共查询到20条相似文献,搜索用时 31 毫秒
1.
A. V. Voitsekhovskii V. V. Vasil’ev D. V. Grigor’ev I. V. Romanov 《Russian Physics Journal》2009,52(5):441-447
The process of reconstuction of the distribution profile of hole concentration in the p
+–n structure by the method of differential Hall measurements upon implantation of ions As+ (Е = 190 keV, D = 3.1014 cm-2, j = 0.025 μA/cm2) into epitaxial films Cd
x
Hg1–x
Te for x ~ 0.2, with the initial electron concentration and mobility n = 1014 cm-3 and μ = 2∙105 cm2∙V–1∙s–1 is numerically simulated. The dependences of degree of reconstruction of the hole-concentration distribution profile on the
depth of a shunting n-layer and magnitude of the magnetic field, at which the electrophysical parameters of the p
+–n structure are measured, are calculated. The dependence of the limiting magnetic field determining the magnetic-field range
for measurements on the n-layer depth is found. It is shown that in calculations one should use the conduction values measured
at the same magnetic fields as the Hall coefficients for determination of the holeconcentration distribution profile using
the Petritz model. 相似文献
2.
Structural and optical properties of porous silicon prepared from a p
+-epitaxial layer on n-Si(111)
A. S. Len’shin V. M. Kashkarov D. A. Minakov B. L. Agapov E. P. Domashevskaya V. V. Ratnikov L. M. Sorokin 《Technical Physics》2013,58(3):404-407
The structural and optical properties of porous silicon prepared by anodic etching of an n-Si(111) wafer with a p +-homoepitaxial layer on one side are studied by scanning electron microscopy and multiple-crystal X-ray diffraction. A considerable difference between the microstructures on the sides of the wafer is found. Upon aging for 4.5 months, diffraction peaks of the por-Si structures shift from that of the substrate by δθ = ?42″ for the n-Si porous layer and ?450″ for the p +-Si porous layer. The photoluminescence band associated with the p +-layer is twice as narrow as the band associated with the n-layer and is shifted toward shorter wavelengths (higher energies) by 0.4 eV, with the intensities of the bands being the same. 相似文献
3.
The dependence of active and reactive components of the admittance of MIS structures based on heteroepitaxial Hg0.78Cd0.22Te produced by molecular-beam epitaxy as a function of bias voltage is experimentally studied in the frequency range 1 kHz
− 1 MHz. The resistance of the epitaxial-film volume is shown to significantly affect the measured admittance in the case
where the electron concentration in HgCdTe is up to 5·1014 cm− 3, and this is manifested in a number of features of the capacity-voltage characteristics. The resistance of the epitaxial-film
volume is found for the samples with different initial conductivity and for the samples with graded-band subsurface layers.
The techniques are proposed that make it possible to avoid the influence of volume resistance on the admittance of MIS structures
on the basis of heteroepitaxial HgCdTe.
__________
Translated from Izvestiya Vysshikh Uchebnykh Zavedenii, Fizika, No. 6, pp. 31–37, June, 2005. 相似文献
4.
A. D. Pogrebnyak S. N. Bratushka L. V. Malikov N. Levintant N. K. Erdybaeva S. V. Plotnikov B. P. Gritsenko 《Technical Physics》2009,54(5):667-673
The surface layer of an equiatomic TiNi alloy, which exhibits the shape memory effect in the martensitic state, is modified
with high-dose implantation of 65-keV N+ ions (the implantation dose is varied from 1017 to 1018 ions/cm2). TiNi samples are implanted by N+, Ni+-N+, and Mo+-W+ ions at a dose of 1017–1018 cm−2 and studied by Rutherford backscattering, scanning electron microscopy, energy dispersive spectroscopy, X-ray diffraction
(glancing geometry), and by measuring the nanohardness and the elastic modulus. A Ni+ concentration peak is detected between two maxima in the depth profile of the N+ ion concentration. X-ray diffraction (glancing geometry) of TiNi samples implanted by Ni+ and N+ ions shows the formation of the TiNi (B2), TiN, and Ni3N phases. In the initial state, the elastic modulus of the samples is E = 56 GPa at a hardness of H = 2.13 ± 0.30 GPa (at a depth of 150 nm). After double implantation by Ni+-N+ and W+-Mo+ ions, the hardness of the TiNi samples is ∼2.78 ± 0.95 GPa at a depth of 150 nm and 4.95 ± 2.25 GPa at a depth of 50 nm;
the elastic modulus is 59 GPa. Annealing of the samples at 550°C leads to an increase in the hardness to 4.44 ± 1.45 GPa and
a sharp increase in the elastic modulus to 236 ± 39 GPa. A correlation between the elemental composition, microstructure,
shape memory effect, and mechanical properties of the near-surface layer in TiNi is found. 相似文献
5.
