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1.
Bongrain A Agnès C Rousseau L Scorsone E Arnault JC Ruffinatto S Omnès F Mailley P Lissorgues G Bergonzo P 《Langmuir : the ACS journal of surfaces and colloids》2011,27(19):12226-12234
Resonant microcantilevers have demonstrated that they can play an important role in the detection of chemical and biological agents. Molecular interactions with target species on the mechanical microtransducers surface generally induce a change of the beam's bending stiffness, resulting in a shift of the resonance frequency. In most biochemical sensor applications, cantilevers must operate in liquid, even though damping deteriorates the vibrational performances of the transducers. Here we focus on diamond-based microcantilevers since their transducing properties surpass those of other materials. In fact, among a wide range of remarkable features, diamond possesses exceptional mechanical properties enabling the fabrication of cantilever beams with higher resonant frequencies and Q-factors than when made from other conventional materials. Therefore, they appear as one of the top-ranked materials for designing cantilevers operating in liquid media. In this study, we evaluate the resonator sensitivity performances of our diamond microcantilevers using grafted carboxylated alkyl chains as a tool to investigate the subtle changes of surface stiffness as induced by electrostatic interactions. Here, caproic acid was immobilized on the hydrogen-terminated surface of resonant polycrystalline diamond cantilevers using a novel one-step grafting technique that could be also adapted to several other functionalizations. By varying the pH of the solution one could tune the -COO(-)/-COOH ratio of carboxylic acid moieties immobilized on the surface, thus enabling fine variations of the surface stress. We were able to probe the cantilevers resonance frequency evolution and correlate it with the ratio of -COO(-)/-COOH terminations on the functionalized diamond surface and consequently the evolution of the electrostatic potential over the cantilever surface. The approach successfully enabled one to probe variations in cantilevers bending stiffness from several tens to hundreds of millinewtons/meter, thus opening the way for diamond microcantilevers to direct sensing applications in liquids. The evolution of the diamond surface chemistry was also investigated using X-ray photoelectron spectroscopy. 相似文献
2.
3.
J.-S. Hyun J.-H. Park J.-S. Moon J.H. Park S.H. Kim Y.J. Choi N.-E. Lee J.-H. Boo 《Progress in Solid State Chemistry》2005,33(2-4):309-315
We have tried to find the most suitable conditions for the deposition process of silicon carbide thin films as a material for MEMS techniques. We have also studied its application to semiconductor processes. To do this, we have tried to fabricate several dimensions of cantilevers with these silicon carbide thin films. High quality silicon carbide thin films are grown by metal-organic chemical vapor deposition (MOCVD). This process employs single molecular precursors such as diethylmethylsilane (DEMS), 1,3-disilabutane (DSB) at a pressure of 1 × 10−3 Pa and a growth temperature in the range of 700–1000 °C. Two fabrication methods are tested for initial fabrication of cantilevers. First, deposit SiC thin films on Si based atomic force microscopy (AFM) cantilevers. Second, used the lift-off process. To get three-dimensional cantilever-shaped SiC thin films, moreover, we chemically etched silicon substrate with strong alkaline solution such as TMAH at 80 °C. In addition, a high resolution of probe tips on the cantilevers was achieved using electron-beam deposition in a carbon atmosphere. 相似文献
4.
Yongchang Fan Alexander G. Fitzgerald Phillip John Clare E. Troupe John I. B. Wilson 《Mikrochimica acta》2000,132(2-4):435-441
The surface morphology and electronic properties of as-deposited CVD diamond films and the diamond films which have been
subjected to boron ion implantation or hydrogen plasma etching have been systematically studied by high resolution scanning
probe microscopy and spectroscopy techniques. AFM and STM image observations have shown that (a) both the as-deposited CVD
diamond films and the boron ion implanted films exhibit similar hillock morphologies on (100) crystal faces and these surface
features are formed during the deposition process; (b) boron ion implantation does not cause a discernible increase in surface
roughness; (c) atomic flatness can be achieved on crystal faces by hydrogen plasma etching of the film surface. Scanning tunnelling
spectroscopy analysis has indicated that (a) the as-deposited diamond films and the hydrogen plasma etched diamond films possess
typical p-type semiconductor surface electronic properties; (b) the as-deposited diamond films subjected to boron implantation
exhibit surface electronic properties which change from p-type semiconducting behaviour to metallic behaviour; (c) the damage
in the boron implanted diamond films is restricted to the surface layers since the electronic properties revert to p-type
on depth profiling. 相似文献
5.
