Variations in the Refractive Index of the Near-Surface Region of Low Energy Hydrogen Ion Bombarded Silicon

1985 ◽  
Vol 59 ◽  
Author(s):  
R. B. Pettit ◽  
J. K. G. Panitz
Keyword(s):  
Refractive Index ◽  
Single Crystal Silicon ◽  
Surface Region ◽  
Incident Radiation ◽  
Ion Source ◽  
Index Of Refraction ◽  
Hydrogen Ion ◽  
Crystal Silicon ◽  
Near Surface ◽  
Hydrogen Beam

ABSTRACTUsing ellipsometric analysis, the complex index of refraction of lowenergy, hydrogen ion bombarded, [100] single-crystal silicon was measured as a function of distance from the bombarded surface. The bombardment conditions were a 1600 eV hydrogen beam produced by a Kaufman ion source, 1.4 mA/cm2 flux, 2 × 1018 ions/cm2 fluence and 275°C bulk silicon temperature. These conditions are comparable to the conditions generally reported to result in a substantial increase in the electrical conductivity of polycrystalline silicon solar cell material. The results of this study indicate that the real and imaginary parts of the refractive index of the ion bombarded surface region approach that of the unbombarded substrate at a depth of 50 nm. The refractive index of about the first 10 nm of ion bombarded material is strongly dependent on the bombardment conditions. Variations in the imaginary part of the refractive index indicate that approximately 10% of incident radiation is absorbed by the first 50 nm of modified material.

Growth Mechanism of Hydrogen Clusters

1997 ◽  
Vol 467 ◽  
Author(s):  
N. H. Nickel ◽  
G. B. Anderson ◽  
N. M. Johnson ◽  
J. Walker
Keyword(s):  
Fermi Level ◽  
Single Crystal ◽  
Growth Mechanism ◽  
Polycrystalline Silicon ◽  
Single Crystal Silicon ◽  
Surface Region ◽  
Crystal Silicon ◽  
Hydrogen Clusters ◽  
Near Surface ◽  
Crystallographic Planes

ABSTRACTIt is demonstrated that the exposure of polycrystalline silicon (poly-Si) to monatomic hydrogen results in the formation of H clusters. These H stabilized platelets appear in the near-surface region ( 100 nm) and are predominantly oriented along {111} crystallographic planes. Platelet concentrations of ≈5×1015, 1.5×1016-cm−3, and 2.4×1017 cm−3 were observed in nominally undoped poly-Si, phosphorous doped poly-Si (P=1017 cm−3), and phosphorous doped single crystal silicon (P>3×1018 cm−3), respectively. Results obtained on doped c-Si demonstrate that platelet generation occurs only at Fermi-level positions of Ec -EF < 0.4 eV.

scholarly journals Анодное окисление слоев кремний-на-изоляторе, созданных методом водородного переноса

2019 ◽  
Vol 53 (2) ◽  
pp. 253
Author(s):  
И.Е. Тысченко ◽  
И.В. Попов ◽  
Е.В. Спесивцев
Keyword(s):  
Oxidation Rate ◽  
Hydrogen Transfer ◽  
Single Crystal Silicon ◽  
Interatomic Interaction ◽  
Surface Region ◽  
Bound State ◽  
Silicon On Insulator ◽  
Bulk Single Crystal ◽  
Crystal Silicon ◽  
Insulator Layer

AbstractThe anodic oxidation rate of silicon-on-insulator films fabricated by hydrogen transfer is studied as a function of the temperature of subsequent annealing. It is established that the oxidation rate of transferred silicon-on-insulator films is five times lower compared to the oxidation rate of bulk single-crystal silicon samples. The oxidation rate increases, as the annealing temperature is elevated in the range 700–1100°C and as the depth of gradually removed anode-oxidized layers is increased. The results obtained in the study are attributed to an increase in the efficiencies of the anodic current and oxygen–silicon interatomic interaction due to the annealing of defects and due to release of hydrogen from the bound state, respectively. The formation of hydrogen bubbles in the surface region of silicon due to the diffusion of hydrogen, released in the process of the oxidation reaction, towards micropores in the silicon-on-insulator layer is detected.

