• Journal of the Microelectronics and Packaging Society
• /
• v.11 no.3 s.32
• /
• pp.63-70
• /
• 2004

The structural, electrical properties of $(Ba, Sr)TiO_3[BSTO]/RuO_2$ thin films were examined by the addition of amorphous BSTO layer between crystlline BSTO film and $RuO_2$ substrate. We prepared BSTO films with double-layered structure, that is, amorphous layers deposited at $60^{\circ}C$ and crystalline films. Crystalline films were prepared at 550 on amorphous BSTO layer. The thickness of the amorphous layers was varied from 0 to 170 nm. During the deposition of crystalline films, the crystallization of the amorphous layers occurred and the structure was changed to circular while crystalline BSTO films showed columnar structure. Due to insufficient annealing effect, amorphous BSTO phase was observed when the thickness of the amorphous layers exceeded 30 nm. Amorphous BSTO layer could also prevent the formation of oxygen deficient region in $RuO_2$ surface. Leakage current of total BSTO films decreased with increasing amorphous layer thickness due to structural modifications. Dielectric constant showed maxi-mum value of 343 when amorphous layer thickness was 30 nm at which the improvement by grain growth and the degradation by amorphous phase were balanced.

• Journal of the Semiconductor & Display Technology
• /
• v.4 no.3 s.12
• /
• pp.5-9
• /
• 2005

The bonding structure of organic materials such as fluorinated amorphous carbon films was classified into two types due to the chemical shifts. The electrical properties of fluorinated amorphous carbon films also showed very different effect of two types notwithstanding a very little difference. Fluorinated amorphous carbon films with the cross-link break-age structure existed large leakage current resulting from effect of the electron tunneling. Increasing the cation due to the electron-deficient group increased the barrier height of the films with the cross-link amorphous structure, therefore the electric characteristic of the final materials with low dielectric constant was also improved. The lowest dielectric constant is 2.3 at the sample with the cross-link amorphous structure.

• Journal of Korean Vacuum Science & Technology
• /
• v.2 no.1
• /
• pp.49-54
• /
• 1998

The effect of deposition paratmeters on the solid-phase crystallization of amorphous silicon films deposited by plasma-enhanced chemical vapor deposition has been investigated by x-ray diffraction. The amorphous silicon films were prepared on Si(100) wafers using SiH4 gas with and without H2 dilution at the substrate temperatures between 12$^{\circ}C$ and 38$0^{\circ}C$. The R. F. powers and the deposition pressures were also varied. After crystallizing at $600^{\circ}C$ for 24h, the films exhibited (111), (220), and (311) x-ray diffraction peaks. The (111) peak intensity increased as the substrate temperature decreased, and the H dilution suppressed the crystallization. Increasing R.F. powers within the limits of etching level and increasing deposition pressures also have enhanced the peak intensity. The peak intensity was closely related to the deposition rate, which may be an indirect indicator of structural disorder in amorphous silicon films. Our results are consistent with the fact that an increase of the structural disorder I amorphous silicon films enhances the grain size in the crystallized films.

• Korean Journal of Materials Research
• /
• v.18 no.3
• /
• pp.113-116
• /
• 2008

A 532 nm Nd-YAG laser was applied to crystallize amorphous Si thin films in order to evaluate the applicability of a Nd-YAG laser to low-temperature polycrystalline Si technology. The irradiation of a green laser was controlled during the crystallization of amorphous Si thin films deposited onto glass substrates in a sophisticated process. Raman spectroscopy and UV-Visible spectrophotometry were employed to quantify the degree of crystallization in the Si thin films in terms of its optical transmission and vibrational characteristics. The effectiveness of the Nd-YAG laser is suggested as a feasible alternative that is capable of crystallizing the amorphous Si thin films.

