共查询到20条相似文献,搜索用时 31 毫秒
1.
Hongliang Zhang Weidong Wu Chengshi Gong Wei Wang Zhibing He Jun Li Xin Ju Yongjian Tang Erqing Xie 《Applied Physics A: Materials Science & Processing》2010,98(4):895-900
Fe-doped hydrogenated amorphous carbon (a-C:H:Fe) films were deposited from a gas mixture of trans-2-butene/ferrocene/H2 by plasma enhanced metal organic chemical vapor deposition. X-ray photoelectron spectroscopy, Fourier transform infrared
spectra and Raman spectra were used to characterize the composition and the bonding structure of the a-C:H:Fe and a-C:H films.
Optical properties were investigated by the UV–visible spectroscopy and the photoluminescence (PL) spectra. The Fe-doped films
contain more aromatic structures and C=C bonds than the undoped films. The sp
2 carbon content and sp
2 clustering of the films increase, and aromatic-like rings’ structures become richer after Fe-doping. The Tauc optical gap
of the a-C:H:Fe films become narrower by 0.3 eV relative to the value of the a-C:H films. The PL peak shifts from 2.35 eV
of the a-C:H films to 1.95 eV of the a-C:H:Fe films, and the PL intensity of the a-C:H:Fe films is greatly enhanced. A deep
level emission peak around 2.04 eV of the a-C:H:Fe films is observed. 相似文献
2.
The a-C:H and a-C:NX:H films were deposited onto silicon wafers using radio frequency (rf) plasma enhanced chemical vapor deposition (PECVD) and pulsed-dc glow discharge plasma CVD, respectively. Raman spectroscopy and X-ray photoelectron spectroscopy (XPS) were used to characterize chemical nature and bond types of the films. The results demonstrated that the a-C:H film prepared by rf-CVD (rf C:H) has lower ID/IG ratio, indicating smaller sp2 cluster size in an amorphous carbon matrix. The nitrogen concentrations of 2.9 at.% and 7.9 at.% correspond to carbon nitride films prepared with rf and pulse power, respectively.Electrochemical corrosion performances of the carbon films were investigated by potentiodynamic polarization test. The electrolyte used in this work was a 0.89% NaCl solution. The corrosion test showed that the rf C:H film exhibited excellent anti-corrosion performance with a corrosion rate of 2 nA cm−2, while the carbon nitride films prepared by rf technique and pulse technique showed a corrosion rate of 6 nA cm−2 and 235 nA cm−2, respectively. It is reasonable to conclude that the smaller sp2 cluster size of rf C:H film restrained the electron transfer velocity and then avoids detriment from the exchange of electrons. 相似文献
3.
A. von Keudell M. Meier T. Schwarz-Selinger 《Applied Physics A: Materials Science & Processing》2001,72(5):551-556
Methyl radicals (CH3) and atomic hydrogen (H) are dominant radicals in low-temperature plasmas from methane. The surface reactions of these radicals
are believed to be key steps leading to deposition of amorphous hydrogenated carbon (a-C:H) films or polycrystalline diamond
in these discharges. The underlying growth mechanism is studied, by exposing an a-C:H film to quantified radical beams of
H and CH3. The deposition or etching rate is monitored via ellipsometry and the variation of the stoichiometry is monitored via isotope
labeling and infrared spectroscopy. It was shown recently that, at 320 K, methyl radicals have a sticking coefficient of 10-4 on a-C:H films, which rises to 10-2 if an additional flux of atomic hydrogen is present. This represents a synergistic growth mechanism between H and CH3. From the interpretation of the infrared data, a reaction scheme for this type of film growth is developed: atomic hydrogen
creates dangling bonds by abstraction of bonded hydrogen within a surface layer corresponding to the range of H in a-C:H films.
These dangling bonds serve at the physical surface as adsorption sites for incoming methyl radicals and beneath the surface
as radicalic centers for polymerization reactions leading to carbon–carbon bonds and to the formation of a dense a-C:H film.
Received: 18 July 2000 / Accepted: 12 December 2000 / Published online: 3 April 2001 相似文献
4.
