• Proceedings of the Korean Vacuum Society Conference
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• 2013.08a
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• pp.144.2-144.2
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• 2013

With the synthesis of graphene sheets as large-scale and high quality, it is essentially important to develop suitable graphene patterning process for future industrial applications. Especially, transfer or patterning method of CVD-grown graphene has been studied. We report simple soft lithographic process to develop easily applicable patterning method of large-scale graphene sheets by using chemically functionalized polymer stamp. Also important applications, the prototype capacitors with graphene electrode and commercial polymer dielectrics for the electrostatic-type touch panel are fabricated using the developed soft lithographic patterning and transfer process.

• Journal of the Korean Ceramic Society
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• v.39 no.8
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• pp.750-757
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• 2002

Self-patterning of thin films using photosensitive sol solution has advantages such as simple manufacturing process compared to photoresist/dry etching process. In this study, ferroelectric $Sr_{0.9}Bi_{2.1}Ta_2O_9$ thin films have been prepared by spin coating method using photosensitive sol solution. Strontium ethoxide, tertramethylheptanedionato bismuth and tantalum ethoxide were used as starting materials. As UV exposure time to the SBT thin film increased, the UV absorption peak intensity of metal ${\beta}$-diketonate decreased due to reduced solubility by M-O-M bond formation. Solubility difference by UV irradiation on SBT thin film allows to obtain a fine patterning of thin film. Also, The ferroelectric properties of the UV irradiated SBT thin films were superior to those of the no-UV irradiated films.

• 한국정보디스플레이학회:학술대회논문집
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• 2007.08a
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• pp.151-154
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• 2007

We demonstrate a novel selective patterning process of a semiconducting polymer for channel regions to fabricate an array of organic thin-film transistors (OTFTs). This process is applicable for various organic films over large area. A reflective liquid crystal display based on the OTFT array was produced using the selective patterning through a wettability control.

• Journal of the Korean Ceramic Society
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• v.40 no.2
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• pp.153-158
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• 2003

Self-patterning of thin films using photosensitive sol solution has advantages such as simple manufacturing process compared to photoresist/dry etching process. In this study,$La_{0.5}SR_{0.5}CoO_3$(LSCO) thin films as an electrode material for ferroelectric memories have been prepared by spin coating method using photosensitive sol solution. La-2methoxyethoxide, Sr-ethoxide, Co-2methoxyethoxide were used as starting materials. As UV exposure time to the LSCO gel thin film increased, the UV absorption peak intensity of metal${beta}$-diketonate decreased due to reduced solubility by M(metal)-O-M bond formation. Solubility difference by UV irradiation on LSCO gel thin film allows to obtain a fine patterning of thin film. The LSCO thin films annealed over$680{\circ}C$ in air showed perovskite phase and the lowest resistivity$(4{ imes}10^{-3}{Omega}cm)$ of the thin films were obtained by annealing at$740{\circ}C$.

• Laser Solutions
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• v.14 no.3
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• pp.1-6
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• 2011

Globally, the interest of renewable energy has become an upsurge. Especially, the solar industry is the one which is getting rapid growth rate. Many of researchers have been undertaking to improve the efficiency of solar cell to accomplish grid parity. The most of research has been concentrated on two methods, one on the selective emitter and the other is on LBSF (Local Back Surface Field) formation. Laser patterning will be needed to eliminate the thin film to form selective emitter and LBSF of solar cell. This paper reports some experimental results in laser patterning process for high-efficiency crystalline solar cell manufacturing. The experimental results indicate that the patterning quality depends on the average power and repetition rate of laser. The experimental results prove that the laser patterning process is an advantageous method to improve the efficiency of solar cell.

• Laser Solutions
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• v.12 no.4
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• pp.1-5
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• 2009

Conventional patterning based on wet-process for multi-layered film is a relatively complex and costly process though it is a necessary step for fabrication of TFT-LCD module. Recently, a direct pattering by laser has been studied because it is low cost and simple process compared to the wet process. In this work, the selective removal process of multi-layered film (polyimide/indium tin oxide/glass) is studied by modeling the thermal and mechanical behavior for multi-layered structure. Especially, the effects of thickness of polyimide layer are examined.

• 한국전산유체공학회:학술대회논문집
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• 2008.03b
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• pp.658-659
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• 2008

Numerical simulation is performed for a microdroplet deposition on the pre-patterned micro-structure. The liquid-air interface is tracked by level set method improved by incorporating the ghost fluid approach based on a sharp-interface representation. The method is further extended to treat the contact angle condition at an immersed solid surface. The present computation of a patterning process using microdroplet ejection demonstrates that the multiphase characteristics between the liquid-gas-solid phases can be used to overcome the patterning error.

• Korean Journal of Metals and Materials
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• v.48 no.2
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• pp.163-168
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• 2010

We here describe the laser-direct patterning of nanostructured metal thin films. This method involves light-matter interaction in which a pulsed laser beam impinging on the film generates a thermoelastic force that plays a role to detach the film from the substrate or underlying layers. A moderate cohesion of the nanostructured film enables localized desorption of the material upon irradiation by a spatiallymodulated laser beam, giving good fidelity with the transfered pattern. This photoresist-free process provides a simple high-resolution scheme for patterning metal thin films.

• Proceedings of the Korean Society for Technology of Plasticity Conference
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• 2005.09a
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• pp.54-58
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• 2005

Femtosecond laser is the latest generation pulsed laser delivering shortest pulses. Any solid materials can be machined by it. Femtosecond laser micromachining allows highest precision and minimal heat influence within the workpiece. But due to the complex physical phenomena between the laser beam and the workpiece materials, it is very difficult to determine the optimal process conditions in the femtosecond laser micromachining. In this study, a method to simulate the femtosecond laser micromachining process was proposed. And femtosecond laser micro patterning processes of chromium thin film are simulated by the proposed method using a commercial FE code, LS-Dyna. Simulation results were compared with those of experiments.

• Proceedings of the Korean Vacuum Society Conference
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• 2014.02a
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• pp.176.2-176.2
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• 2014

In this work, we demonstrated that the fabrication of flexible graphene-based chemical sensor with heaters by soft lithographic patterning method [1]. First, monolayer and multilayer graphene were prepared by thermal chemical vapor deposition transferred onto SiO2 / Si substrate in order to fabrication of patterned-sensor and -heater. Second, patterned-monolayer and multilayer graphene were detached through soft lithography process, which was transferred on top and bottom sides of PET film. Third, Au / Ti (Thickness : 100/30 nm) electrodes were deposited end of the patterned-graphene line by sputtering system. Finally, we measured sensor properties through injection of NO2 and CO2 gas on different temperature with voltage change of graphene heater.