• Journal of the Korean Ceramic Society
• /
• v.35 no.5
• /
• pp.486-492
• /
• 1998

Silicon carbide (SiC) thin films were deposited on the porous silicon substrates by chemical vapour de-position(CVD) using MTS as a source material. The deposited films were ${\beta}$-SiC with poor crystallity con-firmed by XRD measurement. It was considered that the films showed the mixed characteistics of cry-stalline and amorphous SiC where amorphous SiC where amorphous SiC played a role of buffer layer in interface between as-dep films and Si substrate. The buffer layer reduced lattice mismatch to some extent the generally occurs when SiC films are deposited on Si. The low temperature (10K) PL (phtoluminescence) studies showed two broad bands with peaks at 600 and 720 for the films deposited at 1100$^{\circ}C$ The maximum PL peak of the crystalline SiC was observed at 600 nm and the amrophous SiC of 720 nm was also confirmed. PL peak due the amorphous SiC was smaller than that of the crystalline SiC, PL of porous Si might be disapperared due to densification during heat treatment.

• Journal of information and communication convergence engineering
• /
• v.9 no.5
• /
• pp.587-590
• /
• 2011

The absence of deep traps for electrons in the spectrum of $As_{40}Se_{30}S_30$ localized states films obtained by ion sputtering was determined. Bipolar drift of charge carriers was found in amorphous $As_{40}Se_{30}S_30$ films of chalcogenide glassy semiconductors, obtained by ion-plasma sputtering of high-frequency, unlike the films of these materials obtained by thermal evaporation.

• Journal of the Korean institute of surface engineering
• /
• v.45 no.6
• /
• pp.242-247
• /
• 2012

Yb-doped ITO (ITO:Yb) films were deposited on unheated non-alkali glass substrates by magnetron cosputtering using two cathodes (DC, RF) equipped with the ITO and $Yb_2O_3$ target, respectively. The composition of the ITO:Yb films was controlled by adjusting the RF powers from 0 W to 480 W in 120 W steps with the DC power fixed at 70 W. The ITO:Yb films had a higher crystallization temperature ($200^{\circ}C$) than that of the ITO films ($170^{\circ}C$), which was attributed to both larger ionic radius of $Yb^{3+}$ and higher bond enthalpy of $Yb_2O_3$, compared to ITO. This amorphous ITO:Yb film post-annealed at $170^{\circ}C$ showed a resistivity of $5.52{\times}10^{-4}{\Omega}cm$, indicating that a introduction of Yb increased resistivity of the ITO film. However, these amorphous ITO:Yb films showed a high etching rate, fine pattering property, and a very smooth surface morphology above the crystallization temperature of the amorphous ITO films (about $170^{\circ}C$). The transmittance of all films was >80% in the visible region.

• Proceedings of the Materials Research Society of Korea Conference
• /
• 2011.10a
• /
• pp.28.1-28.1
• /
• 2011

We deposited the carbon films on Ni substrates by thermal atomic layer deposition (th-ALD), for the first time, using carbon tetrabromide ($CBr_4$) precursors and H2 reactants at two different temperatures (573 K and 673 K). Morphology of carbon films was characterized by scanning electron microscopy (SEM). The carbon films having amorphous carbon structures were analyzed by X-ray photoemission spectroscopy (XPS) and Raman spectroscopy. As the working temperature was increased from 573 K to 673 K, the intensity of C1s spectra was increased while that of O1s core spectra was reduced. That is, the purity of carbon films containing bromine (Br) atoms was increased. Also, the thin amorphous carbon films (ALD 3 cycle) were transformed to multilayer graphene segregated on Ni layer, through the post-annealing and cooling process.

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

• The Korean Journal of Ceramics
• /
• v.6 no.2
• /
• pp.107-109
• /
• 2000

The crystallization process and the electrical properties of amorphous tin-doped indium oxide (ITO) films have been studied in contrast with those of undoped indium oxide (IO) films. Amorphous ITO and IO films were prepared by magnetron sputtering succeeded by annealing in the air at various temperatures. ITO films showed higher crystallization temperature compared with that of IO films, suggesting an excess free energy caused by the repulsion between the active donors ($Sn^{4+}$). The analysis of the electrical properties alternated with the phased annealing of films provided essential information for understanding the conduction mechanisms of ITO. It was also revealed that the amorphous IO/ITO films showed oxidation around $100^{\circ}C$ in contrast with crystalline IO/ITO films with the oxidation temperature above $200^{\circ}C$.