L.M. Zambov C. Popov M.F. Plass A. Bock M. Jelinek J. Lancok K. Masseli W. Kulisch 《Applied Physics A: Materials Science & Processing》2000,70(5):603-606
The humidity sensitive properties of carbon nitride (CNx) films deposited by two methods, inductively coupled plasma chemical vapour deposition utilizing transport reactions and
pulsed laser deposition combined with an rf discharge, have been investigated. For this purpose capacitance humidity sensors
with a CNx detecting element have been fabricated and tested. Fast and significant responses toward moisture are registered by the changes
of the electrical parameters. The CNx films sensing mechanism has been discussed. The results obtained show unambiguously that CNx films appear to be a promising candidate as a humidity sensitive element in up-to-date electronic noses.
Received: 6 December 1999 / Accepted: 7 January 2000 / Published online: 24 March 2000 相似文献
5.
Z. F. Li Z. Y. Yang R. F. Xiao 《Applied Physics A: Materials Science & Processing》1996,63(3):243-246
Visible photoluminescence (PL) has been observed from the hydrogenated amorphous carbon (a-C:H) films prepared by ArF pulsed laser ablation of polymethyl methacrylate (PMMA) in the presence of hydrogen gas (H2). With increasing hydrogen concentration the PL intensity increases and the intensity maximum blue-shifted. The PL intensity also increases after hours of light illumination, exhibiting a light soaking enhancement. Increasing the deposition temperature decreases the PL and increases the ratio of sp3/sp2 bonds.Z.F. Li is on leave from Department of Physics, Nanjing University, Nanjing 210093, P.R. China. 相似文献
6.
A systematic study of the chemical bonding in hydrogenated amorphous germanium–carbon (a-Ge1-xCx:H)alloys using X-ray photoelectron spectroscopy (XPS) is presented. The films, with carbon content ranging from 0 at. % to
100 at. %, were prepared by the rf co-sputtering technique. Raman spectroscopy was used to investigate the carbon hybridization.
Rutherford backscattering spectroscopy (RBS) and XPS were used to determine the film stoichiometry. The Ge 3d and C 1s core
levels were used for investigating the bonding properties of germanium and carbon atoms, respectively. The relative concentrations
of C–Ge, C–C, and C–H bonds were calculated using the intensities of the chemically shifted C 1s components. It was observed
that the carbon atoms enter the germanium network with different hybridization, which depends on the carbon concentration.
For concentrations lower than 20 at. %, the carbon atoms are preferentially sp3 hybridized, and approximately randomly distributed. As the carbon content increases the concentration of sp2 sites also increases and the films are more graphitic-like.
Received: 4 May 1999 / Accepted: 24 November 1999 / Published online: 24 March 2000 相似文献
7.
We investigated the photoluminescence (PL) properties of carbon nitride films (CNx) deposited by rf magnetron sputtering and compared them to their microstructure depending on the target self-bias. While many of the data are compatible with ‘a-C:H like’ PL properties the observed variation of the PL efficiency η with respect to the target bias cannot be easily explained by the standard models. It is suggested that the observed variation of η is rather dominated by a change in microstructure which depends on the bombardment intensity during growth than by the concentration of non-radiative centres. 相似文献
8.
Strong ultraviolet and violet photoluminescence from Si-based anodic porous alumina films 总被引:5,自引:0,他引:5
J.H. Wu X.L. Wu N. Tang Y.F. Mei X.M. Bao 《Applied Physics A: Materials Science & Processing》2001,72(6):735-737
We have investigated photoluminescence (PL) from Si-based anodic porous alumina films formed by real-time controlled anodization
of electron-beam evaporated Al films. As-anodized samples show three strong PL bands at 295, 340, and 395 nm. These bands
blueshift and their intensities decrease after the samples are annealed. When the annealing temperature increases to 1000 °C,
the blueshift becomes specially pronounced and meanwhile the structures of the films develop toward crystalline Al2O3. Based on discussions on the thermal annealing behaviors of the PL and PL excitation spectra, we suggest that optical transitions
in oxygen-related defects, F+ (oxygen vacancy with one electron) centers, are responsible for the observed ultraviolet and violet PL.