Ion Implantation of Ti INTO LiNbO3: Fabrication of Waveguides and Simple Modulators

1989 ◽  
Vol 152 ◽  
Author(s):  
C. W. White ◽  
D. K. Thomas ◽  
P. R. Ashley ◽  
W. S. C. Chang ◽  
C. Buchal
Keyword(s):  
Ion Implantation ◽  
Solid Phase ◽  
Surface Region ◽  
Amorphous Region ◽  
Index Of Refraction ◽  
Near Surface ◽  
Channel Waveguides ◽  
High Doses ◽  
Water Saturated ◽  
Saturated Oxygen

ABSTRACTIon implantation has been used to introduce Ti at very high doses (>3 × 1017 /cm2) into the near-surface region of LiNbO3 to change the index of refraction.’ In the as-implanted state, the near surface is amorphous. Thermal annealing in water-saturated oxygen 1000°C crystallizes the amorphous region and incorporates the Ti into substitutional sites in the lattice at concentrations that exceed 10 at.%. Recrystallization takes place by solid-phase epitaxy. Both planar and channel waveguides have been fabricated with optical attenuations of <1 dB/cm. Both Mach-Zehnder and Bragg modulators have been fabricated using Ti implantation of LiNbO3. The characteristics of these devices have been determined and will be reported. The higher Ti concentrations which can be achieved by implantation allows tighter mode confinement and smaller mode profiles than with Ti-diffused guides.

Far-infrared properties of helium-doped silicon

2015 ◽  
Vol 93 (8) ◽  
pp. 935-940
Author(s):  
Wei Ren ◽  
Qingyan Zhou ◽  
Bing Li ◽  
Hongxiang Deng ◽  
Shaobo Han ◽  
...  
Keyword(s):  
Refractive Index ◽  
Absorption Coefficient ◽  
Single Crystal Silicon ◽  
Far Infrared ◽  
Wave Number ◽  
Crystal Silicon ◽  
Number Range ◽  
Temperature Range ◽  
Transmission Electron ◽  
Wave Number Range

Single crystal silicon is an important material used for semiconductor devices and also a potential material in device research. Far-infrared optical properties are studied for the helium ion implanted samples with different fluences of 5.0 × 1016, 1.0 × 1017, 2.0 × 1017, and 4.0 × 1017 cm−2. The absorption coefficient and refractive index of silicon with different helium concentrations are measured in the wave number range from 4 to 85 cm−1 and temperature range from 145 to 520 K. The results show that the absorption coefficient increases with increasing fluence of helium ions, but the refractive index decreases. The correlations between absorption coefficient and refractive index and temperature of all samples are similar. The refractive index increases with temperature in the whole measurement temperature range, but the absorption coefficient has different trends in the different wavebands. The absorption coefficient decreases with the increase of temperature in the region below 12 cm−1; however, the absorption coefficient increases when the wave number is larger than 30 cm−1. The absorption coefficient curves at different wavebands are well fitted by the Drude model. A large number of helium bubbles and defects, such as voids and dislocations have been observed in the implanted area by transmission electron microscopy (TEM), which contributes to the increase of optical absorption.

Infrared and Ion Beam Analysis of SIxN1−x Alloys Grown by Ion Beam Assisted Deposition

1986 ◽  
Vol 71 ◽  
Author(s):  
E.P. Donovan ◽  
D.R. Brighton ◽  
D. Van Vechten ◽  
G.K. Hubler
Keyword(s):  
Nitrogen Content ◽  
Ion Beam ◽  
Single Crystal Silicon ◽  
Front Surface ◽  
Index Of Refraction ◽  
Reflection Spectra ◽  
Crystal Silicon ◽  
Ion Beam Assisted Deposition ◽  
Nitrogen Ion ◽  
Film Substrate

AbstractThin films of amorphous SixNl-x alloys were produced by nitrogen ion beam assisted deposition of electron beam evaporated silicon. Infrared reflection spectra were measured in the range 600 to 10000 cm−1. Fringes were observed due to interference between light multiply-reflected from the front surface and film-substrate (single crystal silicon) interface. Similar measurements were performed on films crystallized by post-deposition furnace anneals. Analyses of the reflection spectra were used to obtain refractive index profiles. Profiles were correlated with nitrogen content as measured by Rutherford BackscatterLng Spectometry (RBS) and Auger Electron Spectroscopy (AES). Film adhesion, density, and purity were found to be improved for depositions assisted by nitrogen ion beams (1000 to 25,000 eV) relative to unassisted evaporation, and the index of refraction decreases monotonically with increasing nitrogen content.

