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1.
D. F. Aminev V. S. Bagaev T. I. Galkina A. Yu. Klokov V. S. Krivobok V. G. Ralchenko A. V. Savel’ev 《Semiconductors》2009,43(9):1159-1163
Low-temperature (5K) photoluminescence of silicon substrates in the range 0.8–1.2 eV is studied before and after deposition
of polycrystalline diamond films. The diamond films were deposited in the microwave plasma onto high-purity dislocation-free
silicon (with the resitivity ρ ≈ 3 kΩ cm) subjected to mechanical polishing or more delicate chemical and mechanical polishing.
The deposition temperature was 750–850°C. In the photoluminescence spectra of the samples with the substrates polished chemically
and mechanically, two lines, D
1 and D
2, corresponding to the dislocation-related emission are recorded. Generation of dislocations in the substrates is caused by
efficient adhesion of the diamond film and, as a result, by internal stresses that relax with the formation of dislocations.
The experimental spectra are practically identical to the photoluminescence spectra observed in silicon (ρ ≈ 100 Ω cm) with
the density of dislocations ∼104 cm−2. 相似文献
2.
V. A. Volodin E. I. Gatskevich A. V. Dvurechenskii M. D. Efremov G. D. Ivlev A. I. Nikiforov D. A. Orekhov A. I. Yakimov 《Semiconductors》2003,37(11):1315-1320
The effect of pulsed ruby laser radiation on Ge nanoclusters grown on a (100)-oriented Si substrate is studied. The energy density of radiation corresponds to the melting threshold of the Si surface. Changes in the structure of nanoclusters are analyzed by comparing the experimental Raman spectra to those calculated in terms of Born-von Karman and Vol’kenstein models. It is established that the action of one pulse changes the cluster size and partly relieves the compression. Still greater changes take place in a sample subjected to ten pulses. The Ge nanoclusters transform into clusters of GexSi1?x solid solution, presumably due to the stress-and vacancy-aided diffusion. Laser-induced thermal processes in germanium nanoclusters in silicon are numerically simulated. 相似文献
3.
The epitaxial growth and characterization of in-situ germanium and boron (Ge/B) doped Si epitaxial films is described. As
indicated by secondary ion mass spectroscopy and spreading resistance measurements, the total and electrically activated B
concentrations are essentially identical and independent of Ge incorporation. The B and Ge concentrations are uniformly distributed
in these Ge/B doped films. A slight enhancement of Hall mobility is obtained, possibly due to the stress relief induced by
Ge counterdoping. Carrier conduction in these films is due to the activated B with an activation energy of 0.04 eV as revealed
by conductivity versus temperature measurements. Ge atoms appear to be isoelectronic with Si atoms in these films. A slight
degradation of minority carrier diffusion length is observed. Electrical characterization of PN diodes on these Ge/B doped
films do not reveal any anomaly. SiO2 on these Ge/B doped films has similar oxide fixed charge density, interface state density and dielectric breakdown strength
compared to silicon dioxide on boron doped epitaxial films. Electron injection reveals a different transport mechanism of
the SiO2 grown on these Ge/B doped films. 相似文献
4.
5.
Yiqun Shen Ning Xu Wei Hu Xiaofeng Xu Jian Sun Zhifeng Ying Jiada Wu 《Solid-state electronics》2008,52(11):1833-1836
The preparation of bismuth doped ZnSe films on silicon (1 0 0) by pulsed laser deposition (PLD) is reported. Bismuth was used as a p-type dopant source material for ZnSe. The stable p-type films with hole carrier concentration of about 1016–1018 cm?3 were obtained. By scanning electron microscopy (SEM) and X-ray diffraction (XRD), it was found that the ambient pressure during film deposition has much to do with the morphology and crystallinity of the as-deposited products. The presence of Bi in the Bi-doped ZnSe films was confirmed by the X-ray photoelectron spectroscopy (XPS) and the possibility of a BiZn–2VZn complex forming a shallow acceptor level was discussed. 相似文献
6.
