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.

Absorption coefficient of Dupont Teflon FEP in the 20–130 wave-number range

1985 ◽  
Vol 24 (17) ◽  
pp. 2746 ◽  
Author(s):  
Mark A. Ordal ◽  
Robert J. Bell ◽  
Ralph W. Alexander ◽  
Raymond E. Paul
Keyword(s):  
Absorption Coefficient ◽  
Wave Number ◽  
Number Range ◽  
Wave Number Range

Phase Formation Between Codeposited Co-Ta Thin Film and Single Crystal Silicon Substrate

1995 ◽  
Vol 402 ◽  
Author(s):  
G. Riskin ◽  
J. Pelleg ◽  
M. Talianker
Keyword(s):  
Single Crystal Silicon ◽  
Vlsi Circuits ◽  
Silicon Substrates ◽  
Crystal Silicon ◽  
Temperature Range ◽  
Transmission Electron ◽  
Metal Silicides ◽  
Single Crystal Silicon Substrate ◽  
Lower Temperature Range ◽  
Lower Temperature

AbstractA combination of near-noble and refractory metal silicides was considered for shallow contacts to silicon in VLSI circuits [1]. The objective of the present work is to investigate formation of phases between codeposited Co-Ta film, of 150 nm thickness, and n-type silicon substrates of (100) or (111) orientation. Characterization of the specimens annealed in the temperature range of 600–1100°C was done by X-ray diffraction (XRD) and transmission electron microscopy (TEM). It was found that in addition to the silicide phases of Co and Ta, the intermetallic compound Co2 Ta was also formed. Co2 Ta appears only in the lower temperature range of about 600–800°C. At temperatures of 900–1100°C only the silicon rich phases were present. These are the low resistivity phases useful for devices. No ternary phases have been observed. Silicide formation occurs at a faster rate on (111) oriented silicon substrates.

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.

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.

Universality hypothesis for the small wave-number range of decaying turbulence

1995 ◽  
Vol 45 (6) ◽  
pp. 517-520
Author(s):  
L. Ts. Adzhemyan ◽  
M. Hnatich ◽  
M. Stehlik
Keyword(s):  
Wave Number ◽  
Number Range ◽  
Wave Number Range ◽  
Small Wave ◽  
Small Wave Number ◽  
Decaying Turbulence

Inviscid instability of an unbounded heterogeneous shear layer

1971 ◽  
Vol 48 (2) ◽  
pp. 405-415 ◽  
Author(s):  
S. A. Maslowe ◽  
R. E. Kelly
Keyword(s):  
Growth Rate ◽  
Froude Number ◽  
Mixing Layer ◽  
Density Variation ◽  
Wave Number ◽  
Unstable Wave ◽  
Number Range ◽  
Spatial Growth ◽  
Wave Number Range ◽  
Low Froude Number

Stability curves are computed for both spatially and temporally growing disturbances in a stratified mixing layer between two uniform streams. The low Froude number limit, in which the effects of buoyancy predominate, and the high Froude number limit, in which the effects of density variation are manifested by the inertial terms of the vorticity equation, are considered as limiting cases. For the buoyant case, although the spatial growth rates can be predicted reasonably well by suitable use of the results for temporal growth, spatially growing disturbances appear to have high group velocities near the lower cutoff wave-number. For the inertial case, it is demonstrated that density variations can be destabilizing. More precisely, when the stream with the higher velocity has the lower density, both the wave-number range of unstable disturbances and the maximum spatial growth rate are increased relative to the case of homogeneous flow. Finally, it is shown how the growth rate of the most unstable wave in the inertial case diminishes as buoyancy becomes important.

Pulsed Ion-Beam Induced Reactions of Ni And Co With Amorphous and Single Crystal Silicon

1984 ◽  
Vol 35 ◽  
Author(s):  
J. O. Olowolafe ◽  
R. Fastow
Keyword(s):  
Amorphous Silicon ◽  
Ion Beam ◽  
Single Crystal Silicon ◽  
Reaction Rates ◽  
Rutherford Backscattering ◽  
Thin Layers ◽  
X Ray Diffraction ◽  
Furnace Annealing ◽  
Crystal Silicon ◽  
Transmission Electron

ABSTRACTThin layers (~1,000 A ) of Ni and Co have been reacted with both (100) and amorphous silicon (a-Si) using a pulsed ion beam. Samples were analyzed using Rutherford backscattering, x-ray diffraction, and transmission electron microscopy. Rutherford backscattering showed that the metal/a-Si and metal/(100)-Si reaction rates were comparable. Both reactions began at the composition of the lowest eutectic. For comparison. furnace annealing of the same structures showed that the reaction rate of Ni with amorphous silicon was greater than with (100) Si; Co reacted nearly identically with both substrates. Diffraction data suggest that pulsed ion beam annealing crystallizes the amorphous silicon before the metal/a-Si reaction begins.

Sign in / Sign up

Export Citation Format

Share Document