995 ◽  
Vol 378 ◽  
Author(s):  
K. B. Belay ◽  
D. L. Llewellyn ◽  
M. C. Ridgway
Keyword(s):  
Low Temperature ◽  
Epitaxial Growth ◽  
Rutherford Backscattering Spectrometry ◽  
Solid Phase ◽  
Present Report ◽  
Time Resolved ◽  
Crystalline Layer ◽  
Transmission Electron ◽  
High Doses ◽  
Insulating Properties

AbstractNon-stoichiometric GaAs layers with semi-insulating properties can be produced by low-temperature molecular beam epitaxy or ion implantation. The latter is the subject of the present report wherein the solid-phase epitaxial growth of amorphized, non-stoichiometric GaAs layers has been investigated with time-resolved reflectivity, Rutherford backscattering spectrometry and transmission electron microscopy. GaAs substrates were implanted with Ga and/or As ions and annealed in air at a temperature of 260°C. The recrystallized material was composed of a thin, crystalline layer bordered by a thick, twinned layer. Non-stoichiometry results in a roughening of the amorphous/crystalline interface and the transformation from planar to non-planar regrowth. The onset of the transformation and the rate thereof can increase with an increase in non-stoichiometry. Non-stoichiometry can be achieved on a macroscopic scale via Ga or As implants or on a microscopic scale via Ga and As implants. The influence of the latter is greatest at low doses whilst the former dominates at high doses.

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.

Light Absorption Effects on the Nd Laser Annealing of Ion Implanted Silicon

1981 ◽  
Vol 4 ◽  
Author(s):  
P. Baeri ◽  
A.E. Bapbarino ◽  
S.U. Campisano ◽  
M.G. Grimaldi ◽  
G. Foti ◽  
...  
Keyword(s):  
Energy Density ◽  
Heat Flow ◽  
Low Temperature ◽  
Laser Annealing ◽  
Amorphous Material ◽  
Amorphous Layer ◽  
Absorbed Energy ◽  
Pre Treatment ◽  
Crystallization Onset ◽  
Ion Implanted

ABSTRACTThe crystallization onset and the annealing thresholds have been nmeasured as a function of the absorbed energy density in ion implanted amorphous silicon irradiated with nanosecond Nd pulse. Thin amorphous layers (∼500 Å) require higher thresholds ccapared with thick (∼4000 Å) amorphous layers. This result can be explained in terms of balance between absorbed energy and heat flow. For a given thickness of the amorphous layer the thresholds depend on the absorption coefficient of the amorphous material. This last parameter has been varied frcm 104 to 102 CM−1 by low temperature (T<400°C) pre-treatment of the ion implanted sample. The observed drastic variations of both crystallizazion and annealing thresholds agree well with nunerical evaluation of heat flow.

The Role of Stress on the Shape of the Amorphous-Crystalline Interface and Mask-Edge Defect Formation in Ion-Implanted Silicon

2004 ◽  
Vol 810 ◽  
Author(s):  
Carrie E. Ross ◽  
Kevin S. Jones
Keyword(s):  
Defect Formation ◽  
Region Of Interest ◽  
Amorphous Layer ◽  
Uniaxial Tensile ◽  
Cross Sectional ◽  
Transmission Electron ◽  
Patterned Structures ◽  
Uniaxial Tensile Stress ◽  
Mask Edge

ABSTRACTStress is known to affect the regrowth velocities during recrystallization of an amorphous layer. This study investigates how the stress from patterned structures alters regrowth and in turn affects defect formation. Prior to patterning, 80Å SiO2 and 1540Å of silicon nitride were deposited on a 200 mm [001] silicon wafer. A 40keV Si+ amorphizing implant at a dose of 1×1015 atoms/cm2 was then performed into the patterned wafer. The regrowth of the amorphous layer along the mask edge was studied by partially recrystallizing the layer for various times at 550°C both with the mask present and after etching off the oxide and nitride pads. A significant number of cross-sectional Transmission Electron Microscopy (TEM) samples were prepared and imaged. It was found that the stress from the patterned structures enhances the vertical and lateral regrowth velocities, as well as alters the shape of the amorphous-crystalline interface during regrowth. Previous studies have shown that uniaxial tensile stress increases the regrowth velocity. Simulations show that the region of interest in these samples is under tensile stresses, suggesting that this type of stress should accelerate the regrowth velocity. In addition dislocation half loops are observed to form along the mask edge for certain structures. The nucleation of these defects is suppressed by the presence of the film. The relationship between the stress from the patterned structures, the regrowth of the amorphous layer, and the formation of dislocation half-loops along the mask edge will be discussed.

Extended Defects in Amorphized and Rapid-Thermally Annealed Silicon

1985 ◽  
Vol 52 ◽  
Author(s):  
D. M. Maher ◽  
R. V. Knoell ◽  
M. B. Ellington ◽  
D. C. Jacobson
Keyword(s):  
Solid Phase ◽  
Analytical Techniques ◽  
Extended Defects ◽  
Final States ◽  
Defect States ◽  
Extended Defect ◽  
Ion Channeling ◽  
Transmission Electron ◽  
Initial States

ABSTRACTThe characterization of microstructures is fundamentally important to investigations of amorphization which is induced by ion implantation and recrystallization which occurs by solid-phase, epitaxial regrowth. In this paper, microstructures of amorphized, partially regrown and fully regrown layers are described in terms of extended-defect states of the material. Initial states (i.e. amorphized) and final states (i.e. solid-phase regrown and then reordered) are defined. Transmission electron microscopy and Rutherford backscattering/ion-channeling are the analytical techniques which are used in the characterization.

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