K. P. Abdurakhmanov Sh. B. Utamuradova Kh. S. Daliev S. G. Tadjy-Aglaeva R. M. Érgashev 《Semiconductors》1998,32(6):606-607
Deep-level transient spectroscopy has been used to study the effect of Ge atoms on the behavior of Mn in Si. It is shown that
Ge atoms introduced into Si during growth manifest no electrical activity, even though their concentration is rather high:
1016–1019 cm−3. It is established that the presence of Ge atoms in the Si lattice enhances the efficiency of the formation of the deep levels
E
c
-0.42 eV and E
c
-0.54 eV, which are associated with Mn in the Si lattice: the concentration of these deep levels in Si〈Ge, Mn〉 samples is
a factor of 3–4 greater than in Si〈Mn〉. It is found that the presence of Ge atoms stabilizes the properties of the Mn levels
in Si: They anneal more slowly than in Si〈Mn〉 by a factor of 5–6. It is assumed that the detected effects are associated with
the features of the defect structure of Si doped with Ge and Mn.
Fiz. Tekh. Poluprovodn. 32, 676–678 (June 1998) 相似文献
7.
8.
《Electron Devices, IEEE Transactions on》1979,26(11):1738-1742
The newly discovered phenomenon of resistance decrease in heavily doped polycrystalline silicon resistors by conduction of high current densiy has been investigated experimentally. Threshold values exist for the impurity concentration and for the applied current density for the occurrence of this phenomenon. Decreased resistance is stable as far as current higher than the threshold value is not applied thereafter. Applications to D/A converters and operational amplifiers are described. Electrical trimming of resistors in the circuits with accuracy of ±0.01 percent is easily attained. 相似文献
9.
A hyperbolic-sine relationship describing the current-voltage characteristics of lightly-doped, n-type polycrystalline silicon films is derived. The derivation is based on a previous model which assumes that electron-trapping states exist at the grain boundaries of the polycrystalline film. The trapped electrons cause a surface-depletion zone and a potential barrier at each grain boundary. Electrons are transported over the barriers by thermionic emission. Conduction measurements carried out on commercially prepared samples are in good agreement with the theory developed both in voltage and temperature dependence. The model parameters obtained from conduction measurements correspond reasonably well with values inferred from scanning electron micrographs. 相似文献
10.
Silicon thin films prepared by chemical vapor deposition of silane at very low pressures (4 mTorr) in an experimental reactor
that allows deposition with and without plasma enhancement have been characterized. The temperature range of the substrates
on which the films were deposited was varied from 500 to 800° C for plasma-enhanced depositions and 600 to 800° C for nonplasma
depositions. Conductivity measurements as a function of temperature as well as average grain size and crystallographic texture
measurements were performed. The results indicate that the films deposited with the assistance of a plasma were amorphous
at deposition temperatures of 650° C and below and polycrystalline at deposition temperatures of 700° C and above. In the
temperature regime investigated, this amorphous-to-crystalline transition was not observed in films deposited without the
assistance of a plasma. Furthermore, all the films deposited at temperatures of 650° C and below have been found to have significantly
different properties from the similarly prepared films deposited at higher temperatures. 相似文献
11.
This paper discusses how the structure and electrical conductivity of polycrystalline silicon films grown by molecular-beam
deposition are affected by the growth conditions. It shows that the films can be improved by applying to the substrate a voltage
in the range 50–300 V, negative with respect to the silicon source. Such films also have higher conductivity. The results
are explained in terms of bombardment of the growing film by dopant ions.
Fiz. Tekh. Poluprovodn. 34, 291–295 (March 1997) 相似文献
12.
