Residual Damage in Heavily Germanium-Doped Silicon

1992 ◽  
Vol 279 ◽  
Author(s):  
Esin Demirlioğlu ◽  
Sheldon Aronowitz ◽  
David Su
Keyword(s):  
Low Dose ◽  
Single Crystal Silicon ◽  
Crystal Silicon ◽  
Cross Sectional ◽  
Implantation Energy ◽  
Damage Layer ◽  
Transmission Electron ◽  
Boron Implantation ◽  
Residual Damage ◽  
High Doses

ABSTRACTCross-sectional transmission electron microscopy (XTEM) studies have shown that two distinct damage regions are created when germanium is implanted into single-crystal silicon in high doses and subsequently annealed at high temperatures. The first layer extends approximately 90–95 nm into silicon for an implant energy of 120 keV. The second region is an end-of-range damage region located 200 nm from the silicon surface for the same implantation energy. Neither low-dose, low-energy boron implantation nor the type of cap layers used during annealing alter the damage pattern. Although the dose of the Ge implants is the major factor in the formation of the continuous damage layer, high oxygen concentration at the surface may also contribute to this effect.

Single Crystal Silicon Carbide On Silicon Using A Supersonic Gas Jet Of Methylsilane

1997 ◽  
Vol 483 ◽  
Author(s):  
S. A. Ustin ◽  
C. Long ◽  
L. Lauhon ◽  
W. Ho
Keyword(s):  
Growth Rate ◽  
Growth Rates ◽  
Single Crystal Silicon ◽  
Maximum Growth ◽  
X Ray Diffraction ◽  
Crystal Silicon ◽  
Cross Sectional ◽  
Supersonic Molecular Beam ◽  
Transmission Electron

AbstractCubic SiC films have been grown on Si(001) and Si(111) substrates at temperatures between 600 °C and 900 °C with a single supersonic molecular beam source. Methylsilane (H3SiCH3) was used as the sole precursor with hydrogen and nitrogen as seeding gases. Optical reflectance was used to monitor in situ growth rate and macroscopic roughness. The growth rate of SiC was found to depend strongly on substrate orientation, methylsilane kinetic energy, and growth temperature. Growth rates were 1.5 to 2 times greater on Si(111) than on Si(001). The maximum growth rates achieved were 0.63 μm/hr on Si(111) and 0.375μm/hr on Si(001). Transmission electron diffraction (TED) and x-ray diffraction (XRD) were used for structural characterization. In-plane azimuthal (ø-) scans show that films on Si(001) have the correct 4-fold symmetry and that films on Si(111) have a 6-fold symmetry. The 6-fold symmetry indicates that stacking has occurred in two different sequences and double positioning boundaries have been formed. The minimum rocking curve width for SiC on Si(001) and Si(111) is 1.2°. Fourier Transform Infrared (FTIR) absorption was performed to discern the chemical bonding. Cross Sectional Transmission Electron Microscopy (XTEM) was used to image the SiC/Si interface.

A study of 2 MeV oxygen implantation to form deeply buried SiO2 layers

1989 ◽  
Vol 4 (5) ◽  
pp. 1227-1232 ◽  
Author(s):  
J. J. Grob ◽  
A. Grob ◽  
P. Thevenin ◽  
P. Siffert ◽  
C. d'Anterroches ◽  
...  
Keyword(s):  
Single Crystal ◽  
Single Crystal Silicon ◽  
Single Step ◽  
Annealing Process ◽  
Dislocation Network ◽  
Crystal Silicon ◽  
Cross Sectional ◽  
Transmission Electron ◽  
Distribution Moments ◽  
Best Fit

Oxygen ions were implanted into (100) oriented single crystal Si at energies in the range of 0.6 to 2 MeV at normal and oblique (60°) incidences. Oxygen concentration profiles were measured using the 16O(d, α)14N nuclear reaction for 900 keV deuterons. The experimentally measured oxygen distributions were subsequently fitted to the theoretical profiles calculated assuming the Pearson VI distribution. The distribution moments (Rp, ΔRp, ΔR⊥ skewness, and kurtosis) were deduced as the best fit parameters and compared to the computer simulation results (TRIM 87 and PRAL). Whatever the calculation method, the measured Rp and ΔRp values are close to those predicted by the theory. Deeply buried SiO2 layers were formed using a single step implantation and annealing process. A dose of 1.8 × 1018/cm2 of 2 MeV O+ was implanted into the Si substrate maintained at a temperature of 550 °C. The implanted samples were characterized using the Rutherford backscattering (RBS)/channeling technique and cross-sectional transmission electron microscopy (XTEM). The implanted samples were subsequently annealed at 1350 °C for 4 h in an Ar ambient. The annealing process results in creating a continuous SiO2 layer, 0.4 μm thick below a 1.6 μm thick top single crystal silicon overlayer. The buried SiO2 layer contains the well-known faceted Si inclusions. The density of dislocations within the top Si layer remains lower than the XTEM detection limit of 107/cm2. Between the Si overlayer and the buried SiO2 a layer of faceted longitudinal SiO2 precipitates is present. A localized dislocation network links the precipitates to the buried SiO2 layer.

