• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.13 no.10
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• pp.817-821
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• 2000

In this work, we have investigated the dependence of annealing temperature(T$\_$a/) on optical and electrical properties of amorphous hydrogenated SiC(a-SiC:H) films. The a-SiC:H films were deposited on corning glass and p-type Si(100) wafer by PECVD (plasma enhanced vapor deposition) using SiH$_4$+CH$_4$+N$_2$ gas mixture. The experimental results have shown that the optical energy band gap(E$\_$opt/)of the thin films annealed at high temperatures have shown that the graphitization of carbon clusters and micro-crystalline silicon occurs. The current-voltage characteristics have shown good electrical properties at the annealed films.

• Journal of the Korean institute of surface engineering
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• v.48 no.3
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• pp.126-130
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• 2015

A high-pressure depletion method using plasma chemical vapor deposition (CVD) is often used to deposit hydrogenated microcrystalline silicon (${\mu}c-Si:H$) films of a low defect density at a high deposition rate. To understand proper deposition conditions of ${\mu}c-Si:H$ films for a high-pressure depletion method, Si films were deposited in a combinatorial way using a multi-hollow discharge plasma CVD method. In this paper the substrate temperature dependence of ${\mu}c-Si:H$ film properties are demonstrated. The higher substrate temperature brings about the higher deposition rate, and the process window of device quality ${\mu}c-Si:H$ films becomes wider until $200^{\circ}C$. This is attributed to competitive reactions between Si etching by H atoms and Si deposition.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2007.11a
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• pp.134-135
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• 2007

Growth of cubic SiC has been carried out on oxided Si substrate using atmospheric pressure chemical vapor deposition (APCVD). Hexamethyldisilane (HMDS) was used as the single precursor and nonflammable mixture of Ar and $H_2$ was used as carrier gas. Epitaxial growth had performed depositions under the various $H_2$ conditions which were adjusted from 0 to 100 seem. The effects of $H_2$ was characterized by surface roughness, thickness uniformity, films quality and elastic modulus. Thickness uniformity and films quality were performed by SEM. Surface roughness and elastic modulus were investigated by AFM and Nano-indentor, respectively. According to the $H_2$ flow rate, Poly 3C-SiC thin film quality was improved not only physical but also mechanical properties.

• Journal of the Korean institute of surface engineering
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• v.34 no.5
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• pp.503-509
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• 2001

Thin films of hydrogenated amorphous silicon (a-Si : H) and hydrogenated amorphous silicon carbide (a-SiC:H) of different compositions were deposited on Si(100) wafer and glass by RF plasma-enhanced chemical vapor deposition (RF-PECVD). In the present work, we have investigated the effects of the RF power on the properties, such as optical band gap, transmittance and crystallinity. The Raman data show that the a-Si:H material consists of an amorphous and crystalline phase for the co-presence of two peaks centered at 480 and $520 cm^{-1}$ . The UV-VIS data suggested that the optical energy band gap ($E_{g}$ ) is not changed effectively with RF power and the obtained $E_{g}$(1.80eV) of the $\mu$c-Si:H thin film has almost the same value of a-Si:H thin film (1.75eV), indicating that the crystallity of hydrogenated amorphous silicon thin film can mainly not affected to their optical properties. However, the experimental results have shown that$ E_{g}$ of the a-SiC:H thin films changed little on the annealing temperature while $E_{g}$ increased with the RF power. The Raman spectrum of the a-SiC:H thin films annealed at high temperatures showed that graphitization of carbon clusters and microcrystalline silicon occurs.

• Journal of the Institute of Electronics Engineers of Korea SD
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• v.46 no.6
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• pp.1-5
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• 2009

Analytical expressions for breakdown voltage and specific on-resistance of 6H-SiC PN diodes have been derived successfully by extracting an effective ionization coefficient from ionization coefficients for electron and hole in 6H-SiC. The breakdown voltages induced from our analytical model are compared with experimental results. The variation of specific on-resistance as a function of doping concentration is also compared with the one reported previously. Good fits with experimental results are found for the breakdown voltage within 10% in error for the doping concentration in the range of $10^{15}{\sim}10^{18}cm^{-3}$. The analytic results show good agreement with the numerical data for the specific on-resistance in the region of $5{\times}10^{15}{\sim}10^{16}cm^{-3}$.

