共查询到20条相似文献,搜索用时 31 毫秒
1.
Formation of Au nano-patterns on various substrates using simplified nano-transfer printing method 总被引:1,自引:0,他引:1
Jong-Woo Kim 《Applied Surface Science》2008,254(17):5607-5611
For future device applications, fabrication of the metal nano-patterns on various substrates, such as Si wafer, non-planar glass lens and flexible plastic films become important. Among various nano-patterning technologies, nano-transfer print method is one of the simplest techniques to fabricate metal nano-patterns. In nano-transfer printing process, thin Au layer is deposited on flexible PDMS mold, containing surface protrusion patterns, and the Au layer is transferred from PDMS mold to various substrates due to the difference of bonding strength of Au layer to PDMS mold and to the substrate. For effective transfer of Au layer, self-assembled monolayer, which has strong bonding to Au, is deposited on the substrate as a glue layer.In this study, complicated SAM layer coating process was replaced to simple UV/ozone treatment, which can activates the surface and form the -OH radicals. Using simple UV/ozone treatments on both Au and substrate, Au nano-pattern can be successfully transferred to as large as 6 in. diameter Si wafer, without SAM coating process. High fidelity transfer of Au nano-patterns to non-planar glass lens and flexible PET film was also demonstrated. 相似文献
2.
3.
Shu-Chia Shiu 《Applied Surface Science》2009,255(20):8566-8570
Si nanowires (NWs) are promising materials for future electronic, photovoltaic, and sensor applications. So far the Si NWs are mainly formed on particular substrates or at high temperatures, greatly limiting their application flexibility. Here we report a low temperature process for forming and massively transferring vertically aligned Si NWs on alien substrates with a large density of about (3-5) × 107 NWs/mm2. The X-ray diffraction spectrum reveals that the transferred NWs exhibit almost the same crystal property as the bulk Si. Our investigation further shows that the transferred NWs have exceptional optical characteristics. The transferred Si NWs of 12.14 μm exhibit the transmittance as low as 0.3% in the near infrared region and 0.07% in the visible region. The extracted absorption coefficient of Si NWs in the near infrared region is about 3 × 103 cm−1, over 30 times larger than that of the bulk Si. Because of the low temperature process, it enables a large variety of alien substrates such as glass and plastics to be used. In addition, the exceptional properties of the transferred NWs offer potential applications for photovoltaic, photo-detectors, sensors, and flexible electronics. 相似文献
4.
Isamu Miyamoto Kristian Cvecek Yasuhiro Okamoto Michael Schmidt 《Applied Physics A: Materials Science & Processing》2014,114(1):187-208
Internal modification process of glass by ultrashort laser pulse (USLP) and its applications to microwelding of glass are presented. A simulation model is developed, which can determine intensity distribution of absorbed laser energy, nonlinear absorptivity and temperature distribution at different pulse repetition rates and pulse energies in internal modification of bulk glass with fs- and ps-laser pulses from experimental modified structure. The formation process of the dual-structured internal modification is clarified, which consists of a teardrop-shaped inner structure and an elliptical outer structure, corresponding to the laser-absorbing region and heat-affected molten region, respectively. Nonlinear absorptivity at high pulse repetition rates increases due to the increase in the thermally excited free electron density for avalanche ionization. USLP enables crack-free welding of glass because the shrinkage stress is suppressed by producing embedded molten pool by nonlinear absorption process, in contrast to conventional continuous wave laser welding where cracks cannot be avoided due to shrinkage stress produced in cooling process. Microwelding techniques of glass by USLP have been developed to join glass/glass and Si/glass using optically contacted sample pairs. The strength of the weld joint as high as that of base material is obtained without pre- and post-heating in glass/glass welding. In Si/glass welding, excellent joint performances competitive with anodic bonding in terms of joint strength and process throughput have been attained. 相似文献
5.
Al-Induced Crystallization Growth of Si Films by Inductively Coupled Plasma Chemical Vapour Deposition
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Polycrystalline Si (poly-Si) films are in situ grown on Al-coated glass substrates by inductively coupled plasma chemical vapour deposition at a temperature as low as 350℃. Compared to the traditional annealing crystalliza- tion of amorphous Si/Al-layer structures, no layer exchange is observed and the resultant poly-Si film is much thicker than Al layer. By analysing the depth profiles of the elemental composition, no remains of A1 atoms are detected in Si layer within the limit (〈0.01 at.%) of the used evaluations. It is indicated that the poly-Si material obtained by Al-induced crystallization growth has more potential applications than that prepared by annealing the amorphous Si/Al-layer structures. 相似文献
6.
