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1.
Physical analysis of normally-off ALD Al2O3/GaN MOSFET with different substrates using self-terminating thermal oxidation-assisted wet etching technique 下载免费PDF全文
Cheng-Yu Huang 《中国物理 B》2022,31(9):97401-097401
Based on the self-terminating thermal oxidation-assisted wet etching technique, two kinds of enhancement mode Al$_{2}$O$_{3}$/GaN MOSFETs (metal-oxide-semiconductor field-effect transistors) separately with sapphire substrate and Si substrate are prepared. It is found that the performance of sapphire substrate device is better than that of silicon substrate. Comparing these two devices, the maximum drain current of sapphire substrate device (401 mA/mm) is 1.76 times that of silicon substrate device (228 mA/mm), and the field-effect mobility ($\mu_{\rm FEmax}$) of sapphire substrate device (176 cm$^{2}$/V$\cdot$s) is 1.83 times that of silicon substrate device (96 cm$^{2}$/V$\cdot$s). The conductive resistance of silicon substrate device is 21.2 $\Omega {\cdot }$mm, while that of sapphire substrate device is only 15.2 $\Omega {\cdot }$mm, which is 61% that of silicon substrate device. The significant difference in performance between sapphire substrate and Si substrate is related to the differences in interface and border trap near Al$_{2}$O$_{3}$/GaN interface. Experimental studies show that (i) interface/border trap density in the sapphire substrate device is one order of magnitude lower than in the Si substrate device, (ii) Both the border traps in Al$_{2}$O$_{3}$ dielectric near Al$_{2}$O$_{3}$/GaN and the interface traps in Al$_{2}$O$_{3}$/GaN interface have a significantly effect on device channel mobility, and (iii) the properties of gallium nitride materials on different substrates are different due to wet etching. The research results in this work provide a reference for further optimizing the performances of silicon substrate devices. 相似文献
2.
Influence of Ⅴ/Ⅲ ratio on the structural and photoluminescence properties of In0.52AlAs/In0.53GaAs metamorphic high electron mobility transistor grown by molecular beam epitaxy 下载免费PDF全文
A series of metamorphic high electron mobility transistors (MMHEMTs) with different Ⅴ/Ⅲ flux ratios are grown on CaAs (001) substrates by molecular beam epitaxy (MBE). The samples are analysed by using atomic force microscopy (AFM), Hall measurement, and low temperature photoluminescence (PL). The optimum Ⅴ/Ⅲ ratio in a range from 15 to 60 for the growth of MMHEMTs is found to be around 40. At this ratio, the root mean square (RMS) roughness of the material is only 2.02 nm; a room-temperature mobility and a sheet electron density are obtained to be 10610.0cm^2/(V.s) and 3.26×10^12cm^-2 respectively. These results are equivalent to those obtained for the same structure grown on InP substrate. There are two peaks in the PL spectrum of the structure, corresponding to two sub-energy levels of the In0.53Ga0.47As quantum well. It is found that the photoluminescence intensities of the two peaks vary with the Ⅴ/Ⅲ ratio, for which the reasons are discussed. 相似文献
3.
Synthesis, characterization of the pentacene and fabrication of pentacene field-effect transistors 下载免费PDF全文
A comprehensive understanding of the organic semiconductor material pentacene is meaningful for organic fieldeffect transistors (OFETs). Thin films of pentacene are the most mobile molecular films known to date. This paper reported that the pentacene sample was successfully synthesized. The purity of pentacene is up to 95%. The results of a joint experimental investigation based on a combination of infrared absorption spectra, mass spectra (MS), element analysis, x-ray diffraction (XRD) and atom force microscopy (AFM). The authors fabricated OFET with the synthesized pentacene. Its field effect mobility is about 1.23 cm^2/(V·s) and on-off ratio is above 10^6. 相似文献
4.
Synthesis, characterization of the pentacene and fabrication of pentacene field-effect transistors 下载免费PDF全文
A comprehensive understanding of the organic semiconductor material
pentacene is meaningful for organic field-effect transistors (OFETs).
Thin films of pentacene are the most mobile molecular films known to
date. This paper reported that the pentacene sample was successfully
synthesized. The purity of pentacene is up to 95\%. The results of a
joint experimental investigation based on a combination of infrared
absorption spectra, mass spectra (MS), element analysis, x-ray
diffraction (XRD) and atom force microscopy (AFM). The authors
fabricated OFET with the synthesized pentacene. Its field effect
mobility is about 1.23\,cm$^2$/(V$\cdot$s) and on--off ratio is above
10$^{6}$. 相似文献
5.