Received: 24 July 2000 / Accepted: 24 February 2001 / Published online: 3 May 2001 相似文献
9.
P. Špatenka H. Suhr G. Erker M. Rump 《Applied Physics A: Materials Science & Processing》1995,60(3):285-288
Thin films of hafnium carbide have been deposited by plasma-enhanced chemical vapor deposition using bis(-cyclopentadienyl)dimethylhafnium, Cp2 Hf(CH3)2, as precursor in 13.56 MHz planar reactor. The influence of the various experimental parameters on film properties has been studied. The carbon content ranged from 11 to 40 weight % and increased with the deposition rate. The film hardness varied between 1300 and 2000 HK. Depending on the carbon content and power delivered in the discharge, the film resistivity and film density ranged from 271 to 105 ·cm and from 3.4 to 10.4 g/cm3, respectively, and the film composition varied from HfC to hafnium containing a-C: H films. 相似文献
10.
采用射频(rf)激发,在热丝化学气相沉积(HWCVD)制备微晶硅薄膜的过程中产生发光基元,测量了rf激发HWCVD (rf-HWCVD)的光发射谱,比较了相同工艺条件下rf-HWCVD和等离子体增强CVD(PECVD)的光发射谱,分析了rf功率、热丝温度和沉积气压对rf-HWCVD光发射谱的影响.结果表明,在射频功率<0.1W/cm2时,rf-HWCVD发射光谱反映了HWCVD高的气体分解效率和高浓度原子氢的特点,能够解释气压变化与微晶硅薄膜微结构的关系,是研究HWCVD气相过程的有
关键词:
HWCVD
OES
微晶硅 相似文献
11.
Z.Y. Chen J.P. Zhao T. Yano T. Ooie 《Applied Physics A: Materials Science & Processing》2002,75(2):213-216
Raman characteristics of carbon nitride films synthesized by nitrogen-ion-beam-assisted pulsed laser deposition were investigated.
In addition to the D (disorder) band and G (graphitic) band commonly observed in carbon nitride films, two Raman bands located
at 1080–1100 and 1465–1480 cm-1 were found from our carbon nitride films. These two bands were well matched with the predicted Raman frequencies for βC3N4 and the observed Raman bands reported for carbon nitride films, indicating their relation to carbon-nitrogen stretching vibrations.
Furthermore, the relative intensity ratio of the two Raman bands to the D and G bands increased linearly with increasing nitrogen
content of the carbon nitride films.
Received: 30 October 2000 / Accepted: 5 February 2001 / Published online: 2 October 2001 相似文献
12.
采用等离子体增强化学气相沉积技术沉积一系列处于不同生长阶段的微晶硅薄膜.通过同步辐射X射线掠角反射技术研究微晶硅薄膜的表面粗糙度随时间等的演化,探讨微晶硅薄膜的生长动力学过程及其生长机制.研究结果表明,在衬底温度为200 ℃,电极间距为2 cm,沉积气压为6.66×102 Pa,射频功率密度为0.22 W/cm2,氢稀释度分别为99%和98%的沉积条件下,在玻璃衬底上生长的微晶硅薄膜生长指数β分别为0.21±0.01和0.24±0.01.根据KPZ模型,微晶硅薄膜的生长机制为有限扩散生长.
关键词:
X射线掠角反射
微晶硅薄膜
表面粗糙度
生长机制 相似文献
13.
R. Navamathavan R. Nirmala Chang Young Kim Cheul-Ro Lee Chi Kyu Choi 《Journal of Physics and Chemistry of Solids》2012,73(5):641-645
Low-dielectric constant SiOC(–H) films were deposited on p-type Si(100) substrates using plasma enhanced chemical vapor deposition (PECVD) at different radio frequency (rf) powers. The structural characteristics of the SiOC(–H) films were characterized using Fourier transform infrared spectroscopy (FTIR) in the absorbance mode. The bonding configurations of the SiOC(–H) films remained unchanged upon annealing, showing their good thermal stability. Electrical characteristics of the SiOC(–H) thin films with Al/SiOC(–H)/p-Si(100)/Al metal-insulator-semiconductor (MIS) structures were analyzed using capacitance–voltage (C–V) and conductance–voltage (G/ω–V) at different frequencies. The conductance and the capacitance measurements were used to extract the interface state density in the MIS structures. From the experimental data and the subsequent quasi-static C–V analysis, the energy distribution of interface state density was obtained. The interface state density of the as-deposited and 400 °C annealed MIS structures increased with increasing rf powers, whereas the fixed charge density decreased with increasing rf powers. The interface state densities and their electrical properties of the SiOC(–H) films strongly affected by the radio frequency power. 相似文献
14.