Amiaud L Martin I Milosavljević AR Michaelson Sh Hoffman A Azria R Lafosse A 《Physical chemistry chemical physics : PCCP》2011,13(24):11495-11502
Electron energy loss spectrum, elastic reflectivity and selected vibrational excitation functions were measured by High Resolution Electron Energy Loss Spectroscopy (HREELS) for deuterated nanocrystalline dc GD CVD diamond films. The electron elastic reflectivity is strongly enhanced at about 13 eV, as a consequence of the second absolute band gap of diamond preserved up to the surface for D-nano-crystallites. The pure bending modes δ(CD(x)) at 88 meV and 107 meV are dominantly excited through the impact mechanism and their vibration excitation functions mimic the electron elastic reflectivity curve. Pure diamond phonon mode ν(CC) can be probed through the resolved fundamental loss located at 152 meV and through the multiple loss located at 300 meV. In addition to the well-known 8 eV resonance, two supplementary resonances located at 4.5 eV and 11.5 eV were identified and clearly resolved for the first time. A comprehensive set of data is now available on low-energy electron scattering at hydride terminated polycrystalline diamond films grown either by HF (microcrystalline) or dc GD (nanocrystalline) chemical vapour deposition. The careful comparison of the vibrational excitation functions for hydrogen/deuterium termination stretching modes ν(sp(3)-CH(x)) and ν(sp(3)-CD(x)), for hydrogen termination bending modes δ(CH(x)) mixed with diamond lattice modes ν(CC), for deuterium termination bending modes δ(CD(x)), and for multiple loss 2ν(CC) demonstrates the close interplay between three characteristics: (i) the density-of-states of the substrate, (ii) the vibrational excitation mechanisms (dipolar and/or impact scattering including resonant scattering) and (iii) the surface versus lattice character of the excited vibrational modes. This work shows clearly that excitation function measurement provides a powerful and sensitive tool to clarify loss attributions, involved excitation mechanisms, and surface versus lattice characters of the excited vibrational modes. 相似文献
6.
S. Hirata S. Inoue T-W. Kim H. Fujioka M. Oshima 《Journal of solid state chemistry》2007,180(8):2335-2339
We have demonstrated the first epitaxial growth of AlN films on single-crystalline Ta substrates by the use of a low-temperature growth technique based on pulsed laser deposition (PLD). Although previous AlN films grown on Ta(100) and (111) substrates have exhibited quite poor crystallinity, an epitaxial AlN(0001) film with an in-plane epitaxial relationship of AlN[112¯0]//Ta[001] has been obtained on a Ta(110) substrate at a growth temperature of 450 °C. We found that the full-width at half-maximum values for the crystal orientation distribution in the tilt and twist directions of the AlN film were 0.37° and 0.41°, respectively. Grazing-incidence X-ray reflection (GIXR) and X-ray photoelectron spectroscopy (XPS) measurements have revealed that the AlN/Ta heterointerface is quite abrupt, and that its abruptness remains unchanged even after annealing at 1000 °C. 相似文献
7.
Parameters controlling the removal rate of chemical vapor deposition (CVD) diamond films thermochemically polished on transition
metals in a mixed argon-hydrogen atmosphere were investigated. The ambient temperature, the pressure exerted on the diamond
film, the angular velocity of the polishing plate, the frequency and the amplitude of the transverse vibrations were among
the parameters used in the experiments. Temperature measurements showed that the removal rate was increased exponentially
with increasing magnitude of the parameter. An exponential increase in the removal rate was also observed with increasing
pressure and hence with increasing contact between the diamond film and the polishing plate. However, an exponential decrease
in the removal rate was observed with increasing angular velocity of the polishing plate. The removal rate obtained with the
application of transverse vibrations was more than three times that obtained without transverse vibrations. Moreover, the
removal rate was seen to be higher at resonant frequencies. An increase in the removal rate with increasing amplitude of the
transverse vibrations was also observed. Raman measurements carried out on the films to determine the presence of the non-diamond
carbon layer after thermochemical polishing revealed non-diamond Raman lines only for films polished at 1000 °C and 1050 °C
for the temperature range 750–1050 °C.
Received: 27 October 1999 / Accepted: 2 February 2000 相似文献
8.