The density functional theory (DFT)(b3p86) of Gaussian 03 has been
used to optimize the structure of the Co$_{2}$ molecule, a transition
metal element molecule. The result shows that the ground state for
the Co$_{2}$ molecule is a 7-multiple state, indicating a spin
polarization effect in the Co$_{2}$ molecule. Meanwhile, we have not
found any spin pollution because the wavefunction of the ground state
is not mingled with wavefunctions of higher-energy states. So for the
ground state of Co$_{2}$ molecule to be a 7-multiple state is the
indicative of spin polarization effect of the Co$_{2}$ molecule, that
is, there exist 6 parallel spin electrons in a Co$_{2}$ molecule. The
number of non-conjugated electrons is the greatest. These electrons
occupy different spacial orbitals so that the energy of the Co$_{2}$
molecule is minimized. It can be concluded that the effect of
parallel spin in the Co$_{2}$ molecule is larger than the effect of
the conjugated molecule, which is obviously related to the effect of
electron d delocalization. In addition, the Murrell--Sorbie potential
functions with the parameters for the ground state and the other
states of the Co$_{2}$ molecule are derived. The dissociation energy
$De$ for the ground state of Co$_{2}$ molecule is 4.0489eV,
equilibrium bond length $R_{\rm e}$ is 0.2061~nm, and vibration
frequency $\omega _\e $ is 378.13~cm$^{ - 1}$. Its diatomic molecule
force constants $f_2$, $f_3$, and $f_4$ are 2.4824~aJ$\cdot$nm$^{ -
2}$, -7.3451~aJ$\cdot$nm$^{ - 3}$, and 11.2222~aJ$\cdot$nm$^{ - 4
}$respectively(1~aJ=$10^{-18}$~J). The other spectroscopic data for
the ground state of Co$_{2}$ molecule $\omega_{\e}\chi _{\e}$,
$B_{\e}$, and $\alpha_{\e}$ are 0.7202~cm$^{-1}$, 0.1347~cm$^{-1 }$,
and 2.9120$\times $ 10$^{-1}$~cm$^{-1}$ respectively. And
$\omega_{\e}\chi _{\e}$ is the non-syntonic part of frequency,
$B_{\e}$ is the rotational constant, $\alpha_{\e}$ is revised
constant of rotational constant for non-rigid part of Co$_2$
molecule. 相似文献
6.
Optical and electrical properties of BaSnO3 and In2O3 mixed transparent conductive films deposited by filtered cathodic vacuum arc technique at room temperature 下载免费PDF全文
Jian-Ke Yao 《中国物理 B》2023,32(1):18101-018101
For the crystalline temperature of BaSnO$_{3}$ (BTO) was above 650 ℃, the transparent conductive BTO-based films were always deposited above this temperature on epitaxy substrates by pulsed laser deposition or molecular beam epitaxy till now which limited there application in low temperature device process. In the article, the microstructure, optical and electrical of BTO and In$_{2}$O$_{3}$ mixed transparent conductive BaInSnO$_x$ (BITO) film deposited by filtered cathodic vacuum arc technique (FCVA) on glass substrate at room temperature were firstly reported. The BITO film with thickness of 300 nm had mainly In$_{2}$O$_{3}$ polycrystalline phase, and minor polycrystalline BTO phase with (001), (011), (111), (002), (222) crystal faces which were first deposited at room temperature on amorphous glass. The transmittance was 70%-80% in the visible light region with linear refractive index of 1.94 and extinction coefficient of 0.004 at 550-nm wavelength. The basic optical properties included the real and imaginary parts, high frequency dielectric constants, the absorption coefficient, the Urbach energy, the indirect and direct band gaps, the oscillator and dispersion energies, the static refractive index and dielectric constant, the average oscillator wavelength, oscillator length strength, the linear and the third-order nonlinear optical susceptibilities, and the nonlinear refractive index were all calculated. The film was the n-type conductor with sheet resistance of 704.7 $\Omega /\Box $, resistivity of 0.02 $\Omega \cdot$cm, mobility of 18.9 cm$^{2}$/V$\cdot$s, and carrier electron concentration of $1.6\times 10^{19}$ cm$^{-3}$ at room temperature. The results suggested that the BITO film deposited by FCVA had potential application in transparent conductive films-based low temperature device process. 相似文献
7.