Edgardo Gabilli Sergio Guerri Guido Masetti Maurizio Severi 《Solid-state electronics》1977,20(11):925-930
The resistivity of phosphorus-doped sputter-deposited polycrystalline silicon films has been extensively investigated as a function of many technological parameters with the aim of establishing whether these films can be doped to the desired resistivity values for MOS applications. An empirical expression has been determined for a standard doping process which relates the final sheet resistance of the film to the deposition rate and to the temperature of an annealing treatment carried out before predeposition. Once specified the desired sheet resistance, the two above parameters can be chosen in such a way as to minimize the annealing temperature, if high-temperature processing is to be prevented. 相似文献
13.
《Materials Science in Semiconductor Processing》2012,15(6):722-730
Polycrystalline silicon balls are popularly used for solar cells to lower cost and improve their light collection capability. This article investigates on the microstructure evolution during solidification of polycrystalline silicon. The uniform droplet spray process, a controlled capillary jet break-up process, which enables stringent control of the nucleation and microstructure evolution during solidification of alloy droplets in a thermal spray process, was used to produced mono-sized silicon droplets. The experimental parameters for production of silicon droplets were established and the solidification behavior of silicon droplets was investigated using the modification of the free dendritic growth model and the dendritic fragmentation model. This enabled us to correctly establish the transition supercooling for transformation from lateral growth mode to continuous growth mode to be between 81 K and 172 K. The model was used to predict the microstructure of polycrystalline silicon droplets for solar cells produced by a droplet based manufacturing method, enabling greater control over process parameters and its relation to the final microstructure. 相似文献
14.
Chun-Yen Chang Hsiao-Yi Lin Tan Fu Lei Juing-Yi Cheng Liang-Po Chen Bau-Tong Dai 《Electron Device Letters, IEEE》1996,17(3):100-102
A top-gate p-channel polycrystalline thin film transistor (TFT) has been fabricated using the polycrystalline silicon (poly-Si) film as-deposited by ultrahigh vacuum chemical vapor deposition (UHV/CVD) and polished by chemical mechanical polishing (CMP). In this process, long-term recrystallization in channel films is not needed. A maximum field effect mobility of 58 cm2/V-s, ON/OFF current ratio of 1.1 107, and threshold voltage of -0.54 V were obtained. The characteristics are not poor. In this work, therefore, we have demonstrated a new method to fabricate poly-Si TFT's 相似文献
15.
There exists a need for a large-bias conduction model of polysilicon films used in VLSI/ULSI and in high power integrated circuits. A large-bias conduction model has been developed by extending the emission-based models of Lu et al. (1983) and Mandurah et al. (1981) valid for small-bias, small-signal conditions. The following large-bias effects have been taken into account: (1) asymmetry of potential distribution around grain boundaries and (2) avalanche multiplication of carriers in the grain boundary layers at high electric fields. Since the exact nature of the grain boundary material is not yet known, and there is no direct method for determining the model parameters relating to grain boundaries, these were extracted by the parametric fitting of resistance versus temperature data of polysilicon resistors near room temperature with the above small-signal resistivity models modified by including Fermi-Dirac distribution. The model has been validated with experimental data on the current-voltage characteristics of ion-beam sputtered polysilicon resistors of different sizes and aspect ratios. The dependence of model parameters relating to grain boundary scattering and avalanche multiplication on the dimensions of resistors have been explained physically. The increased kink effect in polysilicon TFT's may also be predicted from the present theory. Some results on the I-V characteristics of polyresistors trimmed by high current pulses have been discussed qualitatively in the light of the present model. Although the model involves numerical integrations and a few iterations, it is reasonably fast in execution 相似文献
16.