Yuan Zang Lianbi Li Zhanqiang Ren Ling Cao Yan Zhang 《Surface and interface analysis : SIA》2016,48(10):1029-1032
AlN films with a preferred orientation <002> have been prepared on Si(100) substrates via DC reactive magnetron sputtering. X‐ray diffraction, atomic force microscopy, scanning electron microscopy, ellipsometer, and ultraviolet–visible–near infrared (UV–VIS–NIR) spectrophotometer were used to investigate the structural and optical properties of the AlN thin films. When the sputtering pressure is about 0.4 Pa, the flow ratio between nitrogen and argon is 1 : 3, and the growth temperature is 400 °C, the transmissivity of the AlN film is about 90% in the visible and near‐infrared region, and its optical band gap is ~5.84 eV. The refractive index of the thin films is about 2.05, which is lower than the bulk AlN refractive index. Copyright © 2016 John Wiley & Sons, Ltd. 相似文献
9.
Influence of metal electrodes on c‐axis orientation of AlN thin films deposited by DC magnetron sputtering
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Shahid Imran Jun Yuan Ge Yin Yungui Ma Sailing He 《Surface and interface analysis : SIA》2017,49(9):885-891
Nanocrystalline aluminum nitride (AlN) thin films were deposited on two types of metallic seed layers on silicon substrates, (111) textured Pt and (110) Mo, by reactive DC magnetron sputtering at low temperature (200 °C). Both textured films of Pt and Mo promote nucleation, thereby improving the crystallinity and epitaxial growth condition for AlN thin films. The deposited films were examined by X‐ray diffraction, scanning electron microscopy and atomic force microscopy techniques. The results indicated that the preferred orientation of crystallites greatly depends upon the kinetic energy of the sputtered species (target power) and seed layers used. Furthermore, AlN thin films with c‐axis perpendicular to the substrate grew on both types of metal electrodes at all power levels larger than 100 W. By comparing the structural properties and compressive stresses at perfect c‐axis orientation conditions, it is evident that AlN films deposited on (110) oriented Mo substrates exhibited superior properties as compared with Pt/Ti seed layers. Furthermore, less values of compressive stresses (?3 GPa) as compared with Pt/Ti substrates (?7.08 GPa) make Mo preferentially better candidate to be employed in the field of suspended Micro/Nano ‐ electromechanical systems (MEMS/NEMS) for piezoelectric devices. Copyright © 2017 John Wiley & Sons, Ltd. 相似文献
10.
Xin Jia Jun-jun Wei Yuechan Kong Cheng-ming Li Jinlong Liu Liangxian Chen Fangyuan Sun Xinwei Wang 《Surface and interface analysis : SIA》2019,51(7):783-790
The cooling behavior of GaN-on-diamond substrate can be enhanced by reducing the thermal boundary resistance (TBR), which is mainly determined by the nature of interlayer. Although SiN film is considered as the primary candidate of dielectric layer, it is still needed to be optimized. In order to facilitate the understanding of the influence of dielectric layer on the TBR of GaN-on-Diamond substrate, aluminum nitride (AlN), and silicon nitride (SiN) film were compared systematically, both of which are 100 nm. The time-domain thermoreflectance (TDTR) measurements, adhesion evaluation, and microstructural analysis methods were adopted to analyse these two interlayers. The results show the TBR of SiN interlayer is as low as 38.5 ± 2.4 m2K GW−1, comparing with the value of 56.4 ± 5.5 m2K GW−1 for AlN interlayer. The difference of TBR between these two interlayers is elucidated by the diamond nucleation density, and the adhesion between the diamond film and GaN substrate, both of which are affected by the surface charge and chemical groups of the dielectric layer. 相似文献
11.
Incorporating two-dimensional (2-D) boron nitride (BN) into polyimide/aluminum nitride (PI/AlN) renders a simple strategy in producing new ternary composite films with longer corona aging life and higher breakdown strength compared with PI/AlN. During corona aging process, the effects of 2-D BN on adjusting the microstructure evolution of ternary composites were investigated using quasi-in-situ technology systematically as follow: (SEM), (AFM), (FTIR), (XRD) and (SAXS) at different corona time. Quasi-in-situ characterization results show that the corona aging modes of the two composite films are quite different, the introduction of BN nanosheets could protect the C–N–C and C–O–C bonds from breaking as well as accelerate the fillers expose via autoxidation reaction. In addition, BN nanosheets could induce the distance between PI molecular chains to shorten during the corona process, resulting in more dense structures coordinating with AlN and PI. Different corona aging mechanism compared with that of the PI/AlN composite films was proposed. This work demonstrated the effect of 2-D BN nanosheets in the PI/AlN+BN ternary composites, which can be used to expand their application in insulating polymer based composites. 相似文献
12.