Temperature Dependence of Damage in Boron-Implanted Silicon

1989 ◽  
Vol 147 ◽  
Author(s):  
G. Ottaviani ◽  
F. Nava ◽  
R. Tonini ◽  
S. Frabboni ◽  
G. F. Cerofolini ◽  
...  
Keyword(s):  
Room Temperature ◽  
Amorphous Layer ◽  
Systematic Investigation ◽  
Vacuum Furnace ◽  
Cross Sectional ◽  
Ion Channeling ◽  
Projected Range ◽  
Transmission Electron ◽  
Boron Implantation ◽  
Residual Damage

AbstractWe have performed a systematic investigation of boron implantation at 30 keV into <100> n-type silicon in the 77 –300 K temperature range and mostly at 9×1015 cm−2 fluence. The analyses have been performed with ion channeling and cross sectional transmission electron microscopy both in as-implanted samples and in samples annealed in vacuum furnace at 500 °C and 850 °C for 30 min. We confirm the impossibility of amorphization at room temperature and the presence of residual damage mainly located at the boron projected range. On the contrary, a continuous amorphous layer can be obtained for implants at 77 K and 193 K; the thickness of the implanted layer is increased by lowering the temperature, at the same time the amorphous-crystalline interface becomes sharper. Sheet resistance measurements performed after isochronal annealing shows an apparent reverse annealing of the dopant only in the sample implanted at 273 K. The striking differences between light and heavy ions observed at room temperature implantation disappears at 77 K and full recovery with no residual damage of the amorphous layer is observed.

Microwave Activation of Dopants & Solid Phase Epitaxy in Silicon

2007 ◽  
Vol 989 ◽  
Author(s):  
Douglas C. Thompson ◽  
J. Decker ◽  
T. L. Alford ◽  
J. W. Mayer ◽  
N. David Theodore
Keyword(s):  
Single Crystal ◽  
Microwave Heating ◽  
Rutherford Backscattering Spectrometry ◽  
Solid Phase ◽  
Single Crystal Silicon ◽  
Silicon Substrates ◽  
Crystal Silicon ◽  
Cross Sectional ◽  
Transmission Electron ◽  
Microwave System

AbstractMicrowave heating is used to activate solid phase epitaxial re-growth of amorphous silicon layers on single crystal silicon substrates. Layers of single crystal silicon were made amorphous through ion implantation with varying doses of boron or arsenic. Microwave processing occurred inside a 2.45 GHz, 1300 W cavity applicator microwave system for time-durations of 1-120 minutes. Sample temperatures were monitored using optical pyrometery. Rutherford backscattering spectrometry, and cross-sectional transmission electron microscopy were used to monitor crystalline quality in as-implanted and annealed samples. Sheet resistance readings show dopant activation occurring in both boron and arsenic implanted samples. In samples with large doses of arsenic, the defects resulting from vacancies and/or micro cluster precipitates are seen in transmission electron micrographs. Materials properties are used to explain microwave heating of silicon and demonstrate that the damage created in the implantation process serves to enhance microwave absorption.

Tem Study of Porous Silicon Fabricated from N- and P-Type Doped Polycrystalline Films

1996 ◽  
Vol 452 ◽  
Author(s):  
L. Haji ◽  
Y. Le Thomas ◽  
F. Chane Che Lai ◽  
P. Joubert
Keyword(s):  
Porous Silicon ◽  
Pore Formation ◽  
Single Crystal Silicon ◽  
Extended Defects ◽  
Crystal Silicon ◽  
Cross Sectional ◽  
Si Substrates ◽  
Transmission Electron ◽  
Polycrystalline Silicon Films ◽  
P Type

AbstractThe formation of porous silicon (PS) from n/p, n+/p and p+/n structures carried from polycrystalline silicon films (poly-Si) deposited on single crystal silicon (c-Si) substrates was studied by cross-sectional transmission electron microscopy. Our results clearly show that the pore formation in such structures involve the extended defects of the poly-Si film. The role played by these defects depends on the doping type and level, and on whether the anodization is performed under illumination or not.

