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1.
Nitrogen-doped diamond-like carbon (DLC) or amorphous hydrogenated carbon (a-C:H) films were grown by plasma enhanced chemical
vapor deposition using methane and nitrogen gases as precursors. The effects of nitrogen trifluoride (NF3) on these nitrogen-doped DLC films were also investigated. The deposition rate decreases sharply with the addition of nitrogen
in the absence of NFF3 due to dilution, while it increases in the presence of NFF3 due, presumably, to the reduction of activated hydrogen species by the fluorine radical (F϶. X-ray photoelectron spectra
reveal a nitrogen concentration in the range of 9.3 to 13.8% in these DLC films with a C Is electron binding energy of 287-288
eV, indicating the diamond-like structure. Infrared spectra of DLC films indicate the presence of amino groups (N-H) and nitrile
and/or isonitrile (C= N) groups giving strong evidence of sp carbon. Diamond like carbon films deposited in CHF4 +NF4 (with and without NFF3) have a lower refractive index, a lower bulk resistivity, and a lower optical bandgap than films deposited using CHF4 due to a lower hydrogen content in the films. Moreover, the bulk resistivity of these films decreases by over four orders
of magnitude and the optical bandgap decreases from 2.65 eV to about 0.75 eV following annealing at a temperature of 500°C. 相似文献
2.
Ming-Rong Shen Hao Wang Zhao-Yuan Ning Chao Ye Zhao-Qiang Gan Zhao-Xing Ren 《Journal of Electronic Materials》1997,26(8):910-914
Semiconducting diamond-like carbon (DLC) films were deposited on n-type Si substrates by the electrodeposition method, and
diamond films were formed on the carbon film and/or a Si substrate directly by the hot-filament chemical vapor deposition
method. Rectifying heterostructures of Al/DLC/Si/Al, Al/diamond/Si/ Al, and Al/diamond/DLC/Si/Al were fabricated. The Al/DLC/Si/Al
structure has a bulk resistivity of 6 × 105 Ω-cm and a rectification ratio close to two orders of magnitude. Experimental results demonstrate that the Al/diamond/DLC/Si/Al
bilayer structure can significantly reduce the leakage current to about 10-10 A and increase the rectification ratio by 3-5 orders of magnitude at 5 V, compared with that of the other two structures.
Possible reasons are given for the changes of the rectifying characteristic. 相似文献
3.
《Microelectronics Journal》2003,34(5-8):627-629
This work was based on the studies of the influence of the plasma process on the characteristics of diamond-like carbon (DLC) films deposited by high density plasma chemical vapor deposition (HDP-CVD). DLC is a material that shows several good characteristics like high electrical resistivity, lower dielectric constant, high breakdown field, lower stress, high density, and hardness and chemical inertness. This material is important actually in mechanic, optic, and chemistry and mainly in microelectronic areas. For microelectronic process the best results were obtained by plasma of pure methane: low dielectric constant (1.7) and high resistivity 5×1013 Ω cm. 相似文献
4.
E. Broitman N. Hellgren J. Neidhardt I. Brunell L. Hultman 《Journal of Electronic Materials》2002,31(9):L11-L15
The influence of hydrogen content and ambient humidity on the electrical properties of carbon nitride (CNx) films deposited by reactive magnetron sputtering from a graphite target in Ar discharges mixed with N2 and H2 at a substrate temperature of 350°C have been investigated. Carbon films deposited in pure Ar exhibit a dark resistivity
at room temperature of ∼4 × 10−2 Ωcm, while the resistivity is one order of magnitude lower for CN0.25 films deposited in pure N2, due to their denser morphology. The increasing H2 fraction in the discharge gas leads to an increased resistivity for all gas mixtures. This is most pronounced for the nitrogen-free
films deposited in an Ar/H2 mixture, where the resistivity increases by over four orders of magnitude. This can be related to a decreased electron mobility
as H inhibits the formation of double bonds. After exposure to air, the resistivity increases with time through two different
diffusion regimes. The measured electrical properties of the films are related to the apparent film microstructure, bonding
nature, and ambient humidity. 相似文献
5.
