• Proceedings of the Korean Vacuum Society Conference
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• 2014.02a
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• pp.211.1-211.1
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• 2014

Recently, the scaling of conventional planar NAND flash devices is facing its limits by decreasing numbers of electron stored in the floating gate and increasing difficulties in patterning. Three-dimensional vertical NAND devices have been proposed to overcome these issues. Atomic layer deposition (ALD) is the most promising method to deposit charge trap layer of vertical NAND devices, SiN, with excellent quality due to not only its self-limiting growth characteristics but also low process temperature. ALD of silicon nitride were studied using NH3 and silicon chloride precursors, such as SiCl4[1], SiH2Cl2[2], Si2Cl6[3], and Si3Cl8. However, the reaction mechanism of ALD silicon nitride process was rarely reported. In the present study, we used density functional theory (DFT) method to calculate the reaction of silicon chloride precursors with a silicon nitride surface. DFT is a quantum mechanical modeling method to investigate the electronic structure of many-body systems, in particular atoms, molecules, and the condensed phases. The bond dissociation energy of each precursor was calculated and compared with each other. The different reactivities of silicon chlorides precursors were discussed using the calculated results.

• Korean Journal of Materials Research
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• v.26 no.11
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• pp.635-643
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• 2016

Graphene has shown exceptional properties for high performance devices due to its high carrier mobility. Of particular interest is the potential use of graphene nanoribbons as field-effect transistors. Herein, we introduce a facile approach to the fabrication of graphene nanoribbon (GNR) arrays with ~200 nm width using nanoimprint lithography (NIL), which is a simple and robust method for patterning with high fidelity over a large area. To realize a 2D material-based device, we integrated the graphene nanoribbon arrays in field effect transistors (GNR-FETs) using conventional lithography and metallization on highly-doped $Si/SiO_2$ substrate. Consequently, we observed an enhancement of the performance of the GNR-transistors compared to that of the micro-ribbon graphene transistors. Besides this, using a transfer printing process on a flexible polymeric substrate, we demonstrated graphene-silicon junction structures that use CVD grown graphene as flexible electrodes for Si based transistors.

• Proceedings of the Korean Society for Technology of Plasticity Conference
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• 2004.10a
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• pp.40-43
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• 2004

Stamps for microcontact processing are fabricated by casting elastomer such as PDMS on a master with a negative of the desired pattern. After curing, the PDMS stamp is peeled away from the master and exposed to a solution of ink and then dried. Transfer of the ink from the PDMS stamp to the substrate occurs during a brief contact between stamp and substrate. Generally, negative-tone masters, which are used for making positive-tone PDMS stamps, are fabricated by using photolithographic technique. The shortcomings of photolithography are a relative high-cost process and require extensive processing time and heavy capital investment to build and maintain the fabrication facilities. The goal of this study is to fabricate a negative-tone master by using Nano-indenter based patterning technique. Various sizes of V-grooves and U-groove were fabricated by using the combination of nanoscratch and HF isotropic etching technique. An achieved negative-tone structure was used as a master in the PDMS replica molding process to fabricate a positive-tone PDMS stamp.

• Transactions of Materials Processing
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• v.18 no.3
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• pp.268-273
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• 2009

Ultraviolet nanoimprint lithography (UV-NIL), which is performed at a low pressure and at room temperature, is known as a low cost method for the fabrication of nano-scale patterns. In the patterning process, maintaining the uniformity of the residual layer is critical as the pattern transfer of features to the substrate must include the timed etch of the residual layer prior to the etching of the transfer layer. In pursuit of a thin and uniform residual layer thickness, the initial volume and the position of each droplet both need to be optimized. However, the monomer mixtures of resin had a tendency to evaporate. The evaporation rate depends on not only time, but also the initial volume of the monomer droplet. In order to decide the initial volume of each droplet, the accurate prediction of evaporation behavior is required. In this study, the theoretical model of the evaporation behavior of resin droplets was developed and compared with the available experimental data in the literature. It is confirmed that the evaporation rate of a droplet is not proportional to the area of its free surface, but to the length of its contact line. Finally, the parameter of the developed theoretical model was calculated by curve fitting to decide the initial volume of resin droplets.

• Journal of the Semiconductor & Display Technology
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• v.10 no.4
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• pp.53-59
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• 2011

Recently there have been considerable attentions on nanoimprint lithography (NIL) by the display device and semiconductor industry due to its potential abilities that enable cost-effective and high-throughput nanofabrication. Although one of the current major research trends of NIL is large-area patterning, the technical difficulties to keep the uniformity of the residual layer become severer as the imprinting area increases more and more. In this paper we focused on the deformation of the $2^{nd}$ generation TFT-LCD sized ($370{\times}470mm^2$) large-area soft mold in the UV imprinting process. A mold was fabricated with PDMS(Poly-dimethyl Siloxane) layered glass back plate(t0.5). Besides, the mold includes large surrounding wall type protrusions of 1.9 mm width and the via-hole(7 ${\mu}m$ diameter) patterend area. The large surrounding wall type protrusions cause the proximity effect which severely degrades the uniformity of residual layer in the via-hole patterend area. Therefore the deformation of the mold was calculated by finite element analysis to assess the effect of large surrounding wall type protrusions and the flexiblity of the mold. The deformation of soft mold was verified by the measurements qualitatively.

