• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2000.07a
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• pp.395-398
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• 2000

Reactive radio frequency (RF)magnetron sputter with incident angle has been used to deposit AlN thin film on a crystalline Si substrate. (002)Preferred orientation of AlN thin film has been obtained at low sputtering pressure. Also it has been shown that depostion rate of AIN thin film is affected by fraction Ar and $N_2$ partial pressure. But substrate temperature didn't affect depostion rate of AIN thin film . As sputtering pressure increased preferred orientation degraded. The internal stress changed from tensile stress to compressive stress as fraction of $N_2$ partial pressure increased. At low nitrogen partial pressure cermet$^{[1]}$ AIN thin film is obtained.

• Bulletin of the Korean Chemical Society
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• v.32 no.11
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• pp.4027-4034
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• 2011

$CaCO_3$ crystalline structures having novel assemblies were in situ fabricated as analogs of naturally occurring proteins and polysaccharides for biomineralization. The calcite crystal was mineralized in a poly(vinyl alcohol)-$Ca^{2+}$ complex film immersed in a $Na_2CO_3$ solution containing poly(aspartic acid). The morphology and size of the $CaCO_3$ crystals were tuned by varying the concentration of poly(aspartic acid). The mechanisms of their nucleation orientation and formation were investigated experimentally and through molecular dynamics (MD) simulations in order to obtain a better understanding of the interactions between the polymers and the crystal at the molecular level. Both the MD results and experimental results indicate that the interaction between PVA and calcite mainly depends on the concentration of the polymer. The novel approach proposed herein for the fabrication of inorganic crystalline assembly structures can be used to fabricate precise crystalline structures.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2002.05a
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• pp.42-45
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• 2002

General wheel mark in mono-crystalline silicon wafer finding is able to be expected because it depends on radius ratio and angular velocity ratio of wafer and wheel. The pattern is predominantly determined by the contour of abrasive grits resulting from a relative motion. Although such a wheel mark is made uniform pattern if the process parameters are fixed, sub-surface defect is expected to be distributed non-uniformly because of characteristic of mono-crystalline silicon wafer that has diamond cubic crystal. Consequently it is considered that this phenomenon affects the following process. This paper focused on kinematic analysis of wafer grinding process and simulation program was developed to verify the effect of process variables on wheel mark. And finally, we were able to predict sub-surface defect distribution that considered characteristic of mono-crystalline silicon wafer

• Journal of the Korean Society of Manufacturing Process Engineers
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• v.12 no.5
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• pp.30-35
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• 2013

In order to increase cell efficiency in crystalline silicon solar cell, reduction of light reflection is one of the essential problem. Until now silicon wafer was textured by wet etching process which has random patterns along crystal orientation. In this study, high aspect ratio patterns are manufactured by nano imprint process and reflectance could be minimized under 1%. After that, screen printed solar cell was fabricated on the textured wafer and I-V characteristics was measured by solar simulator. Consequently cell efficiency of solar cell fabricated using the wafer textured by nano imprint process increased 1.15% than reference solar cell textured by wet etching. Internal quantum efficiency was increased in the range of IR wave length but decreased in the UV wavelength. In spite of improved result, optimization between nano imprinted pattern and solar cell process should be followed.

• Proceedings of the Korean Vacuum Society Conference
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• 2013.08a
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• pp.192.2-192.2
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• 2013

Crystalline order and surface stability of 1,4,5,8,9,11-hexaazatriphenylene-hexanitrile (HATCN) thin films on organic surface were investigated using grazing incidence wide angle x-ray scattering and x-ray reflectivity measurements. In the initial growth regime (less than 20 nm), HATCN molecules were stacked to low crystalline order with substantial amorphous phase. Meanwhile, a thicker film with 50 nm thickness showed high crystalline order of hexagonal phase with three different orientational domains. The domain distribution was quantitatively obtained as a function of tilted angle. By an organic-inorganic interface formation of IZO/HATCN thin film from an indium zinc oxide (IZO) electrode deposition, the surface stability of HATCN film was investigated and the sharp interface was confirmed by the x-ray reflectivity measurement.