The deposition of diamond-like carbon (DLC) films from a mixture of hydrogen and methane using the electron resonance chemical
vapor deposition (ECR-CVD) method with radio-frequency (rf) bias is reported. The structural characteristics of the DLC films
were characterized using Raman spectroscopy. The effects of the self-generated dc bias resulting from the rf power on the
optical gap, Raman spectra, infrared (IR) absorption, and film hardness in depositions carried out at 7 and 15 mTorr process
pressures were investigated. Under conditions of 100 W microwave power and for dc bias variation ranging from −10 to −200
V, there is evidence from Raman scattering analysis to show an increase in the DLC-like characteristic in films deposited
at low dc bias at both process pressures. The variation of the D and G line peak position and intergrated intensity ratio
(ID/IG) in the Raman spectra correlates well with the film hardness profile. There does not seem to be a relationship between the
variation of the C-H absorption peak intensity in the IR spectra (bonded hydrogen content) and the optical gap, although films
with the highest optical gap tend to show a relatively higher C-H absorption peak intensity in the IR spectra. Films deposited
at high dc bias showed a reduction in the C-H infrared absorption, suggesting a reduction in the bonded hydrogen content. 相似文献
6.
TiN was grown by atomic layer deposition (ALD) from tetrakis(dimethylamino)titanium (TDMAT). Both thermal and plasma enhanced processes were studied, with N2 and NH3 as reactive gases. Using an optimized thermal ammonia based process, a growth rate of 0.06 nm/cycle and a resistivity of 53 × 103 μΩ cm were achieved. With an optimized plasma enhanced NH3 process, a growth rate of 0.08 nm/cycle and a resistivity of 180 μΩ cm could be obtained. X-ray photo electron spectroscopy (XPS) showed that the difference in resistivity correlates with the purity of the deposited films. The high resistivity of thermal ALD films is caused by oxygen (37%) and carbon (9%) contamination. For the film deposited with optimized plasma conditions, impurity levels below 6% could be achieved. The copper diffusion barrier properties of the TiN films were determined by in-situ X-ray diffraction (XRD) and were found to be as good as or better than those of films deposited with physical vapor deposition (PVD). 相似文献
7.
Kenji Orita Masao Kawaguchi Yasutoshi Kawaguchi Shinichi Takigawa Daisuke Ueda 《Journal of Electronic Materials》2009,38(4):538-544
High concentration (more than 1 × 1018 cm−3) of hydrogen atoms remaining in Mg-doped GaN epitaxial layers grown by metalorganic chemical vapor deposition even after
conventional annealing in N2 ambient could induce degradation in GaN-based devices containing Mg-doped layers. In this study, by annealing Mg-doped nitrides
in NF3 ambient, we successfully reduced residual hydrogen below mid-1017 cm−3, which is much smaller than by N2 annealing. NF3 annealing enhances outdiffusion of hydrogen from the bulk, which is possibly because the nitrogen and fluorine radicals decomposed
from NF3 accelerate desorption of hydrogen adatoms from the surface. The proposed method for Mg activation would improve the reliability
of GaN-based light-emitting diodes and laser diodes. 相似文献
8.
We have investigated the deposition of titanium nitride (TiN) and diamond-like carbon (DLC ) films on polymethylmethacrylate (PMMA) substrates using pulsed laser deposition (PLD) technique. The TiN and diamond-like films were deposited by laser ablation (KrF excimer laser λ = 248 nm, pulse duration τ~25 × 10?9 s, energy density ~2?15J/cm2) of TiN and graphite targets, respectively, at room temperature. These films were characterized by transmission electron microscopy, scanning electron microscopy, x-ray diffraction, Auger electron spectroscopy, UV-visible absorption spectroscopy, and Raman spectroscopy. The TiN films were smooth and found to be polycrystalline with average grain size of 120Å. The diamond-like carbon films were amorphous with a characteristic Raman peak at 1550 cm?1. The TiN films are highly adherent to the polymer substrates as compare to DLC films. The adhesion strength of DLC films on polymers was increased by interposing thin TiN layer (200Å) on polymers byin-situ pulsed laser deposition. The DLC films were found to be amorphous with good adhesion to TiN/PMMA substrates. 相似文献
9.