M. N. Drozdov Yu. N. Drozdov M. M. Barysheva V. N. Polkovnikov N. I. Chkhalo 《Journal of Surface Investigation: X-ray, Synchrotron and Neutron Techniques》2010,4(5):807-810
The elemental composition of La/B4C multilayer metal structures is studied using SIMS on a TOF.SIMS-5 experimental setup. Analysis conditions that make it possible
to considerably enhance the depth resolution are found. They include using low-energy O2+ and Cs+ ions for sputtering and cluster secondary ions for registering matrix elements. The roughness evolution in the etching crater
region is studied in a layer-by-layer analysis. It is shown that, at an incidence angle of 45° for sputtering ions, the rms
roughness increases slightly (from an initial value of 0.5–0.7 nm) in the etching crater of the (La/B4C)70/Si structure at a depth of 0.5 μm. The profiles of elements in multilayer structures grown using two different types of magnetron
systems with stationary and high-frequency discharges are compared. The main contaminations in the structures are determined. 相似文献
6.
It is shown that dipole structures placed in a thin (less than 1 nm) near-surface layer of a high-resistivity field emitter
produce small domains on the emitting surface in which the electric field may exceed 108 V/cm. In these domains, the emitter surface potential is positive, providing effective electron transport from inside the
emitter to the emission boundary. Optimal dipole orientations ensuring maximal electric fields at the surface are found. When
the surface density of dipoles localized in the near-surface layer is on the order of 106 cm−2, one can expect an emitter-averaged emission current density of higher than 1 A/cm2. The dipole structures in the near-surface layer may persist owing to incorporated impurity molecules having a dipole moment
or result from a random combination of positively charged ionized impurities and electrons captured by deep traps. Trap charging/discharging
asymmetry accounts for the hysteresis of the emission I–V characteristics. 相似文献
7.
Asmiet Ramizy Khalid Omar Z. Hassan Omar Alattas 《Journal of nanoparticle research》2011,13(12):7139-7148
Nanostructured GaN layers are fabricated by laser-induced etching processes based on heterostructure of n-type GaN/AlN/Si grown on n-type Si(111) substrate. The effect of varying laser power density on the morphology of GaN nanostructure layer is observed.
The formation of pores over the structure varies in size and shape. The etched samples exhibit dramatic increase in photoluminescence
intensity compared to the as-grown samples. The Raman spectra also display strong band at 522 cm−1 for the Si(111) substrate and a small band at 301 cm−1 because of the acoustic phonons of Si. Two Raman active optical phonons are assigned h-GaN at 139 and 568 cm−1 due to E2 (low) and E2 (high), respectively. Surface morphology and structural properties of nanostructures are characterized
using scanning electron microscopy and X-ray diffraction. Photoluminance measurement is also taken at room temperature by
using He–Cd laser (λ = 325 nm). Raman scattering is investigated using Ar+ Laser (λ = 514 nm). 相似文献
8.
L. P. Avakyants V. S. Gorelik É. M. Temper S. M. Shcherbina 《Physics of the Solid State》1999,41(8):1369-1372
Structure in the Raman scattering spectra of near-surface n-GaAs layers (n=2×1018 cm−3) implanted with 100 keV B+ ions in the dose range 3.1×1011–1.2×1014 cm−2 is investigated. The qualitative and quantitative data on the carrier density and mobility and on the degree of amorphization
of the crystal lattice and the parameters of the nanocrystalline phase as a result of ion implantation are obtained using
a method proposed for analyzing room-temperature Raman spectra.
Fiz. Tverd. Tela (St. Petersburg) 41, 1495–1498 (August 1999) 相似文献
9.