L. Rebohle J. von Borany H. Fröb W. Skorupa 《Applied physics. B, Lasers and optics》2000,71(2):131-151
The microstructural, optical and electrical properties of Si-, Ge- and Sn-implanted silicon dioxide layers were investigated.
It was found, that these layers exhibit strong photoluminescence (PL) around 2.7 eV (Si) and between 3 and 3.2 eV (Ge, Sn)
at room temperature (RT), which is accompanied by an UV emission around 4.3 eV. This PL is compared with that of Ar-implanted
silicon dioxide and that of Si- and Ge-rich oxide made by rf magnetron sputtering. Based on PL and PL excitation (PLE) spectra
we tentatively interpret the blue–violet PL as due to a T1→S0 transition of the neutral oxygen vacancy typical for Si-rich SiO2 and similar Ge- or Sn-related defects in Ge- and Sn-implanted silicon dioxide. The differences between Si, Ge and Sn will
be explained by means of the heavy atom effect. For Ge-implanted silicon dioxide layers a strong electroluminescence (EL)
well visible with the naked eye and with a power efficiency up to 5×10-4 was achieved. The EL spectrum correlates very well with the PL one. Whereas the EL intensity shows a linear dependence on
the injection current over three orders of magnitude, the shape of the EL spectrum remains unchanged. The I-V dependence exhibiting
the typical behavior of Fowler–Nordheim tunneling shows an increase of the breakdown voltage and the tunnel current in comparison
to the unimplanted material. Finally, the suitability of Ge-implanted silicon dioxide layers for optoelectronic applications
is briefly discussed.
Received: 9 March 2000 / Published online: 30 June 2000 相似文献
15.
A simple evaluation of ion-deposited energy during surface displacement of adatoms has been presented for physical vapor deposition technology using an appropriate interaction model. The rf reactive magnetron sputtering deposition of titanium nitride (TiNx) thin films was taken as evidence supporting the theoretical calculation. The evolution of crystallite morphology dependent on bias (or input power) illustrates that surface and subsurface microstructure of growing films can be optimized by increasing the mobility of adatoms through ion-assistance. 相似文献
16.
M.G. Donato G. Faggio M. Marinelli G. Messina E. Milani A. Paoletti S. Santangelo A. Tucciarone G. Verona Rinati 《The European Physical Journal B - Condensed Matter and Complex Systems》2001,20(1):133-139
High quality synthetic diamonds were grown on single-crystal silicon by microwave plasma enhanced chemical vapour deposition
(CVD). A careful optimisation of both the experimental setup and the growth parameters was necessary before that the achievement
of the best results was made possible. The films were deposited using a CH4-H2 gas mixture at methane concentrations variable in the range 0.6-2.2%, while the substrate temperature was fixed at 750 °C. Raman spectroscopy and photoluminescence (PL) were utilised to monitor the quality of the deposited films and to study
the spatial distribution of defects, respectively. Micro-Raman analysis shows that linewidths of the diamond peak lower than
2.4 cm-1 can be easily measured at the growth surface, indicating that the crystalline quality of individual grains is comparable
to that of the best natural diamonds. The excellent phase purity of the diamond microcrystals at the growth surface is witnessed
by the complete absence of any non-diamond carbon feature and by a very weak luminescence background in the 1.6-2.4 eV spectral
range. A worsening of the quality of the diamond particles is found moving from the growth surface towards the film-substrate
interface. A photoluminescence feature at about 1.68 eV, commonly associated to Si impurities, is distinctly observed as the
exciting laser beam is focused close to the interface. A progressive degradation of the global quality of the films is found
with increasing methane concentration in the gas mixture, as witnessed by an increased PL background in the films grown at
higher methane concentrations.
