• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2000.07a
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• pp.747-750
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• 2000

In this work, we investigated the dependence of optical and electrical properties of amorphous hydrogenated SiC (a-SiC:H) films on annealing temperature(T$\sub$a/). The a-SiC:H films were deposited by PECVD(plasma enhanced vapor deposition) on coming glass, p-type Si(100) wafer using SiH$_4$+CH$_4$+N$_2$gas mixture. The experimental results have shown that the optical energy band gap(E$\sub$g/) of the a-SiC thin films unchanged in the range of T$\sub$a/ from 400$^{\circ}C$ to 600$^{\circ}C$. The Raman spectrum of the thin films, annealed at high temperatures, has shown that 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 Electrical and Electronic Material Engineers
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• v.17 no.5
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• pp.526-529
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• 2004

The nematic liquid crysta](NLC) aligning capabilities using a-C:H thin film deposited at the three kinds of rf bias condition were investigated. A high pretilt angle of NLC on low substrate rf bias applied a-C:H thin films was observed and the low pretilt angle of the NLC on high substrate rf bias applied a-C:H thin films was observed. Consequently, the high NLC pretilt angle and the good aligning capabilities of LC alignment by the IB alignment method on the a-C:H thin film deposited at 1 W rf bias condition can be achieved. It is considered that pretilt angle of the NLC may be attributed to substrate rf bias condition and IB energy time. Therefore, LC alignment is affected by topographical structure forming strong IB energy.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2002.07b
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• pp.839-844
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• 2002

This letter focuses on the liquid crystal alignment characteristics according to the properties of hydrogenated amorphous carbon(a-C:H) thin film deposited by RPECVD(Remote Plasma Enhanced Chemical Vapor Deposition) method using $C_2H_2$ and He gases. The properties of the deposited thin films were controlled by the ion beam irradiation time and ion beam energy. The results show that not ion beam energy but ion beam irradiation time plays an important role in the properties of a-G:H thin films. As the ion beam irradiation time increases, not only the sp2 concentration in a-G:H thin films but also liquid crystal pretilt angle was varied.

• Korean Journal of Crystallography
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• v.3 no.2
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• pp.98-110
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• 1992

B-SiC thin films were fabricated on Si(100) substrate under 1 atom by fVD. The effects of deposition conditions on the growth and the properties especially crystallinity and prefer ential alignment of these thin films were investigated. SiH4 and CH4 were used as source gases and H2 as Carrier gas. Th9 growth Of B-SiC thin films with changing parameters such as the growth temperature, the ratio of source gases (SiH4/CH4 ) and the total amount of source gases. The grown thin films were characterized by using SEM, a -step, XRD, Raman Spectro- scopy and TEM. Chemical conversion process improved the quality of thin films due to the formation of SiC buffer layer. The crystallinity of SiC thin films was improved when the growth temperature was higher than l150t and the amount of CH4 exceeded that of SiH4. The better crystallinity, the better alignment to the crystalline direction of substates. TEM analyses of the good quality thin films showed that the grain size was bigger at the surface than at the interface and the defect density is not depend on the ratio of the source gases.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2002.05c
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• pp.93-96
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• 2002

In this study, PZT thin films were fabricated using sol-gel processing onto Si/$SiO_2$/Ti/Pt substrates. PZT sol with different Zr/Ti ratio(20/80, 30/70, 40/60, 52/48) were prepared, respectively. The films were fabricated by using the spin-coating method on substrates. The films were heat treated at $450^{\circ}C$, $650^{\circ}C$ by rapid thermal annealing(RTA). The preferred orientation of the PZT thin films were observed by X-ray diffraction(XRD), and Scanning electron microscopy(SEM). All of the resulting PZT thin films were crystallized with perovskite phase. The fine crystallinity of the films were fabricated. Also, we found that the ferroelectric properties from the dielectric constant of the PZT thin films were over 600 degrees, P-E hysteresis constant. And the leakage current densities of films were lower than $10^{-8}A/cm^2$. It is concluded that the PZT thin films by sol-gel process to be convinced of application for ferroelectric memory device.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.17 no.3
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• pp.278-282
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• 2004