Seulah Lee Ja Hoon Koo Jungmok Seo Sung-Dae Kim Kwang Hyun Lee Seongil Im Young-Woon Kim Taeyoon Lee 《Journal of nanoparticle research》2012,14(5):840
Although the aqueous electroless etching (AEE) method has received significant attention for the fabrication of silicon nanowires
(SiNWs) due to its simplicity and effectiveness, SiNWs grown via the AEE method have a drawback in that their surface roughness
is considerably high. Thus, we fabricated surface-modified p–n
+ junction SiNWs grown by AEE, wherein the surface roughness was reduced by a sequential processes of oxide growth using the
rapid thermal oxidation (RTO) cycling process and oxide removal with a hydrofluoric acid solution. High-resolution transmission
electron microscopy analysis confirmed that the surface roughness of the modified SiNWs was significantly decreased compared
with that of the as-fabricated SiNWs. After RTO treatment, the wettability of the SiNWs had dramatically changed from superhydrophilic
to superhydrophobic, which can be attributed to the formation of siloxane groups on the native oxide/SiNW surfaces and the
effect of the nanoscale structure. Due to the enhancement in surface carrier mobility, the current density of the surface-modified
p–n
+ junction SiNWs was approximately 6.3-fold greater than that of the as-fabricated sample at a forward bias of 4 V. Meanwhile,
the photocurrent density of the surface-modified p–n
+ junction SiNWs was considerably decreased as a result of the decreases in the light absorption area, light absorption volume,
and light scattering. 相似文献
10.
O. V. Anisimov V. P. Germogenov L. S. Khludkova O. V. Yurkovskii 《Russian Physics Journal》1999,42(1):38-46
The effect of an invertedp-region along the free surface ofn-Al
x
Ga1−x
Sb on the reverse current ofp−n structures from the given solid solution is analyzed. Expressions which describe “collection” of the inverted layer current
on the cylindrical surface of ann-region are discussed. The contribution of the near-surface and bulk components to the reverse current ofp−n structures with a semi-infiniten-region is estimated. For structures with a two-layern-region of finite thickness we have calculated the dependence of the near-surface current on the voltage across thep−n structure, the thickness of then-region, and its composition and doping level. We have compared the calculated current-voltage characteristics with experiment
using a Al0.15Ga0.85Sbp−n structure as an example.
Tomsk State University, Tomsk. Translated from Izvestiya Vysshikh Uchebnykh Zavedenii, Fizika, Vol. 42, No. 1, pp. 34–40,
January, 1999. 相似文献
11.
The influence of electron irradiation on the resistance of the NOVER-1 resist to ion-beam etching is studied. Etching is carried
out by argon ions with energies between 300 and 2500 eV. It is found that, depending on the energy and angle of incidence
of the ions on the surface of the resist, electron irradiation may either speed up or slow down the NOVER-1 etching. A clear
correlation is observed between the penetration depth of the ions in the resist and the influence of the electron irradiation
on the resistance of the resist to etching. At ion energies higher than 500 eV (ion penetration depth ≳3.5 nm) the resistance
decreases, passes through a minimum at low electron irradiation doses, and returns to the etching rate of the initial resist
at high doses. For glancing etching angles (∼ 70° to the surface normal) and low ion energies (300 eV), i.e., small ion penetration
depths (≲2.5 nm), an electron-irradiated resist is etched more slowly than the initial resist at all the electron irradiation
doses studied. This effect may be used to enhance the resistance of resist structures whose height exceeds their width, which
in this case is determined mostly by the rate of etching of the inclined facets.
Zh. Tekh. Fiz. 68, 140–142 (January 1998) 相似文献
12.
13.