scholarly journals Исследование морфологии поверхности и химического состава кремния, имплантированного ионами меди

2020 ◽  
Vol 90 (10) ◽  
pp. 1715
Author(s):  
В.В. Воробьев ◽  
А.И. Гумаров ◽  
Л.Р. Тагиров ◽  
А.М. Рогов ◽  
В.И. Нуждин ◽  
...  
Keyword(s):  
Surface Layer ◽  
Ion Beam ◽  
Single Crystal Silicon ◽  
Implantation Dose ◽  
Crystal Silicon ◽  
Copper Silicide ◽  
Near Surface ◽  
Si Substrates ◽  
Average Size ◽  
Cu Ions

This paper presents the results of studies of the structure and chemical composition of the surface of single-crystal silicon c-Si substrates implanted with Cu^+ ions with an energy of 40 keV and doses in the range of 3.1 · 10^15 - 1.25 · 10^17 ions/cm^2 at a current density in the ion beam of 8 μA/cm^2. Using scanning electron and probe microscopy in combination with X-ray photoelectron and Auger electron spectroscopy it was found that at the initial stage of irradiation with Cu^+ ions up to a dose of 6.25 · 10^16 ions/cm^2 Cu metal nanoparticles with an average size of 10 nm are formed in the surface layer of Si. With a further increase in the implantation dose starting from a value of 1.25 · 10^17 ions/cm^2 and higher the η-phase of copper silicide η-Cu3Si nucleates. This circumstance is due to the heating of the near-surface layer of Si substrate during its irradiation to a temperature conducive to the phase formation of η-Cu3Si.

HREM observation of dislocations near room temperature fractures in silicon

1988 ◽  
Vol 46 ◽  
pp. 892-893
Author(s):  
M. H. Rhee ◽  
W. A. Coghlan
Keyword(s):  
Cross Section ◽  
Room Temperature ◽  
Single Crystal Silicon ◽  
Dislocation Nucleation ◽  
Back Side ◽  
Ion Milling ◽  
Crystal Silicon ◽  
Flat Surfaces ◽  
Induced Fractures ◽  
Vicker’S Microhardness

Silicon is believed to be an almost perfectly brittle material with cleavage occurring on {111} planes. In such a material at room temperature cleavage is expected to occur prior to any dislocation nucleation. This behavior suggests that cleavage fracture may be used to produce usable flat surfaces. Attempts to show this have failed. Such fractures produced in semiconductor silicon tend to occur on planes of variable orientation resulting in surfaces with a poor surface finish. In order to learn more about the mechanisms involved in fracture of silicon we began a HREM study of hardness indent induced fractures in thin samples of oxidized silicon.Samples of single crystal silicon were oxidized in air for 100 hours at 1000°C. Two pieces of this material were glued together and 500 μm thick cross-section samples were cut from the combined piece. The cross-section samples were indented using a Vicker's microhardness tester to produce cracks. The cracks in the samples were preserved by thinning from the back side using a combination of mechanical grinding and ion milling.

Preparation of cross-sectional samples for near-surface TEM studies

1987 ◽  
Vol 45 ◽  
pp. 380-381
Author(s):  
R.C. Dickenson ◽  
K.R. Lawless
Keyword(s):  
Standard Sample ◽  
Surface Region ◽  
Specimen Preparation ◽  
Thick Sheet ◽  
Drill Bit ◽  
Sample Holder ◽  
Metal Interface ◽  
Cross Sectional ◽  
Near Surface ◽  
Cold Worked

In thermal oxidation studies, the structure of the oxide-metal interface and the near-surface region is of great importance. A technique has been developed for constructing cross-sectional samples of oxidized aluminum alloys, which reveal these regions. The specimen preparation procedure is as follows: An ultra-sonic drill is used to cut a 3mm diameter disc from a 1.0mm thick sheet of the material. The disc is mounted on a brass block with low-melting wax, and a 1.0mm hole is drilled in the disc using a #60 drill bit. The drill is positioned so that the edge of the hole is tangent to the center of the disc (Fig. 1) . The disc is removed from the mount and cleaned with acetone to remove any traces of wax. To remove the cold-worked layer from the surface of the hole, the disc is placed in a standard sample holder for a Tenupol electropolisher so that the hole is in the center of the area to be polished.

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