• Journal of the Korean Ceramic Society
• /
• v.36 no.1
• /
• pp.55-60
• /
• 1999

${\beta}$-SiC thin film was deposited on a Si substrate without buffer layer using a single precursor of Hexamethyldisilane (Si2(CH3)6) by chemical vapor deposition method. HCI gas was introduced into hexamethyldisilane /H2 gas mixture, and the feeding schedule of HCI and precursor gases was modified in order to enhance the selectivity of SiC deposition between a Si substrate and a SiO2 mask. The effect of HCI gas on the surface roughness of the SiC film was investigated and typical electrical properties of the SiC film were also investigated by Hall measurement.

• The Korean Journal of Ceramics
• /
• v.3 no.3
• /
• pp.163-168
• /
• 1997

Most of heteroepitaxial $\beta$-SiC thin films have been successfully grown on Si(100) adapting a carburizing process, by which a few atomic layers of substrate surface is chemically converted to very thin SiC layer using hydrocarbon gas sources. Using an organo-silicon precursor, bis-trimethylsilymethane (BTMSM, [$C_7H_{20}Si_2$]), heteropitaxial $\beta$-SiC thin films were successfully grown directy on Si substrate without a carburized buffer layer. The defect density of the $\beta$-SiC thin films deposited without a carburized layer was as low as that of $\beta$-SiC films deposited on carburized buffer layer. In addition, void density was also reduced by the formation of self-buffer layer using BTMSM instead of carburized buffer layer. It seems to be mainly due to the characteristic bonding structure of BTMSM, in which Si-C was bonded alternately and tetrahedrally (SiC$_4$).

• Proceedings of the Korean Ceranic Society Conference
• /
• 1986.12a
• /
• pp.287-304
• /
• 1986

High quality monocrystalline $\beta$-SiC thin films were grown via two-step process of conversion of the Si(100) surface by reaction with $C_2H_4$ and the subsequent chemical vapor deposition (CVD) at $1360^{\circ}C$ and 1 atm total pressure. Four dopants, B and Al and p-type, and N and P for n-type, were also incorporated into monocrystalline $\beta$-SiC thin films during the CVD growth process. IR and Raman spectroscopies were used to evaluate the quality of the undoped $\beta$-SiC thin films and to investigate the effects of dopants on the structure of the doped $\beta$-SiC thin films. The changes in the shape of IR and Raman spectra of the doped thin films due to dopants were observed. But the XTEM micrographs except for the B-doped and annealed films showed the same density and distribution of stacking faults and dislocations as was seen in the undoped samples, The IR and Raman spectra of the B-doped and annealed films showed the broad and weak bands and one extra peak at the 850 $cm^{-1}$ respectively. The SAD pattern and XTEM micrograph of the B-doped and annealed film provided the evidence for twinning.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
• /
• v.20 no.2
• /
• pp.156-161
• /
• 2007

This paper describes the characteristics of polycrystalline ${\beta}$ or 3C (cubic)-SiC (silicon carbide) thin films heteroepitaxailly grown on Si wafers with thermal oxide. In this work, the poly 3C-SiC film was deposited by APCVD (atmospheric pressure chemical vapor deposition) method using HMDS (hexamethyildisilane: $Si_{2}(CH_{3}_{6})$ single precursor. The deposition was performed under various conditions to determine the optimized growth conditions. The crystallinity of the 3C-SiC thin film was analyzed by XPS (X-ray photoelectron spectroscopy), XRD (X-ray diffraction) and FT-IR (fourier transform-infrared spectometers), respectively. The surface morphology was also observed by AFM (atomic force microscopy) and voids or dislocations between SiC and $SiO_{2}$ were measured by SEM (scanning electron microscope). Finally, depth profiling was invesigated by GDS (glow discharge spectrometer) for component ratios analysis of Si and C according to the grown 3C-SiC film thickness. From these results, the grown poly 3C-SiC thin film is very good crystalline quality, surface like mirror and low defect. Therfore, the poly 3C-SiC thin film is suitable for extreme environment, Bio and RF MEMS applications in conjunction with Si micromaching.

• Journal of the Korean Ceramic Society
• /
• v.34 no.8
• /
• pp.825-833
• /
• 1997

Silicon carbide films were deposited by low pressure chemical vapor deposition(LPCVD) using MTS(CH3SICl3) in hydrogen atmosphere on (100) Si substrate. To prevent the unstable interface from being formed on the substrate, the experiments were performed through three deposition processes which were the deposition on 1) as received Si, 2) low temperature grown SiC, and 3) carbonized Si by C2H2. The microstructure of the interface between Si substrates and SiC films was observed by SEM and the adhesion between Si substrates and SiC films was measured through scratch test. The SiC films deposited on the low temperature grown SiC thin films, showed the stable interfacial structures. The interface of the SiC films deposited on carbonized Si, however, was more stable and showed better adhesion than the others. In the case of the low temperature growth process, the optimum condition was 120$0^{\circ}C$ on carbonized Si by 3% C2H2, at 105$0^{\circ}C$, 5 torr, 10 min, showed the most stable interface. As a result of XRD analysis, it was observed that the preferred orientation of (200) plane was increased with Si carbonization. On the basis of the experimental results, the models of defect formation in the process of each deposition were compared.