Xiuting Jin Fengbin Liu Lina Si Zhaoliang Dou Hongjuan Yan Hong Li Min Qu 《Surface and interface analysis : SIA》2019,51(11):1044-1050
To elucidate the influence of different terminations on diamond surface interaction, the geometry and electronic structures of the diamond films modified by different terminations (H, F, O, NH2, and OH) are studied by using the first principles method. Strong bonding is formed between the clean diamond surfaces, which suggest an obvious interface interaction. Both H and F terminals have significant effects on the reduction of the interface interactions. Due to the larger difference in electronegativity between C and F, the F termination layer has a higher electron density coverage to give a larger repulsive force. Therefore, the interaction between the F-terminated diamond interfaces is stronger than that between the H-terminated diamond interfaces. The O-terminated diamond surfaces are unstable. The NH2- and OH-terminals have weak interaction due to the presence of large functional group atoms that leads to an electronic offset. 相似文献
13.
Alexander G. Fitzgerald Yongchang Fan Phillip John Clare E. Troupe John I. B. Wilson Anthony O. Tooke Brian E. Storey 《Mikrochimica acta》2000,132(2-4):315-321
The characteristics of the interface microstructures between a CVD diamond film and the silicon substrate have been studied
by transmission electron microscopy and electron energy loss spectroscopy. The investigations are performed on plan-view TEM
specimens which were intentionally thinned only from the film surface side allowing the overall microstructural features of
the interface to be studied. A prominent interfacial layer with amorphous-like features has been directly observed for CVD
diamond films that shows a highly twinned defective diamond surface morphology. Similar interfacial layers have also been
observed on films with a <100> growth texture but having the {100} crystal faces randomly oriented on the silicon substrate.
These interfacial layers have been unambiguously identified as diamond phase carbon by both electron diffraction and electron
energy loss spectroscopy. For the CVD diamond films that exhibit heteroepitaxial growth features, with the {100} crystal faces
aligned crystallographically on the silicon substrate, such an interfacial layer was not observed. This is consistent with
the expectation that the epitaxial growth of CVD diamond films requires diamond crystals to directly nucleate and grow on
the substrate surface or on an epitaxial interface layer that has a small lattice misfit to both the substrate and the thin
film material. 相似文献
14.
研究了电子辅助热灯丝法生长金刚石厚膜过程中氢气流量对沉积速度和膜品质的影响。随氢气流量从100增加到750cm^3/min,金刚石膜的沉积速率单调上升,但金刚石膜品质不断下降,从750到1000cm^3/min,金刚石膜沉积速率下降,但金刚石膜品质随氢气流量增加而提高。拉曼光谱和电子顺磁共振谱研究发现,在所制备的金刚石膜中含有替代形式的氮,氮含量随氢气流量的增加而减小,1000cm^3/min流量下沉积的金刚石膜的含氮量仅为100cm^3/min流量下沉积的金刚石膜的1/40。 相似文献
15.
Zhang WJ Meng XM Chan CY Chan KM Wu Y Bello I Lee ST 《The journal of physical chemistry. B》2005,109(33):16005-16010
We have studied the nucleation and growth of cubic boron nitride (cBN) films deposited on silicon and diamond-coated silicon substrates using fluorine-assisted chemical vapor deposition (CVD). These comparative studies substantiate that the incubation amorphous/turbostratic BN layers, essential for the cBN nucleation on silicon, are not vital precursors for cBN nucleation on diamond, and they are inherently eliminated. At vastly reduced critical bias voltage, down to -10 V, cBN growth is still maintained on diamond surfaces, and cBN and underlying diamond crystallites exhibit an epitaxial relationship. However, the epitaxial growth is associated with stress in the cBN-diamond interfacial region. In addition, some twinning of crystallites and small-angle grain boundaries are observed between the cBN and diamond crystallites because of the slight lattice mismatch of 1.36%. The small-angle grain boundaries could be eliminated by imposing a little higher bias voltage during the initial growth stage. The heteroepitaxial growth of cBN films on different substrate materials are discussed in the view of lattice matching, surface-energy compatibility, and stability of the substrate against ion irradiation. 相似文献
16.
