Parameters determining crystallinity in β-SiC thin films prepared by catalytic chemical vapor deposition

Zhao, Quanzhong; Li, J.C.; Zhou, Hai; Wang, H.; Wang, B.; Yan, Hui

doi:10.1016/j.jcrysgro.2003.08.026

Cited by 25 publications

(13 citation statements)

References 13 publications

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“…This result in increasing the number of molecules that collide with each other and precursor will decompose completely. This indicates the possibility of increased Si-C bonding with increase in deposition pressure [17]. The FWHM is found to decrease with increase in deposition pressure indicative of the enhancement in crystallinity and this result is in agreement with the XRD result.…”

Section: Structural Propertiessupporting

confidence: 86%

Growth and effect of deposition pressure on microstructure and electrical properties of 3C-SiC thin films deposited using methyltrichlorosilane single precursor

Latha¹,

Udayakumar²,

Prasad³

2013

Int. J. Thin Film Sci. Tec.

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This paper presents effect of deposition pressure on the microstructure and electrical properties of 3C-SiC (111) thin films. These films are deposited at a temperature of 1040 • C and pressures of 1.5, 1.8, 2.5 and 2.7 mbar, on thermally oxidized Si (100) substrates from a mixture of methyltrichlorosilane and hydrogen gas using a vertical hot wall, low pressure chemical vapour deposition (LPCVD) reactor. The above properties are investigated for all films using X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), Scanning electron microscopy (SEM) and four probe technique. An FTIR spectrum shows the formation of Si-C bonding of deposited films. The SEM and XRD investigations show improvement in the grain size and crystallanity, decrease in strain and dislocations of the films with increase in the deposition pressure from 1.5 to 2.5 mbar. AFM investigations show decrease in roughness of the films with increase in the deposition pressure from 1.55 to 2.5 mbar. The sheet resistance of 3C-SiC thin films is found to decrease with increase in temperature in the range of 35 to 550 • C. Comparing all the films, 3C-SiC thin films deposited at a pressure of 2.5 mbar and temperature of 1040 • C exhibited improved structural and electrical properties.

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Section: Structural Propertiessupporting

confidence: 86%

Growth and effect of deposition pressure on microstructure and electrical properties of 3C-SiC thin films deposited using methyltrichlorosilane single precursor

Latha¹,

Udayakumar²,

Prasad³

2013

Int. J. Thin Film Sci. Tec.

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“…These adsorbed hydrogen atoms undergo rearrangement reactions at the surface, leading to the formation of pc-Si films. The same conclusion was reached by Zhao et al, 12 who showed that the crystallinity of the deposited silicon carbide (SiC) thin films was improved upon the usage of a higher total gas pressure with a mixture composed of SiH 4 , CH 4 , and H 2 . More recently, Tehrani et al 13 studied the effect of pressure on the composition and optical properties of SiC films deposited by HWCVD using a mixture of SiH 4 and CH 4 .…”

Section: Introductionsupporting

confidence: 68%

“…Summary of the intensity ratios of each of the peaks at m/z 73, 116, and 118 to that of the parent peak at m/z 60 when using 0. 12 Note: The lower value in the range is calculated from the data collected at the beginning of the run and the higher value in the range is calculated from the data collected in the last stage of the experiment. on.…”

Section: Intensity (Au)mentioning

confidence: 99%

Effect of pressure on the gas-phase chemistry when using monomethylsilane and dimethylsilane in hot-wire chemical vapor deposition

ToukabriRim

ShiYujun

2015

Can. J. Chem.

