• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2004.04b
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• pp.133-136
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• 2004

In this study, the characteristics of 3C-SiC ohmic contact were investigated. Titanium-tungsten(TiW) films were used for contact metalization. The ohmic contact resistivity between 3C-SiC and TiW was measured by HP4155 and then calculated with the circular transmission line method(C-TLM). And also the physical properties of TiW and the interface between TiW and 3C-SiC were analyzed using XRD and AES. TiW films make a good role of a diffusion barrier and their contact properties with 3C-SiC are stable at high temperature.

• Proceedings of the Korean Vacuum Society Conference
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• 2000.02a
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• pp.80-80
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• 2000

Surface acoustic wave (SAW) devices have become more important as mobile telecommunication systems need h호-frrequency, low-loss, and down-sized components. Higher-frequency SAW divices can be more sasily realized by developing new h호-SAW-velocity materials. The ZnO/diamond/Si multilasyer structure is one of the most promising material components for GHz-band SAW filters because of its SAW velocity above 10,000 m/sec. Silicon carbide is also a potential candidate material for high frequency, high power and radiation resistive electronic devices due to its superior mechanical, thermal and electronic properties. However, high price of commercialized 6- or 4H-SiC single crystalline wafer is an obstacle to apply SiC to high frequency SAW devices. In this study, single crystalline 3C-SiC thin films were grown on Si (100) by MOCVD using bis-trimethylsilymethane (BTMSM, C7H20Si7) organosilicon precursor. The 3C-SiC film properties were investigated using SEM, TEM, and high resolution XRD. The FWHM of 3C-SiC (200) peak was obtained 0.37 degree. To investigate the SAW propagation characteristics of the 3C-SiC films, SAW filters were fabricated using interdigital transducer electrodes on the top of ZnO/3C-SiC/Si(100), which were used to excite surface acoustic waves. SAW velocities were calculated from the frequency-response measurements of SAW filters. A generalized SAW mode. The hard 3C-SiC thin films stiffened Si substrate so that the velocities of fundamental and the 1st mode increased up to 5,100 m/s and 9,140 m/s, respectively.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2009.06a
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• pp.197-198
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• 2009

This paper describes the Raman scattering characteristics of polycrystalline (poly) 3C-SiC films, which were deposited on the thermally oxidized Si(100) substrate by the atmosphere pressure chemical vapor deposition (APCVD) method according to growth temperature. TO and LO phonon modes to 2.0m thick poly 3C-SiC deposited at $1180^{\circ}C$ were measured at 794.4 and $965.7\;cm^{-1}$ respectively. From the intensity ratio of $I_{(LO)}/I_{(TO)}$ 1.0 and the broad full width half maximum (FWHM) of TO modes, itcan be elucidated that the crystallinity of 3C-SiC forms polycrystal instead of disordered crystal and the crystal defect is small. At the interface between 3C-SiC and $SiO_2$, $1122.6\;cm^{-1}$ related to C-O bonding was measured. Here poly 3C-SiC admixes with nanoparticle graphite with the Raman shifts of D and G bands of C-C bonding 1355.8 and $1596.8\;cm^{-1}$. Using TO mode of 2.0 m thick poly 3C-SiC, the biaxial stress was calculated as 428 MPa.

• Proceedings of the Korean Vacuum Society Conference
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• 1999.07a
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• pp.123-123
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• 1999

Amorphous hydrogenated silicon carbide (a-SiC:H) films were deposited at the temperature of 40$0^{\circ}C$ using plasma enhanced chemical vapor deposition. The a-SiC:H films were characterized by x-ray photoelectron spectroscopy (XPS) and nanoindentation method. By increasing the plasma power from 20W to 160W, the oxygen content of the a-SiC:H films were observed to decrease from 12.1% to 4.4%. On the other hand, the plasma power did not affect the ratio of carbon to silicon in our experiment where the 1, 3-disilabutane was used as the precursor. Microhardness of the films was observed to increase as the plasma power increased, while the elastic modulus was observed to gave a maximum value at the plasma power of 80W. Microhardness of the film is thought to be strongly affected by the content of adventitious oxygen in the film and it is concluded that the hardness of the film can be improved by increasing the plasma power.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2008.11a
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• pp.92-92
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• 2008

The surface flatness of heteroepitaxially grown 3C-SiC thin films is a key factor affecting electronic and mechanical device applications. This paper describes the surface flatness of polycrystalline 3C-SiC thin films by the gas flow control according to the location change of geometric structure. The polycrystalline 3C-SiC thin film was deposited by APCVD(Atmospheric pressure chemical vapor deposition) at $1200^{\circ}C$ using HMDS(Hexamethyildisilane : $Si_2(CH_3)_6)$ as single precursor, and 5 slm Ar as the main flow gas. According to the location of geometric structure, surface fringes and flatness changed. It shows the distribution of thickness is formed uniformly in the specific location of the geometric structure.

• Journal of Sensor Science and Technology
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• v.22 no.3
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• pp.175-180
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• 2013

This paper describes the characteristics of cubic silicon carbide (3C-SiC) films grown on a carbonized Si(100) substrate, using hexamethyldisilane (HMDS, $Si_2(CH_3)_6$) as a safe organosilane single precursor in a nonflammable $H_2$/Ar ($H_2$ in Ar) mixture carrier gas by atmospheric pressure chemical vapor deposition (APCVD) at $1280^{\circ}C$. The growth process was performed under various conditions to determine the optimized growth and carbonization condition. Under the optimized condition, grown film has a single crystalline 3C-SiC with well crystallinity, small voids, low residual stress, low carrier concentration, and low RMS. Therefore, the 3C-SiC film on the carbonized Si (100) substrate is suitable to power device and MEMS fields.