Diamond-like carbon (DLC) films were deposited on the organic photoconductor (OPC) drum of the laser printer using the dc-remote
plasma enhancement chemical vapor deposition (RPECVD) method. Only methane (CH4) was used as a source gas for DLC coating. The transmittance of the DLC coatings is over 90% and the hardness of the DLC
film (130 nm thick) coated OPC drum is higher than 1,000 Hv. Effects of dc-power on the physical properties of the DLC film and the electrophotographic properties of the DLC coated
OPC drum were investigated. The hardness and the deposition rate of the DLC film deposited on the OPC drum increased but the
transmittance and the surface roughness nearly did not change with increasing the dc power of the dc-RPECVD. The residual
potential, the acceptance voltage, and the dark decay rate significantly increase but the photodischarge rate decreases with
increasing the dc power of the RPECVD. The optimum dc power is 8.6 kW (950 V, 6A). The friction coefficient of the OPC drum
is also lowered by DLC coating. In addition, it was found that the DLC deposition rate could be doubled by imposing magnetic
fields around the cathode. 相似文献
10.
Ravindra V. Tanikella Sairam Agraharam Sue A. Bidstrup Allen Dennis W. Hess Paul A. Kohl 《Journal of Electronic Materials》2002,31(10):1096-1103
The moisture absorption and diffusion characteristics of fluorocarbon films deposited from pentafluoroethane (PFE) and octafluorocyclobutane
C4F8 plasmas are presented. The moisture absorption studies were carried out using a quartz crystal microbalance in a controlled
environment. X-ray photoelectron spectroscopy and Fourier transform infrared (IR) spectroscopy were used to monitor the changes
in bulk and surface chemical structure and composition of the deposited films. The equilibrium moisture uptake at relative
humidity >90% was lower than 0.13 wt.% for films deposited from PFE or C4F8 monomers. Humidity cycling measurements showed no moisture chemisorption in the deposited films. Attenuated total reflectance
infrared spectroscopy (ATR-IR) spectra of the deposited films indicated negligible change in the bulk composition of the deposited
films. The estimated diffusivities of water in the deposited fluorocarbon films were of the order of 10−10 cm2/sec, and films deposited from C4F8 monomer showed higher diffusivity as compared to films deposited from PFE monomer. The equilibrium moisture uptake is affected
by the presence of polar groups, the F/C ratio, and the O/C ratio. The relatively high diffusivity of water in the fluorocarbon
films is attributed to the lack of polar groups in the deposited films. Adsorption onto the surface followed by diffusion
into the bulk is proposed as the mechanism for moisture absorption in the fluorocarbon films. Finally, the moisture uptake
of the fluorocarbon and hydrofluorocarbon films is compared to that of a conventionally used microelectronic polymer, polyimide
(PI 2611), in order to evaluate the effect of polar groups and fluorine content on diffusion and equilibrium moisture uptake. 相似文献
11.
Plasma-deposited silicon nitride films were produced from SiH4-N2 gas mixture. Their composition, chemical bonds, and electrical properties were investigated by varying the deposition conditions.
The silicon nitride films from SiH4-N2 gas mixture exhibit (i) less hydrogen, (ii) higher thermal endurance, (iii) higher density, and (iv) smaller etching rate
than those of the films deposited from SiH4, and NH3 gas mixture. These results can be partly attributed to lower hydrogen concentration. As the Si/N ratio approaches the stoichiometric
value, 0.75, the resistivity and the breakdown strength are increased. They are 1015Ωcm and 9MV/cm, respectively, at Si/N≃0.85. Interface state density between silicon and silicon nitride layers is as low as
1& #x223C; 5xl011cm−2 eV−1.
On leave from The Northwest Telecommunication Engineering Institute, Xi’an, The People’s Republic of China. 相似文献
12.
ZnO/diamond-like carbon(DLC)thin films are deposited by pulsed laser deposition(PLD),and the room-temperature photoluminescence(PL)is investigated.Using a fluorescence spectrophotometer,we obtain the PL spectra of DLC/Si and ZnO/Si thin films deposited at different substrate temperatures.The ZnO/DLC thin films show a broadband emission almost containing the entire visible spectrum.The Gaussian fitting curves of PL spectra reveal that the visible emission of ZnO/DLC thin films consists of three peaks centered at 381 nm,526 nm and 682 nm,which are attributed to the radiative recombination of ZnO and DLC,respectively.The Commission International de l,Eclairage(CIE)1931(x,y)chromaticity space of ZnO/DLC thin films indicates that the visible PL spectrum is very close to the standard white-light region. 相似文献
13.