TEM characterization of Au/Polysilicon interactions

1990 ◽  
Vol 48 (4) ◽  
pp. 650-651
Author(s):  
N. David Theodore ◽  
Leslie H. Allen ◽  
C. Barry Carter ◽  
James W. Mayer
Keyword(s):  
Solid Phase ◽  
Single Crystal Silicon ◽  
Chemical Vapor ◽  
Electrical Contacts ◽  
Silicon Substrates ◽  
Crystal Silicon ◽  
Transmission Electron ◽  
Polysilicon Films ◽  
The Stability

Metal/polysilicon investigations contribute to an understanding of issues relevant to the stability of electrical contacts in semiconductor devices. These investigations also contribute to an understanding of Si lateral solid-phase epitactic growth. Metals such as Au, Al and Ag form eutectics with Si. reactions in these metal/polysilicon systems lead to the formation of large-grain silicon. Of these systems, the Al/polysilicon system has been most extensively studied. In this study, the behavior upon thermal annealing of Au/polysilicon bilayers is investigated using cross-section transmission electron microscopy (XTEM). The unique feature of this system is that silicon grain-growth occurs at particularly low temperatures ∽300°C).Gold/polysilicon bilayers were fabricated on thermally oxidized single-crystal silicon substrates. Lowpressure chemical vapor deposition (LPCVD) at 620°C was used to obtain 100 to 400 nm polysilicon films. The surface of the polysilicon was cleaned with a buffered hydrofluoric acid solution. Gold was then thermally evaporated onto the samples.

Formation of Oxide Layers by High Dose Implantation into Silicon

1983 ◽  
Vol 27 ◽  
Author(s):  
S.S. Gill ◽  
I. H. Wilson
Keyword(s):  
Oxide Layer ◽  
Single Crystal Silicon ◽  
High Dose ◽  
Surface Oxide Layer ◽  
Crystal Silicon ◽  
Implantation Energy ◽  
Oxygen Ions ◽  
Oxygen Profile ◽  
Dose Levels ◽  
Very High

ABSTRACTSingle crystal silicon was implanted with 80, 120, 160 and 240 keV oxygen ions. Rutherford backscattering (RBS) analysis was used to obtain the implanted oxygen profile and the oxygen to silicon ratio in the implanted layer for doses in the range 1016 to 1.5 × 1018 O2+ cm−2 for room temperature implants. The depth and the thickness of the buried oxide layer has been measured as a function of implantation energy and oxygen dose. Chemical formation of stoichiometric SiO2 was confirmed by infra-red (IR) spectroscopy. Both RBS and IR indicate that once a surface oxide layer is formed for very high dose levels, the layer thickness decreases with increasing implanted dose beyond a critical dose level.

Antioxidant Status of Patients on Peritoneal Dialysis: Associations with Inflammation and Glycoxidative Stress

2009 ◽  
Vol 29 (1) ◽  
pp. 89-101 ◽  
Author(s):  
Isabella Sundl ◽  
Johannes M. Roob ◽  
Andreas Meinitzer ◽  
Beate Tiran ◽  
Gholamali Khoschsorur ◽  
...  
Keyword(s):  
Peritoneal Dialysis ◽  
Vitamin C ◽  
Interleukin 6 ◽  
Antioxidant Status ◽  
Low Dose ◽  
Cross Sectional Study ◽  
Cross Sectional ◽  
Chronic Inflammatory Response ◽  
Plasma Ascorbate ◽  
High Doses

Background Patients on peritoneal dialysis (PD) frequently exhibit oxidant–antioxidant imbalance, advanced glycation end-product overload, and subclinical inflammation but the interrelations between these pathophysiological changes have not been fully elucidated. Subjects and Methods To study possible associations, a cross-sectional study of antioxidant status, glycoxidative stress, and inflammation, using HPLC and ELISA methods, was undertaken in 37 PD patients and age- and sex-matched healthy controls. Results Plasma ascorbate concentrations were low in patients not taking at least low-dose vitamin C supplements. In patients taking vitamin C supplements, there was a positive relation between ascorbate and pentosidine concentrations. Vitamin E and carotenoid concentrations were comparable between patients and controls, while lycopene and lutein/zeaxanthin concentrations were lower. Interleukin-6, C-reactive protein (CRP), and pentosidine concentrations were elevated in PD patients. β–Cryptoxanthin, lycopene, and lutein/zeaxanthin concentrations were inversely related to interleukin-6 concentrations. β–Cryptoxanthin concentrations were also inversely related to CRP concentrations. Pentosidine showed a low dialysate-to-plasma ratio, indicating low peritoneal clearance. Pentosidine concentrations increased with duration of PD therapy, while α– and β–carotene concentrations decreased. Malondialdehyde concentrations were elevated compared to controls but remained within the normal range. Retinol concentrations decreased with PD therapy and were inversely related to interleukin-6 and CRP concentrations. Conclusions Low-dose vitamin C supplements and a carotenoid-rich diet should be recommended for PD patients to maintain normal antioxidant status and efficiently counteract the chronic inflammatory response, rather than high doses of vitamin C, which could play a role as a precursor of pentosidine.

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