I. S. Edelman E. A. Petrakovskaja D. A. Petrov S. M. Zharkov R. I. Khaibullin V. I. Nuzhdin A. L. Stepanov 《Applied magnetic resonance》2011,40(3):363-375
Fused silica plates have been implanted with 40 keV Co+ or Ni+ ions to high doses in the range of (0.25–1.0) × 1017 ions/cm2, and magnetic properties of the implanted samples have been studied with ferromagnetic resonance (FMR) technique supplemented
by transmission electron microscopy, electron diffraction and energy dispersive X-ray spectroscopy. The high-dose implantation
with 3d-ions results in the formation of cobalt and nickel metal nanoparticles in the irradiated subsurface layer of the SiO2 matrix. Co and Ni nanocrystals with hexagonal close packing and face-centered cubic structures have a spherical shape and
the sizes of 4–5 nm (for cobalt) and 6–14 nm (for nickel) in diameter. Room-temperature FMR signals from ensembles of Co and
Ni nanoparticles implanted in the SiO2 matrix exhibit an out-of-plane uniaxial magnetic anisotropy that is typical for thin magnetic films. The dose and temperature
dependences of FMR spectra have been analyzed using the Kittel formalism, and the effective magnetization and g-factor values have been obtained for Co- and Ni-implanted samples. Nonsymmetric FMR line shapes have been fitted by a sum
of two symmetrical curves. The dependences of the magnetic parameters of each curve on the implantation dose and temperature
are presented. 相似文献
14.
Low-lying equilibrium geometric structures of Phosphorus-doped aluminum cluster Al
n
P (n = 2–12) clusters obtained by an all-electron linear combination of atomic orbital approach, within spin-polarized density
functional theory, are reported. The binding energy, dissociation energy, and stability of these clusters are studied within
the local spin density approximation (LSDA) and the three-parameter hybrid generalized gradient approximation (GGA) due to
Becke-Lee-Yang-Parr (B3LYP). Ionization potentials, electron affinities, hardness, and static polarizabilities are calculated
for the ground-state structures within the GGA. It is observed that symmetric structures with the P atom occupying a peripheral
position are lowest-energy geometries of Al
n
P (n = 2, 4–11), while the P impurities of Al3P and Al12P prefer to occupy internal sites in the aluminum clusters. Generalized gradient approximation extends bond lengths as compared
to the LSDA lengths. The odd-even oscillations in the dissociation energy, the second differences in energy, the HOMO–LUMO
gaps, the ionization potential, the electron affinity, and the hardness are more pronounced within both GGA and LSDA. The
stability analysis based on the energies clearly shows the clusters with an even number of valence electrons are more stable
than clusters with odd number of valence electrons. 相似文献
15.
The influence of MeV electron irradiation on the interface states of argon implanted thin oxide MOS samples has been studied
by the thermally stimulated current (TSC) method. The oxide thickness of the structures is 18 nm. Two groups of n-type MOS structures non-implanted and implanted with 20 keV Ar+ ions and a dose of 5×1012 cm−2 are examined. Both groups are simultaneously irradiated by 23 MeV electrons with doses of 1.2×1016, 2.4×1016 or 6.0×1016 el/cm2. The energy position and density of the interface states (generated by electron irradiation, ion implantation or both treatments
of the samples) are determined. It is shown that MeV electron irradiation decreases the concentration of interface states
(like an oxygen-vacancy and di-vacancy) slightly and creates additional interface states (like an impurity-vacancy) at the
Si–SiO2 interface of argon implanted MOS structures. 相似文献
16.
V. I. Bachurin S. A. Krivelevich 《Journal of Surface Investigation: X-ray, Synchrotron and Neutron Techniques》2009,3(2):313-316
The formation of Ni x Al y intermetallic compounds in two-layer (Ni/Al) structures (nickel films deposited on aluminum substrates in vacuum) under bombardment by Ar+ ions has been studied experimentally. The method based on Rutherford backscattering of He+ ions is used to demonstrate that argon ion bombardment causes the formation of intermetallic compounds in the near-surface layer. The thickness of the intermetallic layer formed in the near-surface region substantially exceeds the projective ion path. The composition and thickness of the intermetallic layer depend mainly on the implantation dose and the substrate temperature, rather than on the ion current density. In the intermetallic layer, the content of nickel increases with increasing temperature. It has been established that, in the absence of bombardment, intermetallic phases are not observed at temperatures lower than T = 400°C and that, in the presence of bombardment, the Ni3Al intermetallic layer arises at a temperature of 320°C. 相似文献
17.