Silicon/polyaniline-based porous carbon (Si/PANI-AC) composites have been prepared by a three-step method: coating polyaniline on Si particles using in situ polymerization, carbonizing, and further activating by steam. The morphology and structure of Si/PANI-AC composites have been characterized by scanning electron microscopy, transmission electron microscopy, X-ray diffraction, and Raman spectra, respectively. The content and pore structure of the carbon coating layer in Si/PANI-AC have been measured by thermogravimetric analysis and N2 adsorption-desorption isotherm, respectively. The results indicate some micropores about 1~2 nm in the carbon layer appear during activation and that crystal structure and morphology of Si particles can be retained during preparation. Si/PANI-AC composites exhibit high discharge capacity about 1000 mAh g?1 at 1.5 A g?1; moreover, when the current density returns to 0.2 A g?1, the discharge capacity is still 1692 mAh g?1 and remains 1453 mAh g?1 after 70 cycles. The results indicate that the porous carbon coating layer in composites plays an important role in the improvement of the electrochemical performance of pure Si. 相似文献
7.
Shantanu Bhattacharya Yuanfang Gao M.T. Othman Shubhra Gangopadhyay 《Applied Surface Science》2007,253(9):4220-4225
Silicone polymer (PDMS), widely used for micro-fluidic and biosensor applications, possesses an extremely dynamic surface after it is subjected to an oxygen plasma treatment process. The surface becomes extremely hydrophilic immediately after oxygen plasma exposure by developing silanol bond (SiOH), which promotes its adhesion to some other surfaces like, silicon, silicon dioxide, glass, etc. Such a surface, if left in ambient dry air, shows a gradual recovery of hydrophobicity. We have found an identical behavior to occur to surfaces coated with a thin continuous film of SOG (methyl silsesquioxane). The chemistry induced by oxygen plasma treatment of a spin-on-glass (SOG) coated surface provides a much higher density of surface silanol groups in comparison to precleaned glass, silicon or silicon dioxide substrates thus providing a higher bond strength with polydimethyl siloxane (PDMS). The bonding protocol developed by using the spin coated and cured SOG intermediate layer provides an universal regime of multi level wafer bonding of PDMS to a variety of substrates. The paper describes a contact angle based estimation of bond strength for SOG and PDMS surfaces exposed to various combinations of plasma parameters. We have found that the highest bond strength condition is achieved if the contact angle on the SOG surface is less than 10°. 相似文献
8.
The microwave spectrum of trimethylbromosilane (trimethylsilylbromide) has been investigated in the 26.5–40.0-GHz region. Spectra of several isotopic species have been observed, including the previously unreported spectrum of the 1H12C30Si81Br species, which yielded a B rotational constant of 1440.92 ± 0.02 MHz. From the experimental data it has been possible to derive the following structural parameters: SiBr = 2.235 ± 0.002 Å, SiC = 1.856 ± 0.010 Å, and ∠CSiBr = 107.5 ± 0.1°. The results have been compared to other relevant data and discussed in terms of prevailing chemical bonding principles. 相似文献
9.
M. Mamor Y. Fu O. Nur M. Willander S. Bengtsson 《Applied Physics A: Materials Science & Processing》2001,72(5):633-637
We investigate, both experimentally and theoretically, current and capacitance (I–V/C–V) characteristics and the device performance
of Si/SiO2/Si single-barrier varactor diodes (SBVs). Two diodes were fabricated with different SiO2 layer thicknesses using the state-of-the-art wafer bonding technique. The devices have very low leakage currents (about 5×10-2 and 1.8×10-2 mA/mm2) and intrinsic capacitance levels of typically 1.5 and 50 nF/mm2 for diodes with 5-nm and 20-nm oxide layers, respectively. With the present device physical parameters (25-mm2 device area, 760-μm modulation layer thickness and ≈1015-cm-3 doping level), the estimated cut-off frequency is about 5×107 Hz. With the physical parameters of the present existing III–V triplers, the cut-off frequency of our Si-based SBV can be
as high as 0.5 THz.
Received: 9 February 2001 / Accepted: 9 February 2001 / Published online: 23 March 2001 相似文献
10.