• Journal of the Korean Ceramic Society
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• v.41 no.2
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• pp.106-110
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• 2004

Nickel oxide (NiO) thin films were prepared on Si(100) substrates at room temperature by RF magnetron sputtering using a NiO target. The effects of oxygen flow ratio for the plasma gas on the preferred orientation and surface morphology of the NiO films were investigated. Highly crystalline NiO film with (100) orientation was obtained when it was deposited in pure Ar gas. For NiO film deposited in pure O$_2$ gas, on the other hand, the orientation of the film changed from (100) to (111) and its deposition rate decreased. The origin of the preferred orientation of the films was discussed. NiO films also showed different surface morphologies and roughnesses with the oxygen flow ratio.

• Proceedings of the Korea Contents Association Conference
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• 2009.05a
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• pp.807-809
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• 2009

Thin film deposition methods have been widely used and intensively investigated because high quality crystalline films enable to fabricate by sputtering. Especially rf magnetron sputtering deposition has advantages of being employ a relatively high deposition rate and also to achieve high crystalline films in low pressure because plasma density around target by magnetic is high. To apply ZnO thin film for SAW filter, it has highly flat surface, excellent c-axis preferred orientation and high resistivity value. As-deposited ZnO films showed the strong c-axis growth and excellent crystallinity. C-axis preferred orientation, resistivity and surface roughness highly depended on oxygen/argon gas ratio.

• Polymer(Korea)
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• v.28 no.1
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• pp.67-76
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• 2004

The effects of drawing temperature and draw down ratio on thermal properties, crystallinity and orientation of poly(trimethylene terephthalate)/poly(ethylene terephthalate) (PTT/PET) 100/0 ,90/10, and 80/20 blends have been investigated. The crystallinity and glass transition temperature increased while cold crystallization temperature and cold enthalpy decreased due to the development of orientation and stress induced crystallization by the cord drawing. Introducing PET to PTT decreased the crystallinity of PTT. However, it enhanced the orientation of PTT/PET blends drawn at below the glass transition temperature of PET. This lead to the increase of tensile modulus and tensile strength of PTT/PET blends. The shrinkage increased with increasing orientation, which might be minimized by the development of crystalline morphology of PTT in the course of cold drawing.

• Korean Journal of Materials Research
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• v.14 no.2
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• pp.121-125
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• 2004

Nickel oxide (NiO) thin films were deposited on Si(100) substrates at room temperature by RF magnetron sputtering from a NiO target. The effects of plasma gas and RF power on the crystallographic orientation and surface morphology of the NiO films were investigated. X-ray diffraction (XRD), field emission scanning electron microscopy (FE-SEM) and atomic force microscopy (AFM) were employed to characterize the deposited film. It was found that the type of plasma gases affected the crystallographic orientation, deposition rate, surface morphology, and crystallinity of NiO films. Highly crystalline NiO films with (100) orientation were obtained when it was deposited under Ar atmosphere. On the other hand, (l11)-oriented NiO films with poor crystallinity were deposited in $O_2$. Also, the increase in RF power resulted in not only higher deposition rate, larger grain size, and rougher surface but also higher crystallinity of NiO films.

• Journal of the Korean institute of surface engineering
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• v.17 no.2
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• pp.41-58
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• 1984

Zinc was electrodeposited from cyanide solutions at temperature from 20$^{\circ}C\;to\;40^{\circ}C$ in the range of current density from 0.5 to 8A/$dm^2$. The preferred orientation changed from (10.3)+(11.0) to (11.0) texture with increasing cathode overpotential in the additive free solution, while the (11.0) preferred orientation developed at lower overpotentials (800-1270 mV) and the (11.0)+(10.0) preferred orientation was formed at higher overpotential (1300-1400mV) in the solution with brightner. Mossy type of morphology developed mostly in the additive free deposits and the microstructure of the cross section of the above deposits changed from columar structure to granular structure with increasing overpotential. The surface appearance of the deposits with additive having (11.0) texture was the smooth deposit of very small crystallite, while that of the deposits having (11.0)+(10.0) texture was fine crystalline deposit. The microstructure of the cross section of them was the fine field oriented type of structure.