Theory of Hydrogen Complexes in Si

1990 ◽  
Vol 209 ◽  
Author(s):  
S. B. Zhang ◽  
W. B. Jackson
Keyword(s):  
Binding Energy ◽  
Raman Spectra ◽  
Experimental Results ◽  
Lattice Expansion ◽  
Strained Si ◽  
Amorphous Si ◽  
Gap States ◽  
Hydrogenated Amorphous ◽  
And Diffusion ◽  
Strained Bonds

ABSTRACTThe predominance of Si-H bonding and the origin of {111} platelets in hydrogenated Si remain important unsolvedproblems in the study of H in Si.Recent theoretical and experimental results indicate that H predominately enters the Si network in pairs. A promising diatomic H configuration consists of a bond centered H closely associated with an antibonding centered H. In this work, we show that adjacent diatomic H pairs have a binding energy of 0.2 eV/2H. The binding originates from relaxation of strained Si-Si backbonds. Further clustering of the H pairs eliminates all strained bonds, forming a hydrogenated platelet oriented along the {111} plane. The binding energy of 3.95 eV/2H for the platelet is 0.15 eV lower than that for interstitial H2 molecules in c-Si. Lattice expansion makes the platelets energetically more competitivewith the lowest energy Si-H bonding confi gration at hydrogenated Si (111) surfaces. These higher level complexes explainthe formation of platelets, Raman spectra, and absence of gap states in hydrogenated c- Si as well as the clustered phaseseen in NMR and of H evolution and diffusion in hydrogenated amorphous Si.

Theory and Simulation of Dopant Diffusion in SiGe

2003 ◽  
Vol 765 ◽  
Author(s):  
Chun-Li Liu ◽  
Marius Orlowski ◽  
Aaron Thean ◽  
Alex Barr ◽  
Ted White ◽  
...  
Keyword(s):  
Volume Change ◽  
Defect Formation ◽  
Formation Enthalpy ◽  
Lattice Expansion ◽  
Strained Si ◽  
P Diffusion ◽  
Expansion Theory ◽  
The Difference ◽  
And Diffusion ◽  
Good Agreement

AbstractStrained Si-based technology has imposed a new challenge for understanding dopant implantation and diffusion in SiGe that is often used as the buffer layer for a strained Si cap layer. In this work, we describe our latest modeling effort investigating the difference in dopant implantation and diffusion between Si and SiGe. A lattice expansion theory was developed to account for the volume change due to Ge in Si and its effect on defect formation enthalpy. The theory predicts that As diffusion in SiGe is enhanced by a factor of ∼10, P diffusion by a factor of ∼2, and B diffusion is retarded by a factor of ∼6, when compared to bulk Si. These predictions are consistent with experiment. Dopant profiles for As, P, and B were simulated using process simulators FLOOPS and DIOS. The simulated profiles are in good agreement with experiment.

Electric field effect in amorphous semiconductor films assembled from transition-metal-encapsulating Si clusters

2011 ◽  
Vol 1321 ◽  
Author(s):  
N. Uchida ◽  
T. Miyazaki ◽  
Y. Matsushita ◽  
K. Sameshima ◽  
T. Kanayama
Keyword(s):  
Electric Field ◽  
Field Effect ◽  
Amorphous Semiconductor ◽  
Electric Field Effect ◽  
Semiconductor Films ◽  
Spin Resonance ◽  
Solid Substrates ◽  
Amorphous Si ◽  
Gap States ◽  
Hydrogenated Amorphous

ABSTRACTWe synthesized amorphous semiconductor films composed of Mo-encapsulating Si clusters (MoSin : n∼10) on solid substrates. The MoSi10 films had Si networks similar to hydrogenated amorphous Si and an optical gap of 1.5 eV. Electron spin resonance signals were not observed in the films indicating that dangling bonds of Si were terminated by Mo atoms. We fabricated thin-film-transistors using the MoSi10 film as a channel material. The electric field effect of the film was clearly observed. This suggests that the density of mid-gap states in the film is low enough for the field effect to occur.