Study on spectroscopic parameters and molecular constants of HCl(X~1Σ~+) molecule by using multireference configuration interaction approach 下载免费PDF全文
Equilibrium internuclear separations, harmonic frequencies
and potential energy curves (PECs) of HCl($X^{1}\Sigma ^{ + })$
molecule are investigated by using the highly accurate valence
internally contracted multireference configuration interaction
(MRCI) approach in combination with a series of
correlation-consistent basis sets in the valence range. The PECs are
all fitted to the Murrell--Sorbie function, and they are used to
accurately derive the spectroscopic parameters ($D_{\rm e}$,
$D_{0}$, $\omega_{\rm e}\chi_{\rm e}$, $\alpha_{\rm e}$ and $B_{\rm
e})$. Compared with the available measurements, the PEC obtained at
the basis set, aug-cc-pV5Z, is selected to investigate the
vibrational manifolds. The constants $D_{0}$, $D_{\rm e}$, $R_{\rm
e}$, $\omega_{\rm e}$, $\omega_{\rm e}\chi_{\rm e}$, $\alpha_{\rm
e}$ and $B_{\rm e}$ at this basis set are 4.4006~eV, 4.5845~eV,
0.12757~nm, 2993.33~cm$^{ - 1}$, 52.6273~cm$^{ - 1}$, 0.2981~cm$^{ -
1}$ and 10.5841~cm$^{ - 1}$, respectively, which almost perfectly
conform to the available experimental results. With the potential
determined at the MRCI/aug-cc-pV5Z level of theory, by numerically
solving the radial Schr\"{o}dinger equation of nuclear motion in the
adiabatic approximation, a total of 21 vibrational levels are
predicted. Complete vibrational levels, classical turning points,
inertial rotation and centrifugal distortion constants are
reproduced, which are in excellent agreement with the available
Rydberg--Klein--Rees data. Most of these theoretical vibrational
manifolds are reported for the first time to the best of our
knowledge. 相似文献
8.
Investigations on spectroscopic parameters, vibrational levels, classical turning points and inertial rotation and centrifugal distortion constants for the X1∑+g state of sodium dimer 下载免费PDF全文
The density functional theory (B3LYP, B3P86) and the quadratic
configuration-interaction method including single and double
substitutions (QCISD(T), QCISD) presented in Gaussian03 program
package are employed to calculate the equilibrium internuclear
distance $R_{\rm e}$, the dissociation energy $D_{\rm e }$ and the
harmonic frequency $\omega _{\rm e}$ for the $X{}^{1}\Sigma^{ +
}_{\rm g}$ state of sodium dimer in a number of basis sets. The
conclusion is gained that the best $R_{\rm e}$, $D_{\rm e}$ and
$\omega _{\rm e}$ results can be attained at the
QCISD/6-311G(3df,3pd) level of theory. The potential energy curve at
this level of theory for this state is obtained over a wide
internuclear separation range from 0.16 to 2.0~nm and is fitted to
the analytic Murrell--Sorbie function. The spectroscopic parameters
$D_{\rm e}$, $D_{0}$, $R_{\rm e}$, $\omega _{\rm e}$,
$\omega _{\rm e}\chi _{\rm e}$,
$\alpha _{\rm e}$
and $B_{\rm e}$ are calculated to be 0.7219~eV,
0.7135~eV, 0.31813~nm, 151.63~cm$^{ - 1}$, 0.7288~cm$^{ - 1}$,
0.000729~cm$^{ - 1}$ and 0.1449~cm$^{ - 1}$, respectively, which are in good
agreement with the measurements. With the potential obtained at the
QCISD/6-311G(3df,3pd) level of theory, a total of 63 vibrational
states is found when $J=0$ by solving the radial Schr\"{o}dinger equation
of nuclear motion. The vibrational level, corresponding classical turning
point and inertial rotation constant are computed for each vibrational
state. The centrifugal distortion constants
($D_{\upsilon }\, H_{\upsilon }$,
$L_{\upsilon }$, $M_{\upsilon }$, $N_{\upsilon }$ and $O_{\upsilon })$ are
reported for the first time for the first 31 vibrational states when $J=0$. 相似文献
9.
