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1.
Nanocrystalline diamond (NCD) films were produced by microwave plasma-enhanced chemical vapor deposition (MPECVD) using gas
mixtures of Ar, H2, and CH4. The structural properties, electron emission, and electric discharge behaviors of the NCD films varied with H2 flow rates during MPECVD. The turn-on field for electron emission at a pressure of 2.66 × 10−4 Pa increased from 4.2 V μm−1 for the NCD films that were deposited using a H2 flow rate of 10 cm3 min−1 to 7 V μm−1 for films deposited at a H2 flow rate of 20 cm3 min−1. The NCD film with a low turn-on field also induced low breakdown voltages in N2. The grain size and roughness of the NCD films may influence both the electron emission and the electric discharge behaviors
of the NCD cathodes. 相似文献
2.
Nicholas Licausi Wen Yuan Fu Tang Thomas Parker Huafang Li Gwo-Ching Wang Toh-Ming Lu Ishwara Bhat 《Journal of Electronic Materials》2009,38(8):1600-1604
Continuous biaxially textured CdTe films were grown on biaxial CaF2 buffer layers. The CaF2 nanorods were grown by oblique angle vapor deposition and possessed a {111} 〈121〉 biaxial texture. The CdTe film was deposited
by metal organic chemical vapor deposition (MOCVD). Film morphology and the CdTe/CaF2 interface were studied by scanning electron microscopy and transmission electron microscopy. Characterization showed that
small CdTe grains formed initially from the CaF2 surfaces. These small grains then merged into large columnar grains during growth. Analysis revealed that the crystalline
orientation of the CdTe film followed the biaxial texture of the CaF2 nanorods. 相似文献
3.
N. H. Karam R. Sudharsanan T. Parodos M. A. Dodd 《Journal of Electronic Materials》1996,25(8):1209-1214
Epitaxial In1-xTlxSb films with compositions up to x = 0.1 have been demonstrated using the metalorganic chemical vapor deposition technique
on InSb and GaAs substrates. A specially designed high-temperature source delivery system was used for the low vapor pressure
cyclopentadienylthallium source. Tl-compositions in the deposited films were measured by Rutherford backscattering spectroscopy
which confirmed the incorporation of up to 10% Tl. Room temperature infrared transmission spectra of InTISb exhibited considerable
absorption beyond 7 μm. Photoconductive detectors were fabricated in InTISb films grown on semi-insulating GaAs. Spectral
response measurements showed substantial photoresponse at 8.5 to 14 μm. In spite of the large lattice-mismatch (≈14%) between
InTISb and GaAs, photoconductive detectors exhibited black-body detectivities (D*
bb) of 5.0 × 108 cm-Hz1/2W−1 at 40K. 相似文献
4.
A growth parameter study was made to determine the proper of a SiGe superlattice-type configuration grown on Si substrates
by chemical vapor deposition (CVD). The study included such variables as growth temperature, layer composition, layer thickness,
total film thickness, doping concentrations, and film orientation. Si and SiGe layers were grown using SiH4 as the Si source and GeH4 as the Ge source. When intentional doping was desired, diluted diborane for p-type films and phosphine for n-type films were
used. The study led to films grown at ∼1000°C with mobilities from ∼20 to 40 percent higher than that of epitaxial Si layers
and ∼100 percent higher than that of epitaxial SiGe layers grown on (100) Si in the same deposition system for net carrier
concentrations of ∼8x1015 cm-3 to ∼2x1017 cm-3. Enhanced mobilities were found in multilayer (100)-oriented Si/Si1-xGex films for layer thicknesses ≥400A, for film thicknesses >2μm, and for layers with x = 0.15. No enhanced mobility was found
for (111)-oriented films and for B-doped multilayered (100)-orlented films.
Supported in part by NASA-Langley Research Center, Hampton, VA, Contract NAS1-16102 (R. Stermer & A. Fripp, Contr. Mon.) 相似文献
5.
Hydrogenated microcrystalline silicon-germanium (μc-SiGe:H) films are fabricated by radio-frequency plasma-en- hanced chemical vapor deposition (RF-PECVD). The optical absorption coefficient and the photosensitivity of the μc-SiGe:H films increase dramatically by increasing the plasma power and deposition pressure simultaneously. Addi- tionally, the microstructural properties of the μc-SiGe:H films are also studied. By combining Raman, Fourier trans- form infrared (FTIR) and X-ray fluoroscopy (XRF) measurements, it is shown that the Ge-bonding configuration and compactability of theμc-SiGe:H thin films play a crucial role in enhancing the optical absorption and optimizing the quality of the films via a significant reduction in the defect density. 相似文献
6.