Heterojunction light-emitting diodes with ZnO/Si structure were fabricated on both high-resistivity (p) and low-resistivity (p+) Si substrates by metal-organic chemical vapor deposition technology. Fairly good rectifications were observed from the current-voltage curves of both heterojunctions. Ultraviolet (UV) and blue-white electroluminescence (EL) from ZnO layer were observed only from ZnO/p+-Si heterojunction under forward bias at room temperature (RT), while strong infrared (IR) EL emissions from Si substrates were detected from both ZnO/p-Si and ZnO/p+-Si heterojunctions. The UV and IR EL mechanisms have been explained by energy band structures. The realization of RT EL in UV-visible and IR region on Si substrate has great applicable potential for Si-based optoelectronic integrated circuits. 相似文献
11.
Sanghee Cho 《Surface science》2004,565(1):14-26
In order to understand the atomic structure of nanostructures self-assembled on the template with one-dimensional symmetry, Bi/Si(5 5 12) system has been chosen and Bi-adsorption steps have been studied by STM. With Bi adsorption, the clean Si(5 5 12) is transformed to (3 3 7) terraces with disordered boundary due to mismatched periodicities between (3 3 7) and (5 5 12), and Bi-dimer rows are formed inside the (3 3 7) unit as follows: Initially, when Bi atoms are deposited at the adsorption temperature of about 450 °C, they selectively replace Si-dimers and Si-adatoms and form adsorbed Bi-dimers and Bi-adatoms, respectively. If additional Bi is supplied, the Bi-dimers adsorb on the Bi-dimers and Bi-adatoms in the first layer. These adsorbed dimers in the second layer are facing each other to form a Bi-dimer pair with relatively stable p3bonding. Finally, a single Bi-dimer adsorbs above the Bi-dimer pair in the second layer, at which point the Bi layer thickness saturates. It has been concluded that the Bi-dimer pair with stable p3 bonding is the composing element in the second layer and such site-selective adsorption is possible due to the substrate-strain relaxation through inserting Bi-buffer layer limited to specific sites of the substrate. 相似文献
12.
Transition to single crystal of polycrystalline Si material underlying a Si crystal substrate of 〈100〉 orientation was obtained
via laser irradiation. The changes in the structure were analyzed by reflection high energy electron diffraction and by channeling
effect technique using 2.0 MeV He Rutherford scattering. The power density required to induce the transition in a 4500 ? thick
polycrystalline layer is about 70 MW/cm2 (50ns). The corresponding amorphous to single transition has a threshold of about 45 MW/cm2. 相似文献
13.
Ke-Ming Wang Bo-Rong Shi Xiang-Dong Liu Tian-Bing Xu Pei-Ran Zhu Jun-Si Zhu Qing-Tai Zhao 《Applied Physics A: Materials Science & Processing》1992,55(4):332-334
The effect of 2.0 MeV Cu+ irradiation on Si(100) crystal has been studied by the Rutherford backscattering/channeling technique. Analysis of the lattice disorder distribution has been performed under 100 direction of tilting off from the target normal: 7°, 30°, and 45° as well as different doses. The lattice disorder distributions in Si(100) have been compared with TRIM'89 simulation. The results show that the lattice disorder distributions in Si(100) under different irradiation angles seem to be in good agreement with TRIM'89 simulation. When the dose increases up to 8.7×1014 ions/cm2, the defect concentration increases leading to the formation of an amorphous layer. 相似文献
14.
Hongbo Li C. H. M. van der Werf A. Borreman J. K. Rath Ruud E. I. Schropp 《固体物理学:研究快报》2008,2(4):157-159
In this letter we report the result of an a‐Si:H/nc‐Si:H tandem thin film silicon solar mini‐module fabricated on plastic foil containing intrinsic silicon layers made by hot‐wire CVD (efficiency 7.4%, monolithically series‐connected, aperture area 25 cm2). We used the Helianthos cell transfer process. The cells were first deposited on a temporary aluminum foil carrier, which allows the use of the optimal processing temperatures, and then transferred to a plastic foil. This letter reports the characteristics of the flexible solar cells obtained in this manner, and compares the results with those obtained on reference glass substrates. The research focus for implementation of the hot‐wire CVD technique for the roll‐to‐roll process is also discussed. (© 2008 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim) 相似文献
15.