Recovery Kinetics of Phosphorus Ion-Implanted a-Si:H

1996 ◽  
Vol 420 ◽  
Author(s):  
J. Nakata ◽  
S. Wagner ◽  
H. Gleskova ◽  
P. A. Stolk ◽  
J. M. Poate
Keyword(s):  
Gas Phase ◽  
Thermal Activation ◽  
Urbach Energy ◽  
Defect Density ◽  
Strained Si ◽  
Effective Electron ◽  
Additional Illumination ◽  
Hydrogenated Amorphous ◽  
Kinetics Of ◽  
Strained Bonds

AbstractHydrogenated amorphous silicon was implanted with phosphorus ions to a uniform concentration of 3×1020 cm-3 and defect saturation. The implants were annealed isochronally up to 400°C in the dark or under additional illumination. This illumination had no effect on recovery. The Urbach energy remains higher than that of silicon-implants. The midgap defect density anneals to ˜ 1018 cm-3, typical of gas-phase doped samples. The dark conductvity remains lower and its thermal activation energy higher than in gas-phase doped samples. We surmise that the Si-Si network absorbs some of the donor electron-induced defect density by forming strained Si-Si bonds. These strained bonds widen the band tails, and thus reduce the effective electron mobility and pin the Fermi level.

Determination of the Density of Gap States in a-Si:H from Studies of Semiconductor/Oxide Multilayer Films

1987 ◽  
Vol 95 ◽  
Author(s):  
R. B. Jones ◽  
G. Moddel
Keyword(s):  
Activation Energy ◽  
Energy Gap ◽  
Multilayer Films ◽  
Thermally Grown Oxide ◽  
Experimental Results ◽  
Band Bending ◽  
The Difference ◽  
Gap States ◽  
Hydrogenated Amorphous

AbstractA method for determining the density of states [N(E)] in the upper half of the energy gap in hydrogenated amorphous silicon (a-Si:H) is proposed and experimental results are simulated. The method involves the growth and measurement of the planar conductivity in multilayer films in which each layer is separated by a thermally grown oxide. Band-bending occurs at each interface throughout the film thickness. The conductivity parallel to the layers in the films is a function of the band-bending, which in turn depends on N(E), in the energy range through which the Fermi level is shifted. Computer simulations of the oxide-induced band-bending have been used to generate curves of the conductivity as a function of layer-thickness for various N(E). By matching experimental results with the simulation curves, the N(E) may be deduced. The simulations have also been used to show the difference between the bulk conductivity activation energy and effective activation energy which is measured in films influenced by a surface oxide.

Optical constants of rf sputtered hydrogenated amorphous Si

1979 ◽  
Vol 20 (2) ◽  
pp. 716-728 ◽  
Author(s):  
Eva C. Freeman ◽  
William Paul
Keyword(s):  
Optical Constants ◽  
Amorphous Si ◽  
Hydrogenated Amorphous

a-Si:H/a-SiC:H Heterostructure for Bias-Controlled Photodetectors

1994 ◽  
Vol 336 ◽  
Author(s):  
G. De Cesare ◽  
F. Irrera ◽  
F. Lemmi ◽  
F. Palma ◽  
M. Tucci
Keyword(s):  
Applied Voltage ◽  
Energy Gap ◽  
The Other ◽  
Time Response ◽  
Wavelength Selection ◽  
Load Impedance ◽  
Amorphous Si ◽  
Hydrogenated Amorphous ◽  
High Rejection

ABSTRACTWe present a novel family of photodetectors based on hydrogenated amorphous Si/SiC p-i-n-i-p heterostructures. Front p-i-n and rear n-i-p diodes work one as a detector and the other as a load impedance, depending on the polarity of the applied voltage. Due to different absorption at different wavelengths, the devices operate as bias-controlled light detectors in either the blue or the red regions. The energy gap and the thickness of the two intrinsic layers have been optimized to obtain a sharp wavelength selection (centered at 430 and 630 nm) with high rejection-ratios and good quantum efficiencies. The I-V characteristics and the device time response are investigated and simulated by SPICE.