K. W. Vogt M. Houston M. F. Ceiler C. E. Roberts P. A. Kohl 《Journal of Electronic Materials》1995,24(6):751-755
The dielectric properties of plasma-enhanced chemical vapor deposition (PECVD) SiO2 deposited at 150°C were improved by reaction with anhydrous hydrazine vapor at 150–350°C. The permittivity and loss decreased
~32% and ~86%, respectively, after reaction with hydrazine at 150°C. The decrease in permittivity and loss correlated with
a decrease in the dipole concentration (silanol + water). During exposure to humid conditions, water uptake in the SiO2 films degraded the dielectric properties. A nitrogen anneal at 350°C did not improve the dielectric properties of the PECVD
SiO2. Although water was removed from the films, silanol remained. When the PECVD SiO2 deposited at 150° was reacted with hydrazine vapor at 150°C, both silanol and water were removed from the films. The dielectric
properties and resistance to water absorption improved. 相似文献
7.
分别以Si2 H6和GeH4及SiH4和GeH4两种组合气体为源气体,用甚高频等离子增强化学气相沉积(VHF-PECVD)制备μc-SiGe薄膜.用Raman散射光谱和原子力显微镜(AFM)对薄膜的结构进行研究.结果表明:与SiH4和GeH4制备的薄膜系列相比,Si2H6和GeH4制备的薄膜中Ge的融入速率相对较慢;用... 相似文献
8.
P. Tiwari X. D. Wu S. R. Foltyn I. H. Campbell Q. X. Jia R. E. Muenchausen D. E. Peterson T. E. Mitchell 《Journal of Electronic Materials》1996,25(1):51-55
Highly crystalline SrRuO3 (SRO) and La0.5Sr0.5CoO3 (LSCO) thin films were deposited on (100) Pt/ MgO by pulsed laser deposition. The films were mainly (001) textured normal
to the substrate surface with a high degree of in-plane orientation with respect to the substrate’s major axes. These films
were characterized using x-ray diffraction, Rutherford backscattering, four-point probe resistivity measurement, and transmission
electron microscopy. The room temperature resistivity for LSCO and SRO films on Pt/MgO was found to be ∼35 and ∼40 μΩ-cm,
respectively. An ion beam minimum channeling yield of ∼43% and ∼33% was obtained for LSCO and SRO films, respectively. The
interface between Pt and oxide was found to be smooth and free from any interfacial diffusion. This result showed that high-quality
low resistivity oxide thin films can be deposited on Pt. 相似文献
9.
P. Tiwari Mary Longo G. Matera S. Sharan P. L. Smith J. Narayan 《Journal of Electronic Materials》1991,20(7):775-778
We have investigated the formation of TiSi2 and CoSi2 thin films on Si(100) substrates using laser (wave length 248 nm, pulse duration 40 ns and repetition rate 5 Hz) physical
vapor deposition (LPVD). The films were deposited from solid targets of TiSi2 and CoSi2 in vacuum with the substrate temperature optimized at 600° C. The films were characterized using x-ray diffraction, scanning
electron microscopy (SEM), transmission electron microscopy (TEM) and four point probe ac resistivity. The films were found
to be polycrystalline with a texture. The room temperature resistivity was found to be 16 μΩ-@#@ cm and 23 μΩ-cm for TiSi2 and CoSi2 films, respectively. We optimized the processing parameters so as to get particulate free surface. TEM results show that
the silicide/silicon interface is quite smooth and there is no perceptible interdiffusion across the interface. 相似文献
10.
Dimitrios N. Kouvatsos Apostolos T. Voutsas Miltiadis K. Hatalis 《Journal of Electronic Materials》1999,28(1):19-25
In this work, we have characterized various types of polysilicon films, crystallized upon thermal annealing from films deposited
by low pressure chemical vapor deposition in the amorphous phase and a mixed phase using silane or in the amorphous phase
using disilane. Polysilicon thin film transistors (TFTs) were fabricated, at low processing temperatures, in these three types
of films on high strain point Corning Code 1734 and 1735 glass substrates. Double layer films, with the bottom layer deposited
in a mixed phase and the top in the amorphous phase, allowed TFT fabrication at a drastically reduced thermal budget; optimum
values of thicknesses and deposition rates of the layers are reported for reducing the crystallization time and improving
film quality. Optimum deposition conditions for TFT fabrication were also obtained for films deposited using disilane. The
grain size distribution for all types of films was shown to be wider for a larger grain size. Fabricated TFTs exhibited field
effect electron mobility values in the range of 20 to 50 cm2/V·s, subthreshold swings of about 0.5–1.5 V/dec and threshold voltage values of 2–4 V. 相似文献
11.
