Solute Segregation and Dynamics of Solid-Phase Crystallization In in and Sb-Implanted Silicon

1981 ◽  
Vol 4 ◽  
Author(s):  
J. Narayan ◽  
G. L. Olson ◽  
O. W. Holland

ABSTRACTTime-resolved-reflectivity measurements have been combined with transmission electron microscopy (cross-section and plan-view), Rutherford backscattering and ion channeling techniques to study the details of laser induced solid phase epitaxial growth in In+ and Sb+ implanted silicon in the temperature range from 725 to 1500 °K. The details of microstructures including the formation of polycrystals, precipitates, and dislocations have been correlated with the dynamics of crystallization. There were limits to the dopant concentrations which could be incorporated into substitutional lattice sites; these concentrations exceeded retrograde solubility limits by factors up to 70 in the case of the Si-In system. The coarsening of dislocation loops and the formation of a/2<110>, 90° dislocations in the underlying dislocation-loop bands are described as a function of laser power.

1993 ◽  
Vol 298 ◽  
Author(s):  
Gang He ◽  
Mark D. Savellano ◽  
Harry A. Atwater

AbstractSynthesis of strain-compensated single-crystal Siy(SnxC1-x)1-y alloy films on silicon (100) substrates has been achieved with compositions of tin and carbon greatly exceeding their normal equilibrium solubility in silicon. Amorphous SiSnC alloys were deposited by molecular beam deposition from solid sources followed by thermal annealing. In situ monitoring of crystallization was done using time-resolved reflectivity. Good solid phase epitaxy was observed for Si0.98Sn0.01C0.01, at a rate about 20 times slower than that of pure silicon. Compositional and structural analysis was done using Rutherford backscattering, electron microprobe, ion channeling, x-ray diffraction, and transmission electron microscopy.


1995 ◽  
Vol 379 ◽  
Author(s):  
M.J. Antonell ◽  
T.E. Haynes ◽  
K.S. Jones

ABSTRACTTransmission electron microscopy has been combined with time-resolved reflectivity and ion channeling to study the effects of regrowth temperature and carbon introduction by ion implantation on the solid phase epitaxial regrowth (SPER) of strained 2000Å, Sio.88Ge0.12/Si alloy films grown by molecular-beam epitaxy (MBE). Relative to the undoped layers, carbon incorporation in the MBE grown SiGe layers prior to regrowth at moderate temperatures (500- 700°C) has three main effects on SPER; these include a reduction in SPER rate, a delay in the onset of strain-relieving defect formation, and a sharpening of the amorphous-crystalline (a/c) interface, i.e., promotion of a two-dimensional (planar) growth front.1 Recrystallization of amorphized SiGe layers at higher temperatures (1 100°C) substantially modifies the defect structure in samples both with and without carbon. At these elevated temperatures threading dislocations extend completely to the Si/SiGe interface. Stacking faults are eliminated in the high temperature regrowth, and the threading dislocation density is slightly higher with carbon implantation.


1992 ◽  
Vol 02 (02) ◽  
pp. 151-159
Author(s):  
LIU SHIJIE ◽  
WANG JIANG ◽  
HU ZAOHUEI ◽  
XIA ZHONGHUONG ◽  
GAO ZHIGIANG ◽  
...  

GaAs (100) crystals were implanted with 100 keV S+ to a dose of 3×1015 cm−2 in a nonchanneling direction at room temperature, and treated with rapid thermal annealing (RTA). He+ Rutherford backscattering and particle-induced X-ray emission in channeling mode in combination with transmission electron microscopy (TEM) were used to study the damage and the lattice location of S atoms. It is revealed that the RTA at 950 °C for 10 sec has resulted in a very good recovery of crystallinity with a few residual defects in the form of dislocation loops, and a very high substitutionality (~90%). The activation efficiency and the Hall mobility of the implanted samples are found to be low after the electrical measurements. Based on these results an extended dopant diffusion effect for the residual defects and a correlation between the electrical properties and defect complexes are suggested.


1995 ◽  
Vol 378 ◽  
Author(s):  
R. H. Thompson ◽  
V. Krishnamoorthy ◽  
J. Liu ◽  
K. S. Jones

AbstractP-type (100) silicon wafers were implanted with 28Si+ ions at an energy of 50 keV and to doses of 1 × 1015, 5 × 1015 and 1 × 1016 cm−2, respectively, and annealed in a N2 ambient at temperatures ranging from 700°C to 1000°C for times ranging from 15 minutes to 16 hours. The resulting microstructure consisted of varying distributions of Type II end of range dislocation loops. The size distribution of these loops was quantified using plan-view transmission electron microscopy and the strain arising from these loops was investigated using high resolution x-ray diffraction. The measured strain values were found to be constant in the loop coarsening regime wherein the number of atoms bound by the loops remained a constant. Therefore, an empirical constant of 7.7 × 10−12 interstitial/ppm of strain was evaluated to relate the number of interstitials bound by these dislocation loops and the strain. This value was used successfully in estimating the number of interstitials bound by loops at the various doses studied provided the annealing conditions were such that the loop microstructure was in the coarsening or dissolution regime.