Caruso T Lenardi C Agostino RG Amati M Bongiorno G Mazza T Policicchio A Formoso V Maccallini E Colavita E Chiarello G Finetti P Sutara F Skála T Piseri P Prince KC Milani P 《The Journal of chemical physics》2008,128(9):094704
The electronic structure of cluster assembled nanostructured TiO(2) thin films has been investigated by resonant photoemission experiments with photon energies across the Ti L(2,3) edge. The samples were produced by supersonic cluster beam deposition with a pulsed microplasma cluster source. The valence band shows resonance enhancements in the binding energy region between 4 and 8 eV, populated by O 2p and hybridized Ti 3d states, and in the region about 1 eV below the Fermi level associated with defects related Ti 3d states. The data show that in as-deposited films Ti atoms are mainly fully (sixfolds) coordinated to oxygen atoms in octahedral symmetry and only a small fraction is in a broken symmetry environment. Since resonant photoemission is closely linked to the local electronic and structural configurations around the Ti atom, it is possible to correlate the resonant photoemission intensity and lineshape with the presence of defects of the films and with the degree of hybridization between the titanium and oxygen atoms. 相似文献
17.
V. A. Tarala B. M. Sinel’nikov 《Russian Journal of Physical Chemistry A, Focus on Chemistry》2012,86(4):658-663
The nucleation and growth processes of amorphous and crystalline films of diamond-like materials deposited on the (100) planes
of monocrystals with a diamond structure of diamond are modeled. The mechanisms of the formation of monolayers are analyzed
from the results of calculating the potential energies of carbon clusters by means of modern semiempirical quantum chemical
methods of computer chemistry. The nucleation and growth of an epitaxial film is considered as a replication process, and
the deposition of amorphous films is described from the viewpoint of modifying the surface superstructure. Equations establishing
the relationship between the structure of amorphous and crystalline films and conditions of the synthesis are obtained as
a result of the performed studies. 相似文献
18.
Effect of pressure on the growth of boron and nitrogen doped HFCVD diamond films on WC–Co substrate
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Liang Wang Bin Shen Fanghong Sun Zhiming Zhang 《Surface and interface analysis : SIA》2015,47(5):572-586
Boron and nitrogen compounds are added in the acetone/hydrogen gas mixture to deposit hot filament chemical vapor deposition (HFCVD) diamond films on the cobalt cemented tungsten carbide (WC–Co) substrate under the pressure of 1–4 kPa. The as‐deposited diamond films are characterized by field emission scanning electron microscope (FESEM), atomic force microscopy (AFM), X‐ray diffraction (XRD) spectroscopy and Raman spectroscopy. The results reveal that the surface morphology, growth rate, structure and quality of the diamond films vary with the pressure and the type of the impurity addition. The diamond grains tend to develop into the nanometer scale with the decrease of the pressure. However, adding of boron or nitrogen impurities in the gas mixture will weaken the nanocrystallization effect by reducing the carbon supersaturation. Density functional theory (DFT) calculations indicate that co‐adsorption of B and N containing radicals can favor the adsorption of CH3 on diamond (100) surface. Thus, at low pressure of 1 kPa, large grained cubic (100) facet diamond rather than typical nanometer diamond is produced for B–N co‐addition gas mixture. The present results appear to be useful to efficiently synthesize high quality doped diamonds with desirable properties for mechanical application. Copyright © 2015 John Wiley & Sons, Ltd. 相似文献
19.
氮化铝薄膜的组成分析 总被引:2,自引:0,他引:2
Al N是一种无机非铁性压电材料 ,具有宽的带隙、高的电阻率、高的抗击穿电压、高的声传播速率和低的传输损耗 ,在微电子器件中有着广泛的应用前景 [1] .由于 Al N薄膜的声速在整个无机非铁性材料中最高 ,因而成为 GHz级声表面波器件的首选材料 [2 ] .要实现 Al N薄膜的表面声波器件应用 ,不但结构重要 [1] ,组成也很重要 [3] ,因为薄膜的组成对其性质影响很大 .Al N压电薄膜要求整个膜层的 Al/N比一致 .富 Al会使薄膜介电性能变差 ,富 N会使薄膜结构致密度变差 .因而对其组成研究是非常重要的 .Penza等 [3] 采用X射线光电子能谱 ( X… 相似文献