Raman spectra of CN vibrations of acetonitrile in aqueous and other solutions. Experimental results andab initio calculations

2005 ◽  
Vol 36 (10) ◽  
pp. 932-937 ◽  
Author(s):  
F. H. Tukhvatullin ◽  
A. Jumabaev ◽  
G. Muradov ◽  
H. A. Hushvaktov ◽  
A. A. Absanov
Keyword(s):  
Raman Spectra ◽  
Experimental Results

An Analysis of Conventional and Self-Aligned four Terminal Resistor Structures for The Determination of The Contact Resistivity from End Resistance Measurements

1986 ◽  
Vol 71 ◽  
Author(s):  
I. Suni ◽  
M. Finetti ◽  
K. Grahn
Keyword(s):  
Finite Element Method ◽  
Finite Element ◽  
Computer Model ◽  
Contact Resistivity ◽  
Experimental Results ◽  
The Finite Element Method ◽  
Model Based ◽  
A Value ◽  
And Diffusion

AbstractA computer model based on the finite element method has been applied to evaluate the effect of the parasitic area between contact and diffusion edges on end resistance measurements in four terminal Kelvin resistor structures. The model is then applied to Al/Ti/n+ Si contacts and a value of contact resistivity of Qc = 1.8×10−7.Ωcm2 is derived. For comparison, the use of a self-aligned structure to avoid parasitic effects is presented and the first experimental results obtained on Al/Ti/n+Si and Al/CoSi2/n+Si contacts are shown and discussed.

ESR and Raman Studies on Hydrogenated Amorphous Si-Sn

1984 ◽  
Vol 23 (Part 2, No. 10) ◽  
pp. L812-L814 ◽  
Author(s):  
Akiharu Morimoto ◽  
Toyotaka Kataoka ◽  
Tatsuo Shimizu
Keyword(s):  
Amorphous Si ◽  
Hydrogenated Amorphous

RAMAN SPECTRA OF THE H2SO4–SO3 AND D2SO4–SO3 SYSTEMS: EVIDENCE FOR THE OCCURRENCE OF POLYSULPHURIC ACIDS

1962 ◽  
Vol 40 (4) ◽  
pp. 658-674 ◽  
Author(s):  
R. J. Gillespie ◽  
E. A. Robinson
Keyword(s):  
Sulphuric Acid ◽  
Raman Spectra ◽  
Ionic Species ◽  
The Self ◽  
Experimental Results ◽  
Similar Work ◽  
Stretching Vibrations ◽  
Sulphur Trioxide ◽  
High Concentrations

The Raman spectra of oleums, i.e. mixtures of sulphur trioxide and sulphuric acid, have been re-examined. Similar measurements on the sulphur trioxide – deuterosulphuric acid (D2SO4) system are also reported. The experimental results and conclusions of previous similar work on oleums are discussed. By comparison of the spectra of oleums with those of the polysulphuryl halides it is shown that the polysulphuric acids H2S2O7 and H2S3O10 are present in this system. The increase in the frequency of the SO2 stretching vibrations with increasing concentration of sulphur trioxide gives evidence for the existence of higher polysulphuric acids such as H2S4O13 at high concentrations of sulphur trioxide. In relatively concentrated oleum, sulphur trioxide monomer and trimer are also present. It is shown that the self-dissociation of liquid H2S2O7 gives mainly molecular H2S2O10 and H2SO4 and not ionic species. The conclusions reached from the interpretation of the Raman spectra of the D2SO4–SO3 system are similar to those arrived at for sulphuric acid oleums. The spectra of solutions of NaHSO4 in oleums were also examined, and are discussed.

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