• Journal of the Korean Ceramic Society
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• v.46 no.1
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• pp.10-15
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• 2009

We have fabricated silicon-rich silica thin films via RF magnetron sputtering using a SiO target. Thickness evolution and microstructure change of such $SiO_x$ (1$SiO_x$ thin films turned out to be mainly responsible for the increase of refractive index.

• Tribology and Lubricants
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• v.11 no.5
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• pp.20-25
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• 1995

Diamond films were prepared by a hot filament vapor deposition onto polycrystal silicon nitride substrates. Different kinds of silicon nitride containing CaO and $Fe_{2}O_{3}$ were manufactured to investigate the impurity effect of substrate on the morphology of diamond films and their wear behaviors. Nucleation rates and morphologies of diamond films deposited on various kinds of silicon nitride were compared. The highest nucleation rate was observed in a substrate containing 1% of CaO. Wear tests were performed with a silicon nitride ball on the disk geometry to investigate the tribological behavior of diamond film against silicon nitride. This study demonstrated that different morphologies of diamond film due to substrate impurities produced different wear behavior against silicon nitride.

• Journal of the Korean Crystal Growth and Crystal Technology
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• v.3 no.1
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• pp.59-65
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• 1993

The boron-doped polycrystalline silicon films which can be used in pressure sensors were fabricated in a high-vacuum resistance heating evaporator. Poly-Si films were deposited on quartz substrates at various temperatures and the boron was doped to the silicon film in a diffusion furnace using BN wafer. The silicon films deposited at $500^{\circ}C$ was amorphous, began to show crystalline at $600^{\circ}C$, and became polycrystalline at $700^{\circ}C$. After doping boron at $900^{\circ}C$for 10 minutes, the resistivity of the films was in the range of $0.1{\Omega}cm~1.5{\Omega}cm$, the boron density was $9.4\times10^{15}~2.1\times{10}^{17}cm^{-3}$, and the grain size was $107{\AA}~191{\AA}$.

• Journal of the Korean Institute of Telematics and Electronics A
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• v.32A no.1
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• pp.179-184
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• 1995

Phosphorous was deped in silicon thin films by Ion Mass Doping and Changes in the electrical resistance with respect tko heat treatments were investigated. SOI(Silicon On Insulator) thin films which contain few grain boundaries prepared by ZMR(Zone Melting Recrystallization) of polysilicon films, polysilicon films which have about 1500 $A^{\rarw}$ of grain size prepared by LPCVD at 625.deg. C, and amorphous silicon thin films prepared by LPCVD at low temperature were used as substrates and thermal behavior of phosphorous after RTA(Rapid Thermal Annealing) and furnace annealing was carefully studied. Amorphous thin films showed about 10$^{6}$ .OMEGA./ㅁbefore any heat treatment, while polycrystalline and SOI films about 10$^{3}$.OMEGA./¤. All these films, however, showed about 10.OMEGA./ㅁafter furnace annealing at 700.deg. C for 3hrs and RTA showed about the same trend. Films with grain boundaries showed a certain range of heat treatment which rendered increase of the electrical resistance upon annealing, which could not be observed in amorphous films and segregation of doped phosphorous by diffusion with annealing was thought to be responsible for this abnormal behavior.

• Electrical & Electronic Materials
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• v.7 no.2
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• pp.94-99
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• 1994

The purpose of this work is to investigate the interface characteristics of hydrogenated amorphous silicon thin films prepared by PECVD and photo-induced CVD and to examine the annealing effects of ultraviolet irradiation on hydrogenated amorphous silicon thin films which were degraded by visible light illumination. The interface layer thickness of films deposited by photo-induced CVD was about 600-900.angs. while that by PECVD was about 1000-1300.angs.. These results can show that the quality of interface layer in photo induced CVD film is better than that in PECVD sample. The electrical properties are improved by ultraviolet irradiation on visible light soaked a-Si:H films using photo-CVD light sources, probably due to the fact that UV generates phonons in a-Si:H films and anneal the meta stable defects.

• Proceedings of the Materials Research Society of Korea Conference
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• 2006.05a
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• pp.16.1-16.1
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• 2006

• Journal of Integrative Natural Science
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• v.6 no.4
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• pp.244-250
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• 2013

Three types of functionalized flexible optical composite films based on Bragg structure porous silicon interferometer have been successfully fabricated by casting a toluene solution of polystyrene onto the free-standing porous silicon. The optical properties of composite films are measured. Surface functionalization of porous silicon is determined by FT-IR measurement. Reflectance and transparence properties of composite films are measured for the possible application of tunable optical filter and indicate that the transmission peak occurred at the identical location where the reflection peak appeared.

• Journal of the Korean Vacuum Society
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• v.4 no.S2
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• pp.64-68
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• 1995

Silicon films were deposited at $430^{\circ}C$ by remote plasma chemical vapor deposition(RPECVD) with a gas mixture of $Si_2H_6/SiF_4/H_2$. The silicon films deposited without and with $SiF_4$ were characterized using atomic force microscopy(AFM), transmission electron microscopy(TEM) and X-ray diffraction(XRD). Both silicon films have the same rugged surface morphology, but, the silicon film deposited with $SiF_4$ exhibits more rugged. The silicon film deposited without $SiF_4$ is amorphous, whereas the silicon film deposited with $SiF_4$ is polycrystalline with very small needle-like grains which are perpendicular to the substrate and uniformly distributed in the thickness of the film. The silicon film deposited with $SiF_4$ was found to have a preferred orientation along the growth direction with the<110> of the film parallel to the <111> of the substrate. The effect of $SiF_4$ during RPECVD was discussed.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2010.06a
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• pp.365-365
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• 2010

In this paper, silicon nitride thin films with different silane and ammonia gas ratios were deposited and characterized for the antireflection and passivation layer of high efficiency single crystalline silicon solar cells. As the flow rate of the ammonia gas increased, the refractive index decreased and the band gap increased. Consequently, the transmittance increased due to the higher band gap and the decrease of the defect states which existed for the 1.68 and 1.80 eV in the SiNx films. The reduction in the carrier lifetime of the SiNx films deposited by using a higher $NH_3/SiH_4$ flow ratio was caused by the increase of the interface traps and the defect states in/on the interface between the SiNx and the silicon wafer. The silicon and nitrogen rich films are not suitable for generating both higher carrier lifetimes and transmittance. These results indicate that the band gap and the defect states of the SiNx films should be carefully controlled in order to obtain the maximum efficiency for c-Si solar cells.

• Proceedings of the KSME Conference
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• 2007.05b
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• pp.2453-2458
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• 2007

The performance of polysilicon thin film transistor (p-Si TFT) has an important role in the operation of active matrix liquid crystal displays. To fabricate the p-Si TFTs that have uniform characteristics, understanding of the recrystallization mechanism of silicon is crucial. Especially, the analysis of the transient temperature variation and the liquid-solid interface motion is required to find the mechanism. The thermal conductivity is one of the most important parameters to understand the mechanism. In this work, a KrF eximer laser beam was irradiated to amorphous silicon thin films. We measured the transient reflectivity at the wavelength of 633 nm. We carried out the numerical simulation of one dimension conduction equation so that we determined the most well-fitted thermal conductivity by comparing the numerically obtained transient reflectivity with the experimentally measured one. The experimentally determined thermal conductivity of amorphous silicon thin films is 1.5 W/mK.