Effect of interface roughness on the carrier transport in germanium MOSFETs investigated by Monte Carlo method 下载免费PDF全文
Interface roughness strongly influences the performance
of germanium metal--organic--semiconductor field effect transistors
(MOSFETs). In this paper, a 2D full-band Monte Carlo simulator is
used to study the impact of interface roughness scattering on
electron and hole transport properties in long- and short- channel
Ge MOSFETs inversion layers. The carrier effective mobility in the
channel of Ge MOSFETs and the in non-equilibrium transport
properties are investigated. Results show that both electron and
hole mobility are strongly influenced by interface roughness
scattering. The output curves for 50~nm channel-length double gate n
and p Ge MOSFET show that the drive currents of n- and p-Ge MOSFETs
have significant improvement compared with that of Si n- and
p-MOSFETs with smooth interface between channel and gate dielectric.
The $82\%$ and $96\%$ drive current enhancement are obtained for the
n- and p-MOSFETs with the completely smooth interface. However, the
enhancement decreases sharply with the increase of interface
roughness. With the very rough interface, the drive currents of Ge
MOSFETs are even less than that of Si MOSFETs. Moreover, the
significant velocity overshoot also has been found in Ge MOSFETs. 相似文献
10.
Elastic collisions between Si and D atoms at low temperatures and accurate analytic potential energy function and molecular constants of the SiD(χ^2П) radical 下载免费PDF全文
Interaction potential of the SiD(X2Π) radical is constructed by using the CCSD(T) theory in combination with the largest correlation-consistent quintuple basis set augmented with the diffuse functions in the valence range. Using the interaction potential, the spectroscopic parameters are accurately determined. The present D0, De, Re, ωe, αe and Be values are of 3.0956 eV, 3.1863 eV, 0.15223 nm, 1472.894 cm-1, 0.07799 cm-1 and 3.8717 cm-1, respectively, which are in excellent agreement with the measurements. A total of 26 vibrational states is predicted when J=0 by solving the radial Schro¨dinger equation of nuclear motion. The complete vibrational levels, classical turning points, initial rotation and centrifugal distortion constants when J=0 are reported for the first time, which are in good accord with the available experiments. The total and various partial-wave cross sections are calculated for the elastic collisions between Si and D atoms in their ground states at 1.0×10-11–1.0×10-3 a.u. when the two atoms approach each other along the SiD(X2Π) potential energy curve. Four shape resonances are found in the total elastic cross sections, and their resonant energies are of 1.73×10-5, 4.0×10-5, 6.45×10-5 and 5.5×10-4 a.u., respectively. Each shape resonance in the total elastic cross sections is carefully investigated. The results show that the shape of the total elastic cross sections is mainly dominated by the s partial wave at very low temperatures. Because of the weakness of the shape resonances coming from the higher partial waves, most of them are passed into oblivion by the strong s partial-wave elastic cross sections. 相似文献
11.
Enhanced interface properties of diamond MOSFETs with Al_2O_3 gate dielectric deposited via ALD at a high temperature 下载免费PDF全文
《中国物理 B》2021,30(5):58101-058101
The interface state of hydrogen-terminated(C–H) diamond metal–oxide–semiconductor field-effect transistor(MOSFET) is critical for device performance. In this paper, we investigate the fixed charges and interface trap states in C–H diamond MOSFETs by using different gate dielectric processes. The devices use Al_2O_3 as gate dielectrics that are deposited via atomic layer deposition(ALD) at 80℃ and 300℃, respectively, and their C–V and I–V characteristics are comparatively investigated. Mott–Schottky plots(1/C~2–VG) suggest that positive and negative fixed charges with low density of about 1011 cm~(-2) are located in the 80-℃-and 300-℃ deposition Al_2O_3 films, respectively. The analyses of direct current(DC)/pulsed I–V and frequency-dependent conductance show that the shallow interface traps(0.46 e V–0.52 e V and0.53 e V–0.56 e V above the valence band of diamond for the 80-℃ and 300-℃ deposition conditions, respectively) with distinct density(7.8 × 10~(13) e V~(-1)·cm~(-2)–8.5 × 10~(13) e V-1·cm~(-2) and 2.2 × 1013 e V~(-1)·cm~(-2)–5.1 × 10~(13) e V~(-1)·cm~(-2) for the80-℃-and 300-℃-deposition conditions, respectively) are present at the Al_2O_3/C–H diamond interface. Dynamic pulsed I–V and capacitance dispersion results indicate that the ALD Al_2O_3 technique with 300-℃ deposition temperature has higher stability for C–H diamond MOSFETs. 相似文献
12.