X. L. Xu V. Misra M. C. Öztürk J. J. Wortman G. S. Harris D. M. Maher L. Spanos E. A. Irene 《Journal of Electronic Materials》1993,22(11):1345-1351
An oxygen doped microcrystalline silicon (μc-Si) deposition process is developed by mixing small amounts of nitrous oxide
(N2O) with silane (SiH4) in a rapid thermal chemical vapor deposition (RTCVD) reactor. The effects of oxygen doping on the properties of RTCVD μc-Si
films are studied. Experimental results show that the RTCVD process provides high deposition rates for μc-Si and polycrystalline
silicon (polySi) films at elevated deposition temperatures and pressures. The surface roughness of the RTCVD μc-Si films can
be significantly reduced compared to that of conventional LPCVD polySi films. Steep side walls can be realized due to the
small grain size of the μc-Si films. The sheet resistance of BF2 doped μc-Si films is slightly higher than that of BF2 doped polySi films, whereas sheet resistances of P and As doped μc-Si films are much higher than those of the corresponding
P and As doped polySi films. Measurements of the catastrophic breakdown strength of metal-oxide-semiconductor (MOS) capacitors
indicate that the quality of gate electrodes fabricated using μc-Si is improved relative to that of MOS capacitors fabricated
using polySi gate electrodes. 相似文献
12.
Thin-film transistors (TFTs) fabricated in polysilicon films deposited by plasma enhanced chemical vapor deposition (PECVD)
were characterized. The transistors were fabricated using a low temperature process (i.e., <- 700° C). The characteristics of the devices were found to improve as the deposition temperature of the polysilicon film
increased. The best characteristics (μ
FE of 15 cm2/V
s andV
TH of 2.2V) were measured in the devices fabricated in the film deposited at 700° C. The devices fabricated in the PECVD polysilicon
films were compared to those fabricated in polysilicon films deposited by thermal CVD in the same reactor in order to decouple
the effect of the plasma. A coplanar electrode structure TFT with adequate characteristics (μ
FE of 8 cm2/V
s) was also demonstrated in the PECVD polysilicon films. 相似文献
13.
La-modified lead titanate (PLT) thin films were prepared by hot-wall type low pressure-metalorganic chemical vapor deposition
method. Pb(dpm)2, La(dpm)3, and titanium tetraisopropoxide were used as source materials. The films were deposited at 500°C under the low pressure of
1000 mTorr and then annealed at 650°C for 10 min in oxygen ambient. Sputter-deposited platinum electrodes and 180 nm thick
PLT thin films were employed to form MIM capacitors with the best combination of high charge storage density (26.7 μC/cm2 at 3V) and low leakage current density (1.5 × 10-7 A/cm2 at 3V). The measured dielectric constant and dielectric loss were 1000∼1200 and 0.06∼0.07 at zero bias and 100 kHz, respectively. 相似文献
14.
D. Landheer Z. -H. Lu J. -M. Baribeau L. J. Huang W. M. Lau 《Journal of Electronic Materials》1994,23(9):943-952
GaAs and InP surfaces have been prepared by gas-phase and liquid-phase polysulfide passivation techniques followed by the
deposition of Si interface control layers (ICLs) by e-beam evaporation. For GaAs surfaces, the performance of an ICL consisting
of 1.5 nm Si on top of 0.5 nm of Ge has also been evaluated. Metal-insulator-semiconductor diodes with aluminum top electrodes
were fabricated on these surfaces using silicon nitride deposited by a remote plasma-enhanced chemical vapor technique or
silicon dioxide deposited by a conventional direct plasma-enhanced chemical vapor deposition technique. The quality of the
interfaces was analyzed by capacitance-voltage (C-V) measurements and the interface state densities Dit were deduced from the C-V data using the high-low method. Values as low as 1.5 × 1012 eV−1cm−2 were obtained for polysulfide-passivated GaAs surfaces with a Ge-Si or Si ICL, the lowest ever demonstrated using the high-low
method for an ex-situ technique not involving GaAs epitaxy. For InP, the Si ICL does not reduce Dit below that of 2 × 1012 eV−1
cm
−2 that was obtained for the polysulfide passivated surface. The Si ICL produces an interface that degrades more slowly on exposure
to air for both GaAs and InP. 相似文献
15.