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The effect of source gas pressure on the gas-phase reaction chemistry of dimethylsilane (DMS) and monomethylsilane (MMS) in the hot-wire chemical vapor deposition process has been studied by examining the secondary gas-phase reaction products in a reactor using a soft laser ionization source coupled with mass spectrometry. For DMS, the increase in sample pressure has resulted in the formation of small hydrocarbons, including ethene, acetylene, propene, and propyne. This leads to a switch from silylene dominant chemistry to a free radical dominant one with the pressure increase at low filament temperatures of 1200 and 1300°C. At the lower pressure of 0.12 Torr, the formation of 1,1,2,2-tetramethyldisilane by dimethylsilylene insertion reaction into the Si-H bond in DMS is favored over trimethylsilane produced from a free radical recombination reaction for a short reaction time. However, when the pressure is increased by 10 times, the gas-phase chemistry becomes dominated by the formation of trimethylsilane. We have demonstrated that trapping of the corresponding active intermediates by the small hydrocarbons produced in situ is responsible for the observed switch. In the study with MMS, the gas-phase chemistry is dominated by the formation of 1,2-dimethyldisilane and 1,3-disilacyclobutane at both pressures of 0.48 and 1.2 Torr. Unlike DMS, the gas-phase reaction chemistry with MMS does not involve free radicals, which are the precursors to produce small hydrocarbons. The absence of small hydrocarbons formed in situ with MMS explains the preservation in chemistry upon the increase in pressure when MMS is used as a source gas.Résumé : On a étudié dans un réacteur l'effet de la pression du gaz source sur la réaction en phase gazeuse du diméthylsilane (DMS) et du monométhylsilane (MMS) par un procédé de dépôt chimique en phase vapeur à fil chaud, en étudiant les produits secondaires dans la phase gazeuse au moyen d'un laser de faible puissance utilisé comme source d'ionisation et couplé avec un spectromètre de masse. Dans le cas du DMS, l'augmentation de la pression de l'échantillon a entraîné la formation d'hydrocarbures légers, notamment l'éthène, l'acétylène, le propène et le propyne. On en déduit que l'environnement chimique où la formation du silylène prédomine passe à un environnement chimique où la formation de radicaux libres prédomine dans lequel une augmentation de la pression s'est produite à de basses températures du filament (1200 et 1300°C). À la pression la plus faible (0,12 Torr), pendant un temps de réaction court, la formation du 1,1,2,2-tétraméthyldisilane par réaction d'insertion du diméthylsilylène dans le lien Si−H du DMS a été favorisée, par rapport à la formation du triméthylsilane issu de la réaction de recombinaison de radicaux libres. Toutefois, lorsque la pression était décuplée, la formation en phase gazeuse du triméthylsi-lane était prédominante. Nous avons démontré que le piégeage des intermédiaires réactifs par les hydrocarbures légers produits in situ est responsable du changement obse...

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“…Increased tungsten content was observed at the tips of the straight whiskers of the (5) W x C-β-SiC nanocomposite ( Figure 5 ). This indicates that the whiskers may have been produced via the vapor-liquid-solid (VLS) mechanism, whereas the liquid W-Si-O-C droplets formed in the reaction mixture and acted as a catalyst for the formation of SiC nano-whiskers [ 57 , 58 , 59 , 60 , 61 , 62 , 63 , 64 , 65 , 66 ]. The mechanisms of whisker formation have been discussed in an earlier publication [ 23 ].…”

Section: Resultsmentioning

confidence: 99%

WxC-β-SiC Nanocomposite Catalysts Used in Aqueous Phase Hydrogenation of Furfural

et al. 2017

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This study investigates the effects of the addition of tungsten on the structure, phase composition, textural properties and activities of β-SiC-based catalysts in the aqueous phase hydrogenation of furfural. Carbothermal reduction of SiO2 in the presence of WO3 at 1550 °C in argon resulted in the formation of WxC-β-SiC nanocomposite powders with significant variations in particle morphology and content of WxC-tipped β-SiC nano-whiskers, as revealed by TEM and SEM-EDS. The specific surface area (SSA) of the nanocomposite strongly depended on the amount of tungsten and had a notable impact on its catalytic properties for the production of furfuryl alcohol (FA) and tetrahydrofurfuryl alcohol (THFA). Nanocomposite WxC-β-SiC catalysts with 10 wt % W in the starting mixture had the highest SSA and the smallest WxC crystallites. Some 10 wt % W nanocomposite catalysts demonstrated up to 90% yield of THFA, in particular in the reduction of furfural derived from biomass, although the reproducible performance of such catalysts has yet to be achieved.

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Parameters determining crystallinity in β-SiC thin films prepared by catalytic chemical vapor deposition

Cited by 25 publications

References 13 publications

Growth and effect of deposition pressure on microstructure and electrical properties of 3C-SiC thin films deposited using methyltrichlorosilane single precursor

Growth and effect of deposition pressure on microstructure and electrical properties of 3C-SiC thin films deposited using methyltrichlorosilane single precursor

Effect of pressure on the gas-phase chemistry when using monomethylsilane and dimethylsilane in hot-wire chemical vapor deposition

WxC-β-SiC Nanocomposite Catalysts Used in Aqueous Phase Hydrogenation of Furfural

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