1993 ◽  
Vol 319 ◽  
Author(s):  
X. J. Ning ◽  
P. Pirouz

AbstractDespite tremendous activity during the last few decades in the study of strain relaxation in thin films grown on substrates of a dissimilar material, there are still a number of problems which are unresolved. One of these is the nature of misfit dislocations forming at the film/substrate interface: depending on the misfit, the dislocations constituting the interfacial network have predominantly either in-plane or inclined Burgers vectors. While, the mechanisms of formation of misfit dislocations with inclined Burgers vectors are reasonably well understood, this is not the case for in-plane misfit dislocations whose formation mechanism is still controversial. In this paper, misfit dislocations generated to relax the strains caused by diffusion of boron into silicon have been investigated by plan-view and crosssectional transmission electron microscopy. The study of different stages of boron diffusion shows that, as in the classical model of Matthews, dislocation loops are initially generated at the epilayer surface. Subsequently the threading segments expand laterally and lay down a segment of misfit dislocation at the diffuse interface. The Burgers vector of the dislocation loop is inclined with respect to the interface and thus the initial misfit dislocations are not very efficient. However, as the diffusion proceeds, non-parallel dislocations interact and give rise to product segments that have parallel Burgers vectors. Based on the observations, a model is presented to elucidate the details of these interactions and the formation of more efficient misfit dislocations from the less-efficient inclined ones.


A type IaB diamond specimen containing partially decomposed platelets, dislocation loops and voidites has been investigated by transmission electron microscopy. The dislocation loops were found to be prismatic and interstitial in nature, some with Burgers vector ½ a <110> previously reported, but most with Burgers vector a <001>. Burgers vector analysis of the bounding dislocation of partially decomposed platelets shows that the a <001> loops are formed by transformation of the platelets, by nucleation and climb of a <00(1— f )> dislocation, combining with the a <00 f > dislocation bounding the platelet. The climb mechanism is driven by the need to generate vacancies for the decomposition of the platelets and to accommodate the nitrogen either in small clusters in solution in the lattice or in voidites. Glide dislocations interacting with the platelets are likely to act as nucleating centres for the climb process. The ½ a <110> dislocation loops are considered to be formed by dissociation of the a <001> loops, promoted by interaction with glide dislocations and involving prismatic slip and conservative climb. Voidites are assumed to originate as bubbles of fluid nitrogen formed at high pressure and temperature as a result of decomposition of the platelets; at room temperature they may be liquid or solid depending on the pressure, which cannot be estimated accurately. Electron diffraction patterns and microscope images of voidites prove that many consist of a solid phase at 300 K. It is suggested that the diamond has been subjected to a drop in pressure at high temperature, causing platelet decomposition and the generation of voidites, that may occur during ejection of the diamond to the earth’s surface.


1995 ◽  
Vol 378 ◽  
Author(s):  
K. B. Belay ◽  
D. L. Llewellyn ◽  
M. C. Ridgway

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.


1993 ◽  
Vol 321 ◽  
Author(s):  
J. W. Strane ◽  
S. T. Picraux ◽  
H. J. Stein ◽  
S. R. Lee ◽  
J. Candelaria ◽  
...  

ABSTRACTThis study investigates the stability of Metastable Si1-yCy/Si heterostructures during rapid thermal annealing (RTA) over a temperature range of 1000 – 1150° C Heterostructures of Si1-yCy/Si and Si1-x-yGexCy/Si (x=0.077, y ≤ .0014) were formed by solid phase epitaxy from C implanted, preamorphized substrates using a 30 Minute 700° C anneal in N2. The occupancy of C in substitution lattice sites was monitored by Fourier Transform Infrared Absorption spectroscopy. The layer strain was monitored by rocking curve x-ray diffraction and the structural changes in the layers were determined using plan-view and X-sectional transmission electron Microscopy (TEM). For anneals of 1150° C or above, all the substitutional C was lost from the Si lattice after 30 seconds. TEM verified that the strain relaxation was the result of C precipitating into highly aligned βSiC particles rather than by the formation of extended defects. No nucleation barrier was observed for the loss of substitutional C Preliminary results will also be discussed for Si1-x-yGexCy/Si heterostructures where there is the additional factor of the competition between strain energy and the chemical driving forces.


1982 ◽  
Vol 13 ◽  
Author(s):  
J. Narayan ◽  
O. W. Holland ◽  
G. L. Olson

ABSTRACTThe nature of residual damage in As+, Sb+, and In+ implanted silicon after CW laser and e− beam annealing has been studied using plan-view and cross-section electron microscopy. Lattice location of implanted atoms and their concentrations were determined by Rutherford backscattering and channeling techniques. Maximum substitutional concentrations achieved by furnace annealing in a temperature range of 500–600°C have been previously reported [1] and greatly exceeded the retrograde solubility limits for all dopants studied. Higher temperatures and SPE growth rates characteristic of electron or cw laser annealing did not lead to greater incorporation of dopant within the lattice and often resulted in dopant precipitation. Dopant segregation at the surface was sometimes observed at higher temperatures.


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