GISAXS study of defects in He implanted silicon (original) (raw)
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Materials Science and Engineering: B, 2000
Thermal desorption spectrometry (TDS) has been applied to investigate the thermal evolution of vacancy-like defects in helium-implanted (100) silicon samples with a dose of 2 ×10 16 cm − 2 at 20 keV. The measured spectra present features which can be interpreted as fingerprints of the modifications occurring in the sample. The defects that are recognized which affect the desorption are: thermally unstable helium-vacancy complexes, pressurized gas bubbles organized in planar structures (cracks) and thermally stable cavities. The attribution is supported by the results obtained by complementary techniques, such elastic recoil detection, channeling Rutherford backscattering spectrometry, cross sectional transmission electron microscopy and positron annihilation spectroscopy which have been employed on isothermally pre-annealed samples in the range 100 -800°C
Effect of uniform stress on silicon implanted with helium, hydrogen and oxygen
Computational Materials Science, 2001
The eect of annealing at up to 1550 K under argon pressure up to 1.5 GPa (high temperature±high pressure (HT± HP) treatment) on silicon implanted with helium, hydrogen or oxygen (Si:He, Si:H or Si:O) was investigated by X-ray, secondary ions mass spectrometry (SIMS), transmission electron microscopy (TEM), photoluminescence (PL), and electrical methods. The HT±HP treatment of Si:He results in decrease of defect concentration. The treatment at 720 K, 1.1 GPa for 10 h resulted in unchanged strain (while annealing at 720 K, 10 5 Pa ± in its marked decrease) and in enhancement of thermal donor (TD) concentration. A similar treatment of Si:H resulted in suppression of hydrogen out-diusion with its pronounced diusion into sample depth and stress-stimulated creation of small defects/TD. Generation of dislocations was strongly suppressed in the HT±HP treated Si:O samples. The observed eects were explained accounting for HP-induced suppression of helium and hydrogen out-diusion from Si:He and Si:H, and for a decrease of mis®t at the oxygen precipitate/Si boundary in Si:O.
Crystallography Reports, 2014
The structural changes in the surface layers of silicon substrates, implanted by helium ions with energies from 2 to 5 keV and doses to 6 × 10 15-5 × 10 17 cm-2 , has been studied by high resolution X ray reflectometry. The damaged layer is found to have a total thickness comparable with the total ion path length (estimated from the SRIM model) and a multilayer structure: a strongly amorphized layer with reduced den sity, a porous (incapsulated) layer, and a deformed layer. The thickness of sublayers, their density ρ(z), and the mean strain (∼5 × 10-3) have been determined. The characteristic pore size is estimated to be 5-20 nm. It is shown that the presence of a nanoporous layer facilitates the formation of diffuse scattering, which can be used to diagnose layers by high resolution X ray reflectometry.
DLTS and EPR study of defects in H implanted silicon
Nuclear Instruments and Methods in Physics Research Section B: Beam Interactions with Materials and Atoms, 2002
Single crystal CZ Si samples were implanted with hydrogen ions to the dose of 2E16 He ions/cm 2 at room temperature and subsequently annealed in vacuum in the temperature interval from 100 to 900°C. The aim of the experiment was to determine the conditions for bubble formation within the solid film, which may have important technological application. Defects produced in such samples were studied by deep-level transient spectroscopy (DLTS) and electron paramagnetic resonance (EPR) spectroscopy. It is shown that high dose hydrogen implantation produces vacancy-related and silicon selfinterstitial clusters. The latter are thought to be responsible for the formation of the weak displacement field. The annealing at higher temperatures creates multivacancy-related clusters responsible for the strong displacement field formation. Ó
X-ray scattering study of hydrogen implantation in silicon
Journal of Applied Physics, 2006
The effect of hydrogen implantation in silicon single crystals is studied using high-resolution x-ray scattering. Large strains normal to the sample surface are evidenced after implantation. A simple and direct procedure to extract the strain profile from the scattering data is described. A comparison between different crystallographic orientation of the implanted silicon surface is then presented, namely, for ⟨100⟩, ⟨110⟩, and ⟨111⟩ orientations, showing a dependence that can be related to bond orientation. Effect of annealing on the stressed structure is finally described.