Dong Nyung Lee 《Journal of Physics and Chemistry of Solids》2011,72(11):1330-1333
When amorphous silicon films deposited on glass by physical or chemical vapor deposition are annealed, they undergo crystallization by nucleation and growth. The growth rate of Si crystallites is the highest in their 〈111〉 directions along or nearly along the film surface. The directed crystallization is likely to develop the 〈110〉//ND or 〈111〉//ND oriented Si crystallites. As the annealing temperature increases, the equiaxed crystallization increases, which in turn increases the random orientation. When amorphous Si is under a stress of the order of 0.1 GPa at about 540 °C, the tensile stress increases the growth rate of Si grains, whereas the compressive stress decreases the growth rate. However, the crystal growth rate increases with the increasing hydrostatic pressure, when the pressure is of the order of GPa at 530–540 °C. These phenomena have been discussed based on the directed crystallization model advanced before, which has been further elaborated. 相似文献
16.
The Pr3+doped PbO-GeO2 glass samples have been synthesized by melting and quenching process. The nephelauxetic ratio, covalency and bonding parameter
which provides the information about the type of bonding between the rare earth ion and neighbor oxygen atoms calculated.
The optical parameters such as radiative transition probabilities, radiative lifetime, branching ratios etc. of Pr3+ ions have been determined by Judd-Ofelt analysis. An upconversion emission using the excitation at ~594 nm supported by energy
transfer process due to dipole-dipole interaction in the 1D2 metastable state has been found. 相似文献
17.
Low-energy electron diffraction (LEED) and Auger electron spectroscopy (AES) have been used to study the initial stages of the nitridation of silicon. Most of the experiments involved pressures of 10?5?10?7 torr of ammonia and silicon temperatures in the range 800–1100°C. An earlier study of the nitridation of the Si (111) surface, has been extended to allow comparison between the (111), (311) and (100) faces of silicon. These surfaces provide a series of unit meshes with different shapes and symmetries while retaining some common geometrical features. Of particular interest for epitaxial theory is the growth of an impurity induced nitride structure, which is common to both Si(111) and Si (311). This may be explained if the nucleation and orientation of the niti ide are determined by the geometry of localised sites, common to both substrates. Subsequent growth of the nitride layer is then dominated by intra-layer bonding, so that the difference in substrate symmetries has little effect. 相似文献
18.
PbO-PbF2-B2O3 glasses containing different concentrations of FeO have been prepared. The glasses are characterized by X-ray diffraction and differential thermal analysis. The dielectric properties viz., dielectric constant, loss, conductivity, over a moderately wide range of frequency and temperature and dielectric breakdown strength have been investigated. The results of these studies have been analyzed in the light of different oxidation states of iron with the aid of the data on IR, ESR, optical absorption and magnetic susceptibility measurements. The analysis shows that iron ions exist mainly in Fe3+ state, occupy tetrahedral positions and increase the insulating strength of the glass if FeO is present in smaller concentrations. However, if FeO is present in higher concentrations in the glass matrix, (i) the dielectric relaxation intensity has been observed to increase, (ii) the intensity and the half width of the ESR signal has been observed to decrease and (iii) the value of magnetic moment (evaluated from magnetic susceptibility) has been observed to drop to a value of 4.6 μB from 5.7 μB. From these results it has been concluded that in this concentration range, iron ions exist mainly in divalent state. 相似文献
19.
M. Waris 《Applied Surface Science》2006,252(20):7327-7330
This work demonstrates anodic bonding of Zerodur glass having very low co-efficient of thermal expansion (CTE) to Si, Zerodur glass to thermally grown silicon dioxide on silicon and Pyrex glass to Ge. Bonding results, using point cathode contact and plate cathode contact configurations, are discussed. Bonding parameters, i.e. applied dc voltage, temperature and bonding time were determined. Heating and cooling rates for crack-free bonding of Zerodur glass were also determined. 相似文献
20.
E. Landi A. Armigliato S. Solmi R. Kögler E. Wieser 《Applied Physics A: Materials Science & Processing》1988,47(4):359-366
The electrical activation of boron implanted in crystalline and preamorphized silicon has been investigated during rapid thermal
annealing performed with halogen lamps. Samples implanted with B+ fluences ranging between 5×1014 and 1×1016cm−2 and treated at temperatures between 900°C and 1100°C have been examined. When boron is implanted in crystalline Si, activation
proceeds slowly atT<1000°C and cannot be completed in times typical of rapid thermal annealing (a few tens of seconds). The analysis of carrier
profiles indicates that the time constant for activation is strongly affected by local damage and dopant concentration. If
the total boron concentration exceeds equilibrium solubility, precipitation occurs concomitant to activation, even if the
substitutional boron fraction is still lower than equilibrium solubility. ForT≧1000°C complete activation is obtained in times of about 10 s. In the case of preamorphized Si the activation occurs very
quickly, during the recrystallization of the amorphous layer, for all the examined temperatures. 相似文献