Samerkhae Jongthammanurak Maetapa Witana Tinnaphob Cheawkul Chanchana Thanachayanont 《Materials Science in Semiconductor Processing》2013,16(3):625-632
ZnO films were deposited on glass substrates in the temperature range of 350–470 °C under an atmosphere of compressed air or nitrogen (N2) by using ultrasonic spray pyrolysis technique. Structural, electrical and optical properties of the ZnO films were investigated using X-ray diffraction (XRD), scanning electron microscopy (SEM), electrical two-probe and optical transmittance measurements. The ZnO films deposited in the range of 350–430 °C were polycrystalline with the wurtzite hexagonal structure having preferred orientation depending on the substrate temperature. The ZnO films deposited below 400 °C had a preferred (100) orientation while those deposited above 400 °C mostly had a preferred (002) orientation. The resistivity values of ZnO films depended on the types of carrier gas. The ZnO thin films deposited under N2 atmosphere in the range of 370–410 °C showed dense surface morphologies and resistivity values of 0.6–1.1 Ω-cm, a few orders of magnitude lower than those deposited under compressed air. Hydrogen substition in ZnO possibly contributed to decreasing resistivity in ZnO thin films deposited under N2 gas. The Hall measurements showed that the behavior of ZnO films deposited at 410 °C under the N2 atmosphere was n-type with a carrier density of 8.9–9.2×1016 cm-3 and mobility of ~70 cm2/Vs. ZnO thin films showed transmission values at 550 nm wavelength in a range of 70–80%. The values of band gaps extrapolated from the transmission results showed bandgap shrinkage in an order of milli electron volts in ZnO films deposited under N2 compared to those deposited under compressed air. The calculation showed that the bandgap reduction was possibly a result of carrier–carrier interactions. 相似文献
14.
M. I. Medina-Montes S. H. Lee M. Pérez L. A. Baldenegro-Pérez M. A. Quevedo-López B. Gnade R. Ramírez-Bon 《Journal of Electronic Materials》2011,40(6):1461-1469
In this work we present the electrical characterization of ZnO-based thin-film transistors fabricated at room temperature.
The ZnO films were deposited by radiofrequency magnetron sputtering at variable argon pressure (3 mTorr to 10 mTorr) at room
temperature. The sputtered ZnO films were polycrystalline with hexagonal structure and electrical resistivity ranging from
101 Ω cm to 108 Ω cm for films deposited from 3 mTorr to 10 mTorr. The trend in the electrical behavior of the devices was found to be due
to the variation of the electron concentration of the ZnO films. The devices with better performance showed a field-effect
mobility of 2.9 cm2/Vs, threshold voltage of 20 V, I
on/I
off ≈ 106, and electrical resistivity of ~108 Ω cm. In addition, linear behavior of I
on/I
off with deposition pressure was observed. The lowest I
on/I
off ratio (~2) was calculated for devices with ZnO layers deposited at 3 mTorr, and the highest ratio (~106) for devices processed at 10 mTorr. Hall-effect measurements were performed on ZnO films showing the lowest resistivity.
The layer grown at 3 mTorr showed a Hall mobility of μ
H = 8.9 cm2/Vs and carrier concentration of n = 4.2 × 1016 cm−3 with resistivity of ρ = 31.8 Ω cm. For films deposited at 5 mTorr, the Hall mobility, carrier concentration, and resistivity were μ
H = 7.9 cm2/Vs, n = 3.4 × 1016 cm−3, and ρ = 38.4 Ω cm, respectively. Films deposited at 8 mTorr and 10 mTorr could not be measured due to their high resistance. 相似文献
15.
Thin films of InAs have been deposited on mica substrates through a vacuum evaporation technique by means of controlling the
substrate and source temperatures. The films with large crystal grain were found to have the best electrical properties. The
maximum electron mobility of 12, 400 cm2/V·sec at room temperature was obtained in an undoped film of 3 Μm thickness at a donor concentration of 3.5 × 1016 cm−3. The temperature dependence of both electron mobility and resistivity of these films was slightly lower than those reported
for bulk crystal type InAs. 相似文献
16.