Effects of concentration and annealing on the performance of regioregular poly(3-hexylthiophene) field-effect transistors 下载免费PDF全文
This paper investigates the effects of concentration on the
crystalline structure, the morphology, and the charge carrier
mobility of regioregular poly(3-hexylthiophene) (RR-P3HT)
field-effect transistors (FETs). The RR-P3HT FETs with RR-P3HT as an
active layer with different concentrations of RR-P3HT solution from
0.5~wt% to 2~wt% are prepared. The results indicate that the
performance of RR-P3HT FETs improves drastically with the increase
of RR-P3HT weight percentages in chloroform solution due to the
formation of more microcrystalline lamellae and bigger nanoscale
islands. It finds that the field-effect mobility of RR-P3HT FET with
2~wt% can reach 5.78× 10^-3~cm2/Vs which is higher
by a factor of 13 than that with 0.5~wt%. Further, an appropriate
thermal annealing is adopted to improve the performance of RR-P3HT
FETs. The field-effect mobility of RR-P3HT FETs increases
drastically to 0.09~cm2/Vs by thermal annealing at
150~℃, and the value of on/off current ratio can reach
10^4. 相似文献
13.
Absorption spectra of β -carotene in 31 solvents
are measured in ambient conditions. Solvent effects on the 0--0 band
energy, the bandwidth, and the transition moment of the S0 →
S2 transition are analysed. The discrepancies between published
results of the solvent effects on the 0--0 band energy are
explained by taking into account microscopic solute-solvent
interactions. The contributions of polarity and polarizability of
solvents to 0--0 band energy and bandwidth are quantitatively
distinguished. The 0--0 transition energy of the S2 state at the gas
phase is predicted to locate between 23000 and 23600~cm-1. 相似文献
14.
The hole subband structures and effective masses of tensile strained Si/Sil-yGey quantum wells are calculated by using the 6 × 6 k·p method. The results show that when the tensile strain is induced in the quantum well, the light-hole state becomes the ground state, and the light hole effective masses in the growth direction are strongly reduced while the in-plane effective masses are considerable. Quantitative calculation of the valence intersubband transition between two light hole states in a 7nm tensile strained Si/Si0.55Ge0.45 quantum well grown on a relaxed Si0.5Ge0.5 (100) substrates shows a large absorption coefficient of 8400 cm^-1. 相似文献
15.
Formation mechanism of Ge nanocrystals embedded in SiO2 studied by fluorescence x-ray absorption fine structure 下载免费PDF全文
This paper reports that the Ge nanocrystals embedded in SiO2 matrix are grown on Si(100) and quartz-glass substrates, and the formation mechanism is systematically studied by using fluorescence x-ray absorption fine structure (XAFS). It is found that the formation of Ge nanocrystals strongly depends on the properties of substrate materials. In the as-prepared samples with Ge molar content of 60%, Ge atoms exist in amorphous Ge (about 36%) and GeO2 (about 24%) phases. At the annealing temperature of 1073 K, on the quartz-glass substrate Ge nanocrystals are generated from crystallization of amorphous Ge, rather than from the direct decomposition of GeO2 in the as-deposited sample. However, on the Si(100) substrate, the Ge nanocrystals are generated partly from crystallization of amorphous Ge, and partly from GeO2 phases through the permutation reaction with Si substrate. Quantitative analysis reveals that about 10% of GeO2 in the as-prepared sample are permuted with Si wafer to form Ge nanocrystals. 相似文献
16.
A novel vertical stack heterostructure CMOSFET is investigated, which is
structured by strained SiGe/Si with a hole quantum well channel in the
compressively strained Si量子信道 异质结构 CMOSFET 量子论 量子阱 strained SiGe/Si, quantum well channel, heterostructure CMOSFET, poly-SiGe gate Project supported by the Preresearch from National Ministries and Commissions (Grant Nos 51408061104DZ01, 51439010904DZ0101). 2/2/2006 12:00:00 AM 2006-01-022006-03-16 A novel vertical stack heterostructure CMOSFET is investigated, which is structured by strained SiGe/Si with a hole quantum well channel in the compressively strained Sil-xGex layer for p-MOSFET and an electron quantum well channel in the tensile strained Si layer for n-MOSFET. The device possesses several advantages including: 1) the integration of electron quantum well channel with hole quantum well channel into the same vertical layer structure; 2) the gate work function modifiability due to the introduction of poly-SiGe as a gate material; 3) better transistor matching; and 4) flexibility of layout design of CMOSFET by adopting exactly the same material lays for both n-channel and p-channel. The MEDICI simulation result shows that p-MOSFET and n-MOSFET have approximately the same matching threshold voltages. Nice performances are displayed in transfer characteristic, transconductance and cut-off frequency. In addition, its operation as an inverter confirms the CMOSFET structured device to be normal and effective in function. 相似文献
17.