• Proceedings of the Korean Vacuum Society Conference
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• 2010.02a
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• pp.9-10
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• 2010

Since the discovery of graphene by mechanical exfoliation from graphite[1], various fabrication methods are available today such as chemical exfoliation, epitaxial graphene on SiC substrates, etc. In view of industrialization, the mechanical exfoliation method may not be an option. Epitaxial graphene on SiC substrates, in this respect, is by far more practical because the method consists of conventional thermal treatments familiar to semiconductor industry. Still, the use of the SiC substrate itself, and hence the incompatibility with the Si technology, lessens the importance of this technology in its future industrialization. In this context, we have tackled the problem of forming graphene on Si substrates (GOS). Our strategy is to form an ultrathin (~80 nm) SiC layer on top of a Si substrate, and to graphitize the top SiC layers by a vacuum annealing. We have actually succeeded in forming the GOS structure [2,3,4]. Raman-scattering microscopy indicates presence of few-layer graphene (FLG) formed on our annealed SiC/Si heterostructure, with the G ($1580\;cm^{-1}$) and the G'($2700\;cm^{-1}$) bands, both related to ideal graphene, clearly observed. Presence of the D ($1350\;cm^{-1}$) band indicates presence of defects in our GOS films, whose elimination remains as a challenge in the future. To obtain qualified graphene films on Si substrate, formation of qualified SiC films is crucial in the first place, and is achieved by tuning the growth parameters into a process window[5]. With a potential for forming graphene films on large-scale Si wafers, GOS is a powerful candidate as a key technology in bringing graphene into silicon technology.

• Journal of the Korean Crystal Growth and Crystal Technology
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• v.8 no.2
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• pp.233-239
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• 1998

SiC thin films were deposited by chemical vapor deposition method using tetramethylsilane (TMS) and hexamethyldisilane (HMDS). The chamber pressure during the deposition was kept at about 1 torr. Precursor was transported to the reaction chamber by $H_2$gas and SiC deposition was carried out at the reaction temperature of $1200^{\circ}C$. Si-wafer masked with tantalum and MgO single crystal covered with platinum and molybdenum were used as substrates. The selectivity of SiC deposition was observed by comparing the microstructure between metal (Ta, Pt, and Mo) surfaces and substrate surfaces (Si and MgO). The deposited films were identified as the $\beta-SiC$ phase by X-ray diffraction pattern. Also, the deposition -behavior of SiC on each surface was investigated by the scanning electron microscope analysis.

• Journal of Powder Materials
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• v.25 no.5
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• pp.375-378
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• 2018

Conductive and dielectric SiC are fabricated using electroless plating of Ni-Fe films on SiC chopped fibers to obtain lightweight and high-strength microwave absorbers. The electroless plating of Ni-Fe films is achieved using a two-step process of surface sensitizing and metal plating. The complex permeability and permittivity are measured for the composite specimens with the metalized SiC chopped fibers dispersed in a silicone rubber matrix. The original non-coated SiC fibers exhibit considerable dielectric losses. The complex permeability spectrum does not change significantly with the Ni-Fe coating. Moreover, dielectric constant is sensitively increased with Ni-Fe coating, owing to the increase of the space charge polarization. The improvements in absorption capability (lower reflection loss and small matching thickness) are evident with Ni-Fe coating on SiC fibers. For the composite SiC fibers coated with Ni-Fe thin films, a -35 dB reflection loss is predicted at 7.6 GHz with a matching thickness of 4 mm.

• Journal of Korean Vacuum Science & Technology
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• v.2 no.2
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• pp.107-117
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• 1998

Epitaxial undoped and Sb-doped si films have been grown on Si(001) substrates at temperatures T between 80 and 750$^{\circ}C$ using energetic Si in ultra-high-vacuum Kr+-ion-beam sputter deposition(IBSD). Critical epitaxial thicknesses te, The average thickness of epitaxial layers, in undoped films were found to range from 8nm at Ts=80$^{\circ}C$ to > 1.2 ${\mu}$m at Ts=300$^{\circ}C$ while Sb incorporation probabilities $\sigma$sb varied from unity at Ts 550$^{\circ}C$ to 0.1 at 750$^{\circ}C$. These te and $\sigma$Sb values are approximately one and one-to-three orders of magnitude, respectively, higher than reported results achieved with molecular-beam epitaxy. Plan-view and cross-sectional transmission electron microscopy, high-resolution x-ray diffraction, channeling and axial angular-yield profiles by Rutherford back scattering spectroscopy for epitaxial Si1-x Gex(001) alloy films (0.15$\leq$x$\leq$0.30) demonstrated that the films are of extremely high crystalline quality. critical layer thicknesses hc the film thickness where strain relaxation starts, I these alloys wre found to increase rapidly with decreasing growth temperature. For Si0.70 Ge0.30, hc ranged from 35nm at Ts=550$^{\circ}C$ to 650nm at 350$^{\circ}C$ compared to an equilibrium value of 8nm.