Received 24 November 2000 相似文献
17.
In this study, SrAl2O4:Eu2+,Dy3+ thin film phosphors were deposited on Si (1 0 0) substrates using the pulsed laser deposition (PLD) technique. The films were deposited at different substrate temperatures in the range of 40-700 °C. The structure, morphology and topography of the films were determined by using X-ray diffraction (XRD), atomic force microscopy (AFM), scanning electron microscopy (SEM) and high resolution transmission electron microscopy (HRTEM). Photoluminescence (PL) data was collected in air at room temperature using a 325 nm He-Cd laser as an excitation source. The PL spectra of all the films were characterized by green phosphorescent photoluminescence at ∼530 nm. This emission was attributed to 4f65d1→4f7 transition of Eu2+. The highest PL intensity was observed from the films deposited at a substrate temperature of 400 °C. The effects of varying substrate temperature on the PL intensity were discussed. 相似文献
18.
P. LahaA.B. Panda S.K. Mahapatra P.K. BarhaiA.K. Das I. Banerjee 《Applied Surface Science》2012,258(7):2275-2282
TiO2/Al2O3/TiO2/Al2O3 multilayer structures were obtained at different oxygen:argon gas ratios of 20:80, 30:70, 50:50 and 60:40 sccm and constant rf power of 200 W using reactive magnetron sputtering. Grain size and elemental distribution in the films were studied from AFM image and XPS spectra respectively. The deposited grain size increased with increasing oxygen:argon gas ratio. The optical band gap, refractive index, extinction coefficient were calculated from UV-vis transmittance and reflectance spectra. It was observed that the value of refractive index, extinction coefficient and band gap increased with increasing oxygen. These variations are due to the defects levels generated by the heterostructure and explained by the PL spectrum. The antireflecting (AR) efficiency of the films was estimated from the reflectance spectra of the films. Broad band antireflecting coating for the visible range was achieved by varying oxygen content in the film. The plasma chemistry controlled the antireflecting property by the interface interdiffusion of atoms during layer transition in multilayer deposition. The in situ investigation of the plasma chemistry was performed using optical emission spectroscopy. The plasma parameters were estimated and correlated with the characteristics of the films. 相似文献
19.
D. Guo K. Cai L.-T. Li Y. Huang Z.-L. Gui 《Applied Physics A: Materials Science & Processing》2002,74(1):69-72
Diamond-like-carbon (DLC) films have been deposited on Si, aluminum and indium tin oxide-coated glass from several organic
solvents with pulse-modulated power. The films are characterized by X-ray photoelectron spectroscopy (XPS) and Raman spectroscopy.
XPS spectra show that the main composition of the films is carbon and Raman spectra show that the films are typical DLC films
and a high potential is preferable in the formation of sp
3-structure carbon. Comparing the results from different solvents and different substrates we deduce that the methyl group
of the solvents has a critical function in forming the DLC films. However, the formation process and the characters of the
films, such as appearance, resistivity and thickness, are mainly determined by the substrate. We may call this deposition
a substrate-controlled reaction.
Received: 31 May 2000 / Accepted: 9 January 2001 / Published online: 3 April 2001 相似文献
20.
Structural and optical properties of zinc nitride films prepared by rf magnetron sputtering 总被引:2,自引:0,他引:2
Tianlin Yang Zhisheng Zhang MaoShui Lv Zhongchen Wu Shenghao Han 《Applied Surface Science》2009,255(6):3544-3547
Zinc nitride films were prepared on quartz substrates by rf magnetron sputtering using pure zinc target in N2-Ar plasma. X-ray diffraction (XRD) analysis indicates that the films just after deposition are polycrystalline with a cubic structure and a preferred orientation of (4 0 0). X-ray photoelectron spectroscopy (XPS) analysis also confirms the formation of N-Zn bonds and the substitution incorporation of oxygen for nitrogen on the surface of the films. The optical band gap is calculated from the transmittance spectra of films just after deposition, and a direct band gap of 1.01 ± 0.02 eV is obtained. Room temperature PL measurement is also performed to investigate the effect of defect on the band gap and quality of the zinc nitride films. 相似文献