• Journal of the Korean Vacuum Society
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• v.7 no.1
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• pp.17-23
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• 1998

$Pb(Fe_{0.5}Nb_{0.5}O_3(PFN)$ thin films were prepared by rf magnetron co-sputtering method on $SiO_2/Si$, ITO/glass, and $Pt/Ti/SiO_2/Si$ substrates and post-annealed at the $N_2$ atmosphere by RTA(rapid thermal annerling). The degree of crystallinity of PFN films was identified on various substrates. Electrical properties of PFN films was characterized for $Pt/PFN/Pt/Ti/SiO_2/Si$ structure. The composition of PFN films was estimated by EPMA (electron probe micro analysis). PFN films would be crystallized better to perovskite phase on ITO/glass substrate than $SiO_2/Si$ substrate. This may be induced by the deformation of Pb deficient pyrochlore phase due to Pb diffusion into $SiO_2/Si$ substrate. PFN films on $Pt/Ti/SiO_2/Si$ substrate. PFN films with 5-10% Pb excess were crystallized to perovskite phase from $500^{\circ}C$ temperature. In summary, we show that Pb composition and annealing temperature were critically influenced on crystallinity to perovskite phase. When PFN film with 17% Pb excess was annealed at $600^{\circ}C$ at the $N_2$ atmosphere for 300kV/cm and 88. Its remnant polarization coercive field $2.0 MC/cm^2$ and 144kV/cm, respectively.

• Current Photovoltaic Research
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• v.2 no.4
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• pp.173-176
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• 2014

We have investigated the seed layer formation of front side contact using the inkjet printing process. Conductive silver ink was printed on textured Si wafers with 80 nm thick $SiN_x$ anti reflection coating (ARC) layers and thickened by light induced plating (LIP). The inkjet printable sliver inks were specifically formulated for inkjet printing on these substrates. Also, a novel method to prepare nano-sized glass frits by the sol-gel process with particle sizes around 5 nm is presented. Furthermore, dispersion stability of the formulated ink was measured using a Turbiscan. By implementing these glass frits, it was found that a continuous and uniform seed layer with a line width of $40{\mu}m$ could be formed by a inkjet printing process. We also investigated the contact resistance between the front contact and emitter using the transfer length model (TLM). On an emitter with the sheet resistance of $60{\Omega}/sq$, a specific contact resistance (${\rho}_c$) below $10m{\Omega}{\cdot}cm^2$ could be achieved at a peak firing temperature around $700^{\circ}C$. In addition, the correlation between the contact resistance and interface microstructures were studied using scanning electron microscopy (SEM). We found that the added glass particles act as a very effective fire through agent, and Ag crystallites are formed along the interface glass layer.

• Korean Chemical Engineering Research
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• v.58 no.3
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• pp.474-479
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• 2020

The etching solution for slimming of glass substrates was manufactured and HF was used as the main ingredient of wet etching solutions. Various types of strong acids such as HCl, HNO₃, H₂SO₄, amino acids and carboxylic acids such as citric acid, and etched solutions, respectively, were used to measure the etching rates and changes in surface shape of the glass. Regardless of the type of strong acids, the etching rate of the glass increased linearly as the added amount increased, and the sludge removal effect of the glass surface was also shown. The etching solution containing HCl showed more efficient results than other strong acids in the etching rate and the effect of removing sludge. The addition of carboxylic acid did not significantly affect the variation of etching rate, but had the effect of removing sludge. However, if amino acids were added, changes in etching rate and sludge removal were not significant.

• Journal of the Korean Ceramic Society
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• v.37 no.6
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• pp.604-611
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• 2000

Glass-ceramics containing a cordierite (2MgO-2Al2O3-5SiO2) as a main crystal phase was prepared from MgO-Al2O3-SiO2 system glass through a controlled 2-step heat treatment for the application to magnetic memory disk substrate for higher storage capacity. Parent glasses prepared with addition of CeO2 as a fulx and TiO2 as a nucleating agent were crystallized by a 2-step heat treatment i.e. nucleation and crystal grwoth. Then the maximum nucleation and crystal growth rates were investigated and several properties such as bending strength, surface hardness and surface roughness were also studied for heat treated glass. As a result, only a $\alpha$-cordierite was precipitated as a main crystal phase for all heat treatment conditions and the maximum nucleation and crystal growth rates were 2.4$\times$109/㎣.hr at 80$0^{\circ}C$ and 0.3${\mu}{\textrm}{m}$/hr at 915$^{\circ}C$ respectively. After being nucleated at 80$0^{\circ}C$ for 5 hours and then crystallized at 915$^{\circ}C$ for 1 hour, the heat treated glass had a crystal volume fraction of 17.6% and crystal size fo 0.3${\mu}{\textrm}{m}$, and showed the optimum properties for the application to magnetic memory disk substrates as follows. ; Bending strength of 192 MPa, Vidkers hardness of 642.1kgf/$\textrm{mm}^2$, and surface roughness of 27$\AA$.