• Journal of the Korean Crystal Growth and Crystal Technology
• /
• v.9 no.1
• /
• pp.14-19
• /
• 1999

Using a single precursor of hexamethyldisilane $(Si_{2}(CH_{3})_{6})$, $\beta$-SiC film was successfully deposited on a Si substrate at $1100^{\circ}C$ by a chemical vapor deposition method. Selectivity of SiC deposition on a Si substrate partially covered with a masking material was investigated by introducing HCl gas into hexamethyldisilane/$H_{2}$ gas system during the deposition. The schedule of the precursor and HCl gas flows was modified so that the selectivity of SiC deposition between a Si substrate and a mask material should be improved. It was confirmed that the selectivity of SiC deposition was improved by introducing HCl gas. Also, the pulse gas flow technique was effective to enhance the selectivity.

• Journal of the Korean Ceramic Society
• /
• v.32 no.6
• /
• pp.697-702
• /
• 1995

The rough growth surfaces of diamond films fabricated by the hot filament CVD were polished using thermomechanical polishing method. And then, its application to the optical windows was discussed through the measurement of transmittance in the range of infrared radiation and analysis of surfaces structure. The results were compaerd with those of the films polished with conventional mechanicla polishing. The transmittance of the mechanically polished film reached 57~66% over the whole range from 500 to 4000 cm-1. But the transmittance of the film polished with thermomechanical polishing method was reduced below 35%. This decrease in transmittance was due to both the graphitization of diamond on the polished surface and the growth of $\beta$-SiC at diamond/Si interface during polishing. The residual Fe in hte thermomechanically polished surface was confirmed by SIMS analysis. This Fe played the role of the graphitization of near surface region of the diamond film.

• Applied Chemistry for Engineering
• /
• v.8 no.4
• /
• pp.589-594
• /
• 1997

Superconducting $YBa_2Cu_3O_y$ thin films were prepared at the deposition temperature of $650^{\circ}C$ under oxygen partial pressure of 0.0126 Torr on Si(111) and SrTiO3(100) substrates by chemical vapor deposition technique using $\beta$-diketonates of Y, Ba and Cu as source materials. The thin film fabricated on $SrTiO_3(100)$ had a $T_{c,onset}$ of 91K and $T_{c.0}$ of 87K. The thin film prepared on Si(111) had a $T_{c,onset}$ of 91K but didn't have a $T_{c.0}$ at liquid nitrogen boiling point(77.3K). Dense and two-dimensionally well alligned microstructure was developed for the film deposited on $SrTiO_3(100)$ substrate whereas a relatively porous and randomly distributed microstructure was developed for the film prepared on Si(111) substrate.

• Journal of the Korean Ceramic Society
• /
• v.32 no.7
• /
• pp.793-798
• /
• 1995

The relaxation of the intrinsic stresses in the diamond films fabricated by the hot filament CVD was studied, and it was confirmed that the tensile intrinsic stresses in the films could be controlled without any degradation in the quality of the diamond films. The tensile intrinsic stresses in the films decreased from 2.97 to 1.42 GPa when the substrate thickness increased from 1 to 10mm. This result showed that the residual stress was affected by the substrate thickness as well as by the interaction between grains. Applying of ＋50 V between the W filament and the Si substrate during deposition, the tensile intrinsic stress in the film deposited at 0 V was decreased from 2.40 GPa to 0.71 GPa. Such large decrease in the tensile intrinsic stress was due to $\beta$-SiC which acted as a buffer layer for the stress relaxation. However, the application of the large voltage above ＋200V resulted in the change of quality of the diamond film, and nearly had no effect on relaxation in the tensile intrinsic stress.

• Korean Chemical Engineering Research
• /
• v.53 no.2
• /
• pp.247-252
• /
• 2015

ZSM-5 crystals grew on the surface of ${\alpha}$-SiC and ${\beta}$-SiC particles by hydrothermal synthesis method. SiC particles which were > $50{\mu}m$ of size were used, and oxide layer were developed on the surface of the particles to induce growth of ZSM-5 from the surface. Then, synthesis time and temperature condition were considered growing ZSM-5. In this study, oxide layer was formed on ${\beta}$-SiC at $900^{\circ}C$ in air, and it was controlled to grow ZSM-5 grew from the ${\beta}$-SiC surface with $150^{\circ}C$ synthesis condition. This is due to Si-O-Si or Si-O-Al bond, which is basic framework of ZSM-5 can be easily formed, from the silicon oxide film on the surface of ${\beta}$-SiC. When the synthesis temperature was $200^{\circ}C$, the size of ZSM-5 was increased, and it covered much area of the SiC surface with better crystal shapes with longer synthesis time.