• Journal of Integrative Natural Science
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• v.4 no.4
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• pp.311-314
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• 2011

Application of self-assembled monolayers (SAMs) to the fabrication of organic thin film transistor has been recently reported very often since it can help to provide ohmic contact between films as well as to form simple and effective electrode pattern. Accordingly, quality of these ultra-thin films is becoming more imperative. In this study, in order to manufacture a high quality SAM pattern, a hydrophobic alkylsilane monolayer and a hydrophilic aminosilane monolayer were selectively coated on $SiO_2$ surface through the consecutive procedures of a micro-contact printing (${\mu}CP$) and dip-coating methods under extremely dry condition. On a SAM pattern cleaned with SC1 solution immediately after ${\mu}CP$, poly(3,4-ethylenedioxythiophene) (PEDOT) source and drain electrode array were very selectively and nicely vapour phase polymerized. On the other side, on a SC1-untreated SAM pattern, PEDOT array was very poorly polymerized. It strongly suggests that the SC1 cleaning process effectively removes unwanted contaminants on SAM pattern, thereby resulting in very selective growth of PEDOT electrode pattern.

• 한국정보디스플레이학회:학술대회논문집
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• 2009.10a
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• pp.843-845
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• 2009

A polymeric host for triplet emitters composed of N-alkylcarbazole and tetramethylbenzene units was successfully synthesized. Efficient energy transfer was observed between this polymeric host and green phosphorescent dyes. The device fabricated using 5 wt% green 1 in the polymeric host as the emitting layer showed the best performance. Thin films of this host-guest system, exhibiting clear stripe patterns could be prepared through the LITI process. The patterned films were then used to fabricate electrophosphorescent devices, which show performance characteristics similar to those of spin-coated devices. The new host material is a good candidate to be used in polymer-based full-color electrophosphorescent light-emitting displays.

• Journal of the Microelectronics and Packaging Society
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• v.6 no.4
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• pp.15-22
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• 1999

Generally, many equipments and a long lead time ale required to manufacture the build-up multilayer board through various processes such as etching, plating, drilling etc. Wet process is suitable for mass production, however it is not adequate for manufacturing prototype in developing stage. In this study, a silk screen printing technology is introduced to make a prototype build-up multilayer board. As for the material photo/thermal curable resin and conductive paste are used for forming dielectric and conductor. And conductive paste fills vias for interconnecting each layer, and also is used for circuit patterning by silk screen technology. Finally, the basic concept and the possibility of build-up multilayer board prototype is proposed and verified as a powerful approach, compared with the conventional processes.

• Journal of Korea Game Society
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• v.21 no.1
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• pp.139-148
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• 2021

In a game, the visual environment element is a means of expressing the intention of the developer, and is mediums that enable the player to gain to play experience of interaction. In this paper, the player's reaction to the visual environmental elements of the adventure game was patterned with a collection and analysis process by empirical experiments. The data collected through the experiment were about 10,000, and as a result of the analysis, 24 types of player reaction patterns were found in total. This can be used as a guideline for game space design by matching the properties of visual environment elements and the reactions against players occurring in the game play process to examine the play experience.

• Journal of the Korean institute of surface engineering
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• v.56 no.2
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• pp.115-124
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• 2023

Anodization is an electrochemical process that electrochemically converts a metal surface into an oxide layer, resulting in enhanced corrosion resistance, wear resistance, and improved aesthetic appearance. Local anodization, also known as selective anodization, is a modified process that enables specific regions or patterns on the metal surface to undergo anodization instead of the entire surface. Several methods have been attempted to produce oxide layers via localized anodic oxidation, such as using a mask or pre-patterned substrate. However, these methods are often intricate, time-consuming, and costly. Conversely, the direct writing or patterning approach is a more straightforward and efficient way to fabricate the oxide layers. This review paper intends to enhance our comprehension of local anodization and its potential applications in various fields, including the development of nanotechnologies. The application of anodization is promising in surface engineering, where the anodic oxide layer serves as a protective coating for metals or modifies the surface properties of materials. Furthermore, anodic oxidation can create micro- and nano-scale patterns on metal surfaces. Overall, the development of efficient and cost-effective anodic oxidation methods is essential for the advancement of various industries and technologies.