本文考虑带有黑洞视界和宇宙视界的Kiselev时空.研究以黑洞视界和宇宙视界为边界的系统的热力学性质.统一地给出了两个系统的热力学第一定律;在黑洞视界半径远小于宇宙视界半径的情况下,近似地计算了通过宇宙视界和黑洞视界的热能.然后,探讨Kiselev时空的物质吸积特性.在吸积能量密度正比于背景能量密度的条件下给出黑洞的吸积率,讨论了黑洞吸积率与暗能量态方程参数的关系. 相似文献
18.
Zi-Hao Chen 《中国物理 B》2023,32(1):17301-017301
The Ga$_{2}$O$_{3}$ films are deposited on the Si and quartz substrates by magnetron sputtering, and annealing. The effects of preparation parameters (such as argon-oxygen flow ratio, sputtering power, sputtering time and annealing temperature) on the growth and properties ($e.g.$, surface morphology, crystal structure, optical and electrical properties of the films) are studied by x-ray diffractometer (XRD), scanning electron microscope (SEM), and ultraviolet-visible spectrophotometer (UV-Vis). The results show that the thickness, crystallization quality and surface roughness of the $\beta $-Ga$_{2}$O$_{3}$ film are influenced by those parameters. All $\beta $-Ga$_{2}$O$_{3 }$films show good optical properties. Moreover, the value of bandgap increases with the enlarge of the percentage of oxygen increasing, and decreases with the increase of sputtering power and annealing temperature, indicating that the bandgap is related to the quality of the film and affected by the number of oxygen vacancy defects. The $I$-$V$ curves show that the Ohmic behavior between metal and $\beta $-Ga$_{2}$O$_{3}$ films is obtained at 900 ${^\circ}$C. Those results will be helpful for the further research of $\beta $-Ga$_{2}$O$_{3}$ photoelectric semiconductor. 相似文献
19.
This paper reports that a novel type of suspended ZnO nanowire field-effect
transistors (FETs) were successfully fabricated using a
photolithography process, and their electrical properties were
characterized by I--V measurements. Single-crystalline ZnO
nanowires were synthesized by a hydrothermal method, they were used
as a suspended ZnO nanowire channel of back-gate field-effect
transistors (FET). The fabricated suspended nanowire FETs showed a
p-channel depletion mode, exhibited high on--off current ratio of
~105. When VDS=2.5 V, the peak transconductances
of the suspended FETs were 0.396 μS, the oxide capacitance was
found to be 1.547 fF, the pinch-off voltage VTH was about
0.6 V, the electron mobility was on average 50.17 cm2/Vs. The
resistivity of the ZnO nanowire channel was estimated to be
0.96× 102Ω cm at VGS = 0 V. These
characteristics revealed that the suspended nanowire FET fabricated
by the photolithography process had excellent performance. Better
contacts between the ZnO nanowire and metal electrodes could be
improved through annealing and metal deposition using a focused ion
beam. 相似文献
20.
This paper studies the process of mutual neutralization of Si^+ and H^- ions in slow collisions within the multichannel Landau-Zener model. All important ionic-covalent couplings in this collision system are included in the collision dynamics. The cross sections for population of specific final states of product Si atom are calculated in the CM energy range 0.05 e∨/u-5 ke∨/u. Both singlet and triplet states are considered. At collision energies below -10 e∨/u, the most populated singlet state is Si(3p4p, ^1S0), while for energies above -150e∨/u it is the Si(3p, 4p, ^1P1) state. In the case of triplet states, the mixed 3p4p(^3S1 +^3P0) states are the most populated in the entire collision energy range investigated. The total cross section exhibits a broad maximum around 200 300e∨/u and for ECM ≤ 10e∨/u it monotonically increases with decreasing the collision energy, reaching a value of 8 × 10^-13 cm^2 at ECM = 0.05 e∨/u. The ion-pair formation process in Si(3p^2 ^3PJ)+H(1s) collisions has also been considered and its cross section in the considered energy range is very small (smaller than 10^-20 cm^2 in the energy region below 1 ke∨/u). 相似文献