A. I. Abdulagatov Sh. M. Ramazanov R. S. Dallaev E. K. Murliev D. K. Palchaev M. Kh. Rabadanov I. M. Abdulagatov 《Russian Microelectronics》2018,47(2):118-130
Aluminum nitride (AlN x ) films were obtained by atomic layer deposition (ALD) using tris(diethylamido) aluminum(III) (TDEAA) and hydrazine (N2H4) or ammonia (NH3). The quartz crystal microbalance (QCM) data showed that the surface reactions of TDEAA and N2H4 (or NH3) at temperatures from 150 to 225°C were self-limiting. The rates of deposition of the nitride film at 200°C for systems with N2H4 and NH3 coincided: ~1.1 Å/cycle. The ALD AlN films obtained at 200°C using hydrazine had higher density (2.36 g/cm3, 72.4% of bulk density) than those obtained with ammonia (2.22 g/cm3, 68%). The elemental analysis of the film deposited using TDEAA/N2H4 at 200°C showed the presence of carbon (~1.4 at %), oxygen (~3.2 at %), and hydrogen (22.6 at %) impurities. The N/Al atomic concentration ratio was ~1.3. The residual impurity content in the case of N2H4 was lower than for NH3. In general, it was confirmed that hydrazine has a more preferable surface thermochemistry than ammonia. 相似文献
17.
The deposition of a protective film to increase the hardness of an organic photoconductor (OPC) surface is an effective method
of lengthening the lifetime of the OPC. In this work, diamond-like carbon (DLC) protective films were deposited onto OPC samples
by the electron cyclotron resonance (ECR)-microwave plasma chemical vapor deposition (MPCVD) method with low substrate temperature.
The DLC films were deposited with optimized deposition conditions and exhibited high transmissivity and high electrical resistivity.
The films caused a remarkable increase in the hardness of the OPC surface, by a factor of 2.5∼5.4. The acceptance voltage,
dark decay rate, photodischarge rate, and contrast potential of the OPC protected by DLC film were improved. These results
show DLC is a suitable protective film for OPC. 相似文献
18.
I. S. Virt T. P. Shkumbatyuk I. V. Kurilo I. O. Rudyi T. Ye. Lopatinskyi L. F. Linnik V. V. Tetyorkin A. G. Phedorov 《Semiconductors》2010,44(4):544-549
Bi2Te3 and Sb2Te3 films were obtained by pulsed laser ablation. The films were deposited in vacuum (1 × 10−5 Torr) on single crystal substrates of Al2O3 (0001), BaF2 (111), and fresh cleavages of KCl or NaCl (001) heated to 453–523 K. The films were 10–1500 nm thick. The structures of the
bulk material of targets and films were studied by X-ray diffractometry and transmission high-energy electron diffraction,
respectively. Electrical properties of the films were measured in the temperature range of 77–300 K. It is shown that the
films possess semiconductor properties. Several activation portions are observed in the temperature dependences of resistivity;
the energies of activation portions depend on the film thickness and crystallite size. 相似文献
19.
Aluminum oxide films (amorphous and γ-Al2O3) have been deposited by the oxidation of trimethy1aluminum. Process parameters have been evaluated and optimized to obtain
reasonable growth rates and film properties for deposition temperatures between 300 and 400° C. Values of the dielectric constant
(7.5 – 7.8), the dielectric strength (7.5 – 7.9 × 106 V/cm), the index of refraction (1.54 – 1.67), and the resistivity (> 10 ohm-cm) compare favorably with Al2O3, films grown with other processes at higher deposition temperatures. Film analysis by secondary ion mass spectrometry identified
a distribution of carbon and sodium impurities. 相似文献
20.
C-axis oriented ZnO films are deposited on polished diamond substrates in various O2/(O2+Ar) ratios using the radio frequency (RF) magnetron sputtering technique and are subsequently annealed in oxygen ambience
under the same conditions. Structural, morphologic and electrical properties of ZnO films are characterized by X-ray diffraction
(XRD), high-resistance instrument, energy dispersive X-ray spectroscopy (EDS) and scanning electronic microscopy (SEM). As
the O2/(O2+Ar) ratio increasing from 1/12 to 5/12, the crystallinity of the as grown ZnO films becomes better and the electrical resistivity
increases slowly. After annealing, the ZnO films deposited in O2/(O2+Ar) =1/12 and 3/12 are improved greatly in crystallinity, and their electrical resistivity is enhanced by two orders of magnitude,
while those deposited in O2/(O2+Ar) =5/12 are scarcely changed in crystallinity, and their resistivity is only increased by one order. In addition, the ZnO
films deposited in O2/(O2+Ar) =3/12 and annealed in oxygen are with the best crystal quality and the highest resistivity. 相似文献