Alain E. Kaloyeros Aiguo Feng Jonathan Garhart Kenneth C. Brooks Sumanta K. Ghosh Arjun N. Saxena Fred Luehrs 《Journal of Electronic Materials》1990,19(3):271-276
Copper films for potential use in multilevel metallization in ULSIC’s were produced by low temperature (250–350° C) metal-organic
chemical vapor deposition (LTMOCVD) in atmospheres of pure H2 or mixture Ar/H2 from the β-diketonate precursor bis(1,1,1,5,5,5-hexafluoroacetylacetonato) copper(ll), Cu(hfa)2. The films were analyzed by x-ray diffraction (XRD), Rutherford backscattering (RBS), Auger electron spectroscopy (AES),
scanning electron microscopy (SEM), and energy-dispersive x-ray spectroscopy (EDXS). The results of these studies showed that
the films were uniform, continuous, adherent and highly pure—oxygen and carbon contents were below the detection limits of
AES. Four point resistivity measurements showed that the copper films had very low resistivity, as low as 1.9 μΩcm for the
films deposited in pure hydrogen atmosphere. Our preliminary results seem to indicate that LTMOCVD is a very attractive technique
for copper multilevel metallizations. 相似文献
16.
Copper chemical vapor deposition from Cu(hexafluoroacetylacetonate)trimethylvinylsilane (Cu(hfac)TMVS) was studied using a
low pressure chemical vapor deposition system of a cold wall vertical reactor. The Cu films deposited using H2 as a carrier gas revealed no impurities in the films within the detection limits of Auger electron spectroscopy and x-ray
photoelectron spectroscopy. Using hydrogen as a carrier gas, the hydrogen not only acts as a reducing agent, but also reacts
with the residual fragment of precursor. As a result, using H2 as a carrier gas for Cu(hfac)TMVS resulted in Cu films of lower resistivity, denser microstructure and faster deposition
rate than using Ar or N2 as the carrier gas. Moreover, we found that N2 plasma treatment on the substrate surface prior to Cu deposition increased the deposition rate of Cu films. 相似文献
17.
Hydrogenated amorphous silicon-carbon (a-Si:C:H) and hydrogenated silicon-nitrogen (a-Si:N:H) antireflective films were deposited
by plasma-enhanced chemical vapor deposition (PECVD) at 13.56 MHz in SiH4 + CH4 and SiH4 + NH3 gaseous mixtures of various compositions. The silicon and glass samples were investigated by optical spectroscopy, Fourier-transform
infrared spectroscopy (FTIR), and scanning electron microscopy (SEM). A correlation between film properties and process parameters
was found. The refractive index decreased and the energy gap increased with an increase of carbon and nitrogen in the films.
For some process parameters, it was possible to obtain smooth, hydrogen rich, and homogeneous films of low reflectivity. The
silicon solar cells with antireflective coatings revealed an increase in efficiency. 相似文献
18.
Jie Sun Devin A. Mourey Dalong Zhao Thomas N. Jackson 《Journal of Electronic Materials》2008,37(5):755-759
We report undoped ZnO films deposited at low temperature (200°C) using plasma-enhanced chemical vapor deposition (PECVD).
ZnO thin-film transistors (TFTs) fabricated using ZnO and Al2O3 deposited in situ by PECVD with moderate gate leakage show a field-effect mobility of 10 cm2/V s, threshold voltage of 7.5 V, subthreshold slope <1 V/dec, and current on/off ratios >104. Inverter circuits fabricated using these ZnO TFTs show peak gain magnitude (dV
out/dV
in) ~5. These devices appear to be strongly limited by interface states and reducing the gate leakage results in TFTs with lower
mobility. For example, ZnO TFTs fabricated with low-leakage Al2O3 have mobility near 0.05 cm2/V s, and five-stage ring-oscillator integrated circuits fabricated using these TFTs have a 1.2 kHz oscillation frequency
at 60 V, likely limited by interface states. 相似文献
19.
The properties of low-k SiCOH film deposited by plasma-enhanced chemical vapor deposition using trimethylsilane are reported here. The deposition process was performed at different temperatures from 200 to 400 °C. The influence of deposition temperature on the films were characterized using Fourier transform infrared spectroscopy (FTIR) to understand its impact on the studied properties. The films were annealed at ∼450 °C in an inert ambient after deposition in all the cases. The deposition rate decreases with increase in deposition temperature. The refractive index of the films increases as a function of deposition temperature. From FTIR spectra, OH-related bonds were not detected in films even when deposited at 200 °C. The Si-CH3 bonds were detected in all the films and decreased monotonically from 200 to 400 °C. All deposition conditions studied resulted in films with dielectric constant less than 3, the lowest being ∼2.7 when deposited at 200 °C. All films exhibited good thermal stability. 相似文献
20.
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