N. G. Galkin D. L. Goroshko K. N. Galkin S. V. Vavanova I. A. Petrushkin A. M. Maslov R. I. Batalov R. M. Bayazitov V. A. Shustov 《Technical Physics》2010,55(7):1036-1044
The effect of pulsed ion-beam annealing on the surface morphology, structure, and composition of single-crystal Si(111) wafers
implanted by chromium ions with a dose varying from 6 × 1015 to 6 × 1016 cm−2 and on subsequent growth of silicon is investigated for the first time. It is found that pulsed ion-beam annealing causes
chromium atom redistribution in the surface layer of the silicon and precipitation of the polycrystalline chromium disilicide
(CrSi2) phase. It is shown that the ultrahigh-vacuum cleaning of the silicon wafers at 850°C upon implantation and pulsed ion-beam
annealing provides an atomically clean surface with a developed relief. The growth of silicon by molecular beam epitaxy generates
oriented 3D silicon islands, which coalesce at a layer thickness of 100 nm and an implantation dose of 1016 cm−2. At higher implantation doses, the silicon layer grows polycrystalline. As follows from Raman scattering data and optical
reflectance spectroscopy data, semiconducting CrSi2 precipitates arise inside the silicon substrate, which diffuse toward its surface during growth. 相似文献
18.
Sh. Makhkamov N. A. Tursunov M. Ashurov R. P. Saidov S. V. Martynchenko 《Technical Physics》1999,44(1):110-112
The method of deep-level transient spectroscopy is used to investigate aspects of the formation of radiation defects in silicon
p
+-n diffusion structures when bombarded by accelerated electrons. It is shown that for base thicknesses of the p
+-n structures in the range 0.2–0.6mm a substantial change in the concentration of the radiation defects formed in this way is
observed, having a maximum at 0.25 mm. Below 0.2 mm and above 0.6 mm the concentration of radiation defects exhibits a weak
dependence on base thickness. The observed effect is explained by variation of the relative concentrations of vacancies and
interstitial silicon atoms in the base during formation of p
+-n pairs.
Zh. Tekh. Fiz. 69, 121–123 (January 1999) 相似文献
19.
C. Lazzaroni P. Chabert A. Rousseau N. Sadeghi 《The European Physical Journal D - Atomic, Molecular, Optical and Plasma Physics》2010,60(3):555-563
A microplasma is generated in the microhole (400 μm diameter) of a
molybdenum-alumina-molybdenum sandwich (MHCD type) at medium pressure
(30–200 Torr) in pure argon. Imaging and emission spectroscopy have been
used to study the sheath and electron density dynamics during the stationary
normal regime and the self-pulsing regime. Firstly, the evolution of the
microdischarge structure is studied by recording the emission intensity of
the Ar (5p[3/2]1–4s[3/2]1)_{1}) line at 427.217 nm, and Ar+
(4p′
2P3/2–4s′
2D5/2)_{5/2}) line at 427.752 nm. The maximum of
the Ar+ line is located in the vicinity of the sheath-plasma edge. In
both regimes, the experimental observations are consistent with the position
of the sheath edge calculated with an ionizing sheath model. Secondly, the
electron density is recorded by monitoring the Stark broadening of the
Hb_\beta-line. In the self-pulsing regime at 150 Torr, the electron
density reaches its maximum value of 4 × 1015 cm-3, a few
tens of ns later than the discharge current maximum. The electron density
then decays with a characteristic decay time of about 2 μs, while the
discharge current vanishes twice faster. The electron density in the
steady-state regime is two orders of magnitude lower, at about 6–8 ×
1013 cm-3. 相似文献
20.
H. Bispinck O. Ganschow L. Wiedmann A. Benninghoven 《Applied Physics A: Materials Science & Processing》1979,18(2):113-117
Thick layers of tantalum oxide prepared by thermal and anodic oxidation have been studied by combined SIMS, AES, and XPS during
depth profiling by 3keV Ar+ ion sputtering. The chemical composition of these films is revealed by the OKLL and O 1s signals and by the “lattice valence” parameter determined from the TaO
n
±
intensities. Thus the anodic film consists of a contamination layer, an oxygen-rich reactive interface and a thick homogeneous
oxide layer followed by an interface to the Ta metal. The thermal oxide shows an oxygen concentration decreasing with depth
and a broad oxide-metal interface. In both cases, carbon contamination (carbide) prevents the application of the valence model
to the clean Ta substrate. The sputtering yield of the oxides was found to be 0.6 Ta2O5/ion. 相似文献