Stability of cavities formed by He + implantation in silicon
Nuclear Instruments & Methods in Physics Research Section B-beam Interactions With Materials and Atoms, 1999
Microscopic cavities are known to be ecient gettering sites for metallic impurities in silicon. In the present study, they were formed in á1 1 1ñ silicon by 40 keV room temperature He implantation at doses of 5´10 16 and 10 17 /cm 2 , followed by a heat treatment in an N 2 atmosphere using either rapid thermal annealing or conventional furnace annealing. Helium desorption and cavity evolution were studied by non-Rutherford elastic scattering of protons and Rutherford backscattering/channeling analysis. Cavities and residual defects were observed by transmission electron microscopy (TEM). The retained fraction of helium was shown to depend on the manner of annealing and was found to decrease with annealing time much more slowly than the ®rst order gas release model. TEM observations show that {3 1 1} defects and dislocations are also present close to the cavities. Channeling analysis shows that {3 1 1} defects dissolve during the ®rst minutes of annealing at 800°C. It is assumed that the self-interstitials released from these defects are able to ®ll the smallest cavities, thus causing a rapid increase of the mean cavity radius. This variation, introduced in the desorption law, leads to reasonable agreement with the experimental results. For longer annealing time the total cavity surface decreases slowly with annealing duration. Ó
Solid State Phenomena, 2008
Transmission electron microscopy (TEM) and scanning electron microscopy (SEM) have been used to compare hydrogen defects formed in p doped [001] oriented Cz silicon samples which are H + plasma treated , H + implanted or Si + implanted + H + plasma treated. Samples were studied as processed and after annealing at 250°C, 450°C and 600°C. It is found that 1 hour H + plasma treatment at 250°C produces a low density of large defects (~100 nm) in prefered {111} plans close to the surface. H + implantation at a dose of 3x10 16 cm -2 produces high density of small (~ 20 nm) mostly {100} platelets that after 1 hour annealing at 450°C result in microcrack formation. Lower H + implantation doses form very few microcracks at this temperature. Silicon implantation with a dose of 10 15 cm 2 followed by 1 hour H + plasma treatment at 250°C and 1 hour annealing at 450°C produces similar microstructure and microcracks as the 3x10 16 cm 2 H + implantation dose. Solid State Phenomena Vols. 131-133 (2008) pp. 309-314 online at http://www.scientific.net
Solid State Phenomena, 2008
Transmission electron microscopy (TEM) and scanning electron microscopy (SEM) have been used to compare hydrogen defects formed in p doped [001] oriented Cz silicon samples which are H + plasma treated , H + implanted or Si + implanted + H + plasma treated. Samples were studied as processed and after annealing at 250°C, 450°C and 600°C. It is found that 1 hour H + plasma treatment at 250°C produces a low density of large defects (~100 nm) in prefered {111} plans close to the surface. H + implantation at a dose of 3x10 16 cm-2 produces high density of small (~ 20 nm) mostly {100} platelets that after 1 hour annealing at 450°C result in microcrack formation. Lower H + implantation doses form very few microcracks at this temperature. Silicon implantation with a dose of 10 15 cm 2 followed by 1 hour H + plasma treatment at 250°C and 1 hour annealing at 450°C produces similar microstructure and microcracks as the 3x10 16 cm 2 H + implantation dose.
Crystallography Reports, 2013
The influence of the implantation of silicon single crystals by fluorine, nitrogen, oxygen, and neon ions on the distribution of strain and the static Debye-Waller factor in the crystal lattice over the implanted layer depth has been investigated by high resolution X ray diffraction. The density depth distribution in the surface layer of native oxide has been measured by X ray reflectometry. Room temperature implantation conditions have ensured the equality of the suggested ranges of ions of different masses and the energies trans ferred by them to the target. It is convincingly shown that the change in the structural parameters of the radi ation damaged silicon layer and the native oxide layer depend on the chemical activity of the implanted ions.