• Proceedings of the Korean Institute of Surface Engineering Conference
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• 2001.11a
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• pp.68-68
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• 2001

Thin films of polycrystalline silicon (poly-Si) is a promising material for use in large-area electronic devices. Especially, the poly-Si can be used in high resolution and integrated active-matrix liquid-crystal displays (AMLCDs) and active matrix organic light-emitting diodes (AMOLEDs) because of its high mobility compared to hydrogenated _amorphous silicon (a-Si:H). A number of techniques have been proposed during the past several years to achieve poly-Si on large-area glass substrate. However, the conventional method for fabrication of poly-Si could not apply for glass instead of wafer or quartz substrate. Because the conventional method, low pressure chemical vapor deposition (LPCVD) has a high deposition temperature ($600^{\circ}C-1000^{\circ}C$) and solid phase crystallization (SPC) has a high annealing temperature ($600^{\circ}C-700^{\circ}C$). And also these are required time-consuming processes, which are too long to prevent the thermal damage of corning glass such as bending and fracture. The deposition of silicon thin films on low-cost foreign substrates has recently become a major objective in the search for processes having energy consumption and reaching a better cost evaluation. Hence, combining inexpensive deposition techniques with the growth of crystalline silicon seems to be a straightforward way of ensuring reduced production costs of large-area electronic devices. We have deposited crystalline poly-Si thin films on soda -lime glass and SiOz glass substrate as deposited by PVD at low substrate temperature using high power, magnetron sputtering method. The epitaxial orientation, microstructual characteristics and surface properties of the films were analyzed by TEM, XRD, and AFM. For the electrical characterization of these films, its properties were obtained from the Hall effect measurement by the Van der Pauw measurement.

• The Transactions of the Korean Institute of Electrical Engineers C
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• v.49 no.3
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• pp.149-154
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• 2000

Bi-layer Mo films were deposited on soda-lime glass substrates using DC magnetron supttering. Increasing gas pressure, the resistivity varied from $1\times10^{-5}\; to\; 8.3\times10^{-3}\; \Omega.cm$. Furthermore, stress direction yielded compressive-to-tensile transition stress curves. The micro-structure of the compressively-stressed film which had poor adhesion consists of tightly packed columns, but of the tensile-stressed films had less dense structure. Under all gas pressure conditions, Mo films exhibited distinctly increasing optical reflection with decreasing gas pressure. The expansion of (110) peak width with the gas pressure meant the worse crystalline growth. The impurity levels in the Mo film exhibited highly concentrated Na, Se and O elements due to less dense micro-structure. The degree of Na diffusion depends on the type of the glass substrate used and the nature of the Mo film.

• Journal of the Korean Institute of Telematics and Electronics
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• v.21 no.3
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• pp.39-45
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• 1984

Submicron gratings are fabricated holographically on thin film single mode and multimode waveguides. Thin film waveguides are made by spin-coating polyurethane solution on the substrates of microscope slide glass and Corning 7059 glass. In order to characterize thin film waveguides, the refract사e index and the thickness of thin films are measured by using the m-line spectroscopy. The fabricated gratings are tested as a grating coupler, a mode converter, and a beam splitter. Also chirped gratings are fabricated to observe beam expansion phenomena and thus the possibility of the wavelength demultiplexing.

• Proceedings of the Korean Vacuum Society Conference
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• 2015.08a
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• pp.178.1-178.1
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• 2015

In and Ga doped ZnO (IGZO) thin films were prepared by radio frequency magnetron sputtering without intentional substrate heating on glass substrate and TiO2-deposited glass substrates to consider the effect of a thin TiO2 buffer layer on the optical and electrical properties of the films. The thicknesses of the TiO2 buffer layer and IGZO films were kept constant at 5 and 100 nm, respectively. Since the IGZO/TiO2 bi-layered films show the higher FOM value than that of the IGZO single layer films, it is supposed that the IGZO/TiO2 bi-layered films will likely perform better in TCO applications than IGZO single layer films.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.26 no.6
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• pp.429-433
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• 2013

PTFE composites for use of microwave substrate were fabricated by impregnation and heat treatment fabrication with glass fabric. This study shows dielectric properties such as dielectric constant and loss can be controlled by thickness of PTFE composite with change of pressure condition in heating press process. The dielectric constant of the PTFE composites has decreasing tendency as given higher pressure condition. The dielectric loss has similar result too. Especially, the case of the dielectric loss was affected by the condition of pressure at heating press and had the best performance under 3 MPa. In order to see the reason why thickness conditions make different, their microstructures were also observed.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.66 no.8
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• pp.1236-1241
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• 2017

We deposited Al-doped ZnO (ZnO:Al) thin films on glass substrates ($200mm{\times}200mm$) by using in-line magnetron sputtering system. Effects of various deposition parameters such as working pressure, deposition power and substrate temperature on optoelectronic characteristics including surface-texture etching profiles were carefully investigated in this study. We found that relatively low working pressure and high deposition power offered to obtain enhanced conductivity and optical transmittance. Haze properties showed similar trend with the transmittance. Furthermore, surface-texture etching study exhibited good morphologies when the films were deposited at $200-300^{\circ}C$. On the basis of these optimizations, we could find the deposition region that produces highly transparent and conductive properties including efficient light scattering capability.