• 한국신재생에너지학회:학술대회논문집
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• 2010.06a
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• pp.99.2-99.2
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• 2010

This paper investigates the dependence of a-Si:H/c-Si passivation and heterojunction solar cell performances on various cleaning processes of silicon wafer and surface morphology. It is observed that passivation quality of a-Si:H thin-films on c-Si wafer highly depends on wafer surface conditions. The MCLT(Minority carrier life time) of wafer incorporating intrinsic (i) a-Si:H as a passivation layer shows sensitive variation with cleaning process and surface morpholgy. By applying improved cleaning processes and surface morphology we can obtain the MCLT of $200{\mu}sec$ after H-termination and above 1.5msec after i a-Si:H thin film deposition, which has implied open circuit voltage of 0.720V.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.26 no.12
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• pp.863-866
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• 2013

SiC crystal ingots were grown on 6H-SiC dual-seed crystals with different surface roughness and different seed orientation by a PVT (Physical Vapor Transport) method. 4H and 15R-SiC were grown on seed crystal with high root-mean-square (rms) value. The polytype of grown crystal on the seed crystal with lower rms value was confirmed to be 6H-SiC. On the other hand, all SiC crystals grown on seed crystals with different seed orientation were proven to be 6H-SiC. The surface roughness of seed crystals had no effect on the crystal structure of the grown crystals. However, the crystal quality of 6H-SiC single crystals grown on the on-axis seed were revealed to be slightly better than that of 6H-SiC crystal grown on the off-axis seed.

• Proceedings of the International Microelectronics And Packaging Society Conference
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• 2002.11a
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• pp.73-77
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• 2002

Characteristics of Cu/Si/Cu ohmic contacts to n-type 4H-SiC were investigated systematically. The ohmic contacts were formed by rf sputtering of multi layer Cu/Si/Cu sputtered sequentially. The annealings were peformed With 2-Step using RTP in vacuum ambient. The specific contact resistivity($\rho$c), sheet resistance(Rs), contact resistance(Rc), transfer length(L$_{T}$) were calculated from resistance(R$_{T}$) versus contact spacing(d) measurements obtained from TLM(transmission line method) structure. Best results were obtained for a sample annealed at vacuum as $\rho$c = 1.0x10$^{-6}$ $\Omega$$\textrm{cm}^2$, Rc = 2$\Omega$ and L$_{T}$ = 1${\mu}{\textrm}{m}$. The physical properties of contacts were examined using XRO and AES. The results showed that copper silicide was formed on SiC and Cu was migrated into SiC.o SiC.

• Proceedings of the KIEE Conference
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• 2003.07c
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• pp.1592-1594
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• 2003

This paper presents the deposition and characterization of microcrystalline silicon(${\mu}c$-Si:H) films by HWCVD(Hot-wire Chemical Vapor Deposition) method at low substrate($300^{\circ}C$). The filament temperature, pressure and $SiH_4$ concentration were determined to be a critical parameter for the deposition of poly-Si films. Series A was deposited under the conditions of $1380^{\circ}C$(Tf), 100 mTorr and $2{\sim}10%\{SC:SiH_4/(SiH_4+H_2)\}$ for 60 min. Series B was deposited under the conditions of $1400{\sim}1450^{\circ}(T_f)$, 30 mTorr and $2{\sim}12%$(SC) for 60 min. The physical characteristics were measured by Raman and FTIR spectroscopy, dark and photoconductivity measurements under AM1.5 illumination.

• Journal of the Korean institute of surface engineering
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• v.29 no.6
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• pp.797-802
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• 1996

Hydrogenated amorphous silicon carbide (a-SiC:H) films have been deposited on unheated substrates by low frequency (50Hz) plasma using $SiH_4+CH_4+H_2$ gas mixtures. Deposition rate, refractive index, optical band gap, Vickers hardness and IR spectrum of the deposited a -SiC:H films have been measured for various rations of gas flow rates k(=$CH_4/SiH_4$, 0.5k4) with a constant $H_2$ flow rate (100sccm). As k increases, the deposition rate of the a-SiC:H films increases up to the maximum value of about 220nm/h at k=2.5, and then it decreases. The refractive index of the films was 2.6 for k=2.5, while the optical band gap of the films was 3.3eV for k=2.2. The maximum value of Vickers hardness of the films was 1500Hv at k=1. The infrared transmission measurement shows that the films contain both Si-C and Si-$CH_3$ bonds.