The Hydrogenated amorphous carbon(a-C:H) thin films are deposited on silicon with a close field unbalanced magnetron(CFUBM) sputtering systems. The experimental data are obtained on the depositon rate and physical properties of a-C:H films using DC bias voltage and Ar/C$_2$H$_2$ pressure. The depostion rate and the surface roughness decrease with DC bias voltage, but the hardness of the thin films increases with DC bias voltage. And the position of G-peak moves to lower wavenumber indicating an increase in diamond-like carbon characteristics with the lower Ar/C$_2$H$_2$ pressure.

• 한국정보디스플레이학회:학술대회논문집
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• 2005.07a
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• pp.330-333
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• 2005

We investigated the liquid crystal (LC) alignment phenomena using a-C:H and a-C:F:H thin films. Homogeneous alignment is obtained using ion beam treated hydrogenated amorphous carbon (a-C:H) thin films. Homeotropic alignment is obtained using F treated a-C:H thin films, namely, fluorinated amorphous carbon (a-C:F:H) thin films. We investigated the relationship between the surface properties of amorphous carbon based alignment layer and LC alignment phenomena.

• Proceedings of the Korean Institute of Surface Engineering Conference
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• 2003.05a
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• pp.53-53
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• 2003

Plasma polymerized organic thin films were deposited on Si(100) glass and metal substrates using thiophene and ethylcyclohexane precursors by PECVD method. In order to compare electrochemical properties of the as-grown thin films, the effects of the RF plasma power in the range of 30~100 W. AFM showed that the polymer films with smooth surface and sharp interface could be grown under various deposition conditions. Impedance analyzer was utilized for the determination of I-V curve for leakage current density and C-V for dielectric constants, respectively. To obtain C-V curve, we used a MIM structure of metal(Al)-insulator(plasma polymerized thin film)-metal(Pt) structure. Al as the electrode was evaporated on the thiophene films that grew on Pt coated silicon substrates, and the dielectric constants of the as-grown films were then calculated from C- V data measured at 1MHz. From the electrical property measurements such as I-V and C-V characteristics, the minimum dielectric constant and the best leakage current of thiophene thin films were obtained to be about 3.22 and $1{\;}{\times}10^{-11}{\;}A/cm^2$. However, in case of ethylcyclohexane thin films, the minimum dielectric constant and the best leakage current were obtained to be about 3.11 and $5{\;}{\times}10^{-12}{\;}A/cm^2$.

• Journal of the Korean Ceramic Society
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• v.35 no.9
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• pp.969-973
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• 1998

Pb(Zr, Ti)O3 (PZT) (Zr:Ti= 52: 48) thin films were prepared on MgO(100) substrates by dipping-py-rolysis process using metal naphthenates as starting materials. Thin films were fabricated by spin coating technique and the precursor films were prefired at 20$0^{\circ}C$ in air for 0.5, 1, 2, 3, and 24 h followed by final heat treatment at 75$0^{\circ}C$ for 30min. Film prefired for 24 h lost orientational properties and pole figure analysis showed the lost of the epitaxial relationship between the films and substrate while highly a/c-axis oriented thin films were obtained for the samples prefired for 1, 2, and 3h.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2002.07b
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• pp.749-751
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• 2002

$(Pb_{1-x}Sr_x)TiO_3$ $(0.6{\leq}x{\leq}0.8)$ thin films were prepared by the MOD method for tunable microwave device application and their characteristics were investigated as a function of Sr content(x) and applied field. Thin films showed a homogeneous microstructure and the tetragonality(c/a) was slightly decreased with increasing Sr content. With increasing Sr content, Curie temperature of the thin films showed a decreasing tendency. For the PST thin films, the dielectric constant at room temperature, Tc, and $tan{\delta}$ were 750~1900, $-70^{\circ}{\sim}-30^{\circ}C$ and 0.025~0.04, respectively.