N. A. Sobolev A. M. Emel’yanov V. V. Zabrodskiĭ N. V. Zabrodskaya V. L. Sukhanov E. I. Shek 《Semiconductors》2007,41(5):616-618
Light-emitting diodes (LEDs) have been fabricated in which optically active centers are formed by implantation of erbium ions into silicon and subsequent high-temperature annealing in an oxidizing atmosphere and the p-n junction and the ohmic contact are formed by chemical vapor deposition of polycrystalline silicon layers doped with boron and phosphorus, respectively. The luminescent properties of the LEDs have been studied. Use of polycrystalline layers makes it possible to eliminate the losses in the bulk of the light-emitting Si:Er layer. These losses are inevitable if the conventional ion implantation and diffusion methods are employed. At 80 K, the variation of electroluminescence spectra in the spectral range of the dislocation-related luminescence with the drive current is well described if the spectrum is decomposed into three Gaussian components whose peak positions and widths are current-independent and amplitudes linearly increase with the current. At 300 K, a single peak is observed in the spectral range of the dislocation-related luminescence at ~1.6 μm. 相似文献
17.
Electrical switching characteristics using polycrystalline silicon–germanium (poly-Sil?xGex) gate for P-channel power trench MOSFETs was investigated. Switching time reduction of over 22% was observed when the boron-doped poly-Si gate was replaced with a similarly boron-doped poly-SiGe gate on the P-channel power MOSFETs. The fall time (Tf) on MOSFETs with poly-SiGe gate, was found to be ~11 ns lesser than the poly-Si gate MOSFET which is ~60% improvement in switching performance. However, all the switching improvement was observed during the fall times (Tf). The reason could be the higher series resistance in the switching test circuit masking any reduction in the rise times (Tr). Faster switching is achieved due to a lower gate resistance (Rg) offered by the poly-SiGe gate electrode as compared to poly-silicon (pSi) material. The pSi gate resistance was found to be 6.25 Ω compared to 3.75 Ω on the poly-SiGe gate measured on the same device. Lower gate resistance (Rg) also means less power is lost during switching thereby less heat is generated in the device. A very uniform boron doping profile was achieved with-in the pSiGe gate electrode, which is critical for uniform die turn on and better thermal response for the power trench MOSFET. pSiGe thin film optimization, properties and device characteristics are discussed in details in the following sections. 相似文献
18.
Hsiao-Yi Lin Tan Fu Lei Horng-Chih Lin Chun-Yen Chang Ruey-Ching Twu Ray-Chern Deng Jandel Lin 《Solid-state electronics》1995,38(12):2029-2033
In situ boron-doped polycrystalline Si1−xGex (poly-Si1−xGex) films deposited by ultrahigh vacuum chemical vapor deposition (UHV/CVD) system were characterized. Optimum fitted values of grain boundary trap state densities, 4.0 × 1012 cm−2 and 4.9 × 1012 cm−2 were obtained for poly-Si and poly-Si0.79Ge0.21, respectively. The extracted average carrier concentration in the grain agrees with secondary ion mass spectroscopy (SIMS) analysis. In turn, we found that these films are suitable Hall elements to sense magnetic field. Experimental results show that the sensitivity decreased with the increasing input current, which can be well explained using the thermionic emission theory. Finally, we use these films to fabricate thin film transistors. 相似文献
19.
This paper reports the surface electronic structure of light-emitting porous polycrystalline silicon (PPS) using X-ray photoelectron spectroscopy (XPS). We find that the PPS films with strong photoluminescence (PL) effect can only be observed in thin film with trace amount of silicon nanoclusters and the luminescence can be enhanced remarkably with proper passivation of the PPS surface. Incomplete oxidation of silicon (Si3+ or Si2+) does not lead to visible PL. We further estimate that the average size of silicon nanoclusters is in the range of 20–30 Å in the sample having PL emission. 相似文献
20.
采用高压高功率(hphP)甚高频等离子体强强化学气相沉积(VHF-PECVD)法对微晶硅(μc-Si:H)进行高速沉积,在最优沉积条件参数下对hphP和低压低功率(lplP)两组样品沉积速率、光电导、暗电导及光敏性等性能参数进行测试,得到了1.58 nm/s的较高沉积速率、光电性能优秀和更适合薄膜太阳能电池的μc-Si... 相似文献