• Electrical & Electronic Materials
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• v.8 no.6
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• pp.795-805
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• 1995

A novel thin film processing technique has been developed for the fabrication of ultrathin films of conducting polymers with molecular-level control over thickness and multilayer architecture. This new self-assembly process opens up vast possibilities in applications which require large area, ultrathin films of conducting polymers and more importantly in applications that can take advantage of the unique interactions achievable in the complex, supermolecular architectures of multilayer films.

• The Transactions of the Korean Institute of Electrical Engineers
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• v.41 no.7
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• pp.753-759
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• 1992

For the fabrication of the microscale memory or electrical devices, Langmuir-Blodgett(LB) method is the most possible candidate. N-Alkylquinolium-TCNQ compounds were synthesized. The structure of the compounds were identified by the NMR spectroscopy and the purity were checked to be good by the elemental analysis. The surface pressure($\pi$) was measured at the air-water interface. The isotherm showed two transitions at 30mN/m and 45mN/m. The LB films were deposited by the home-made Kuhn type apparatus. The transfer ratio($\tau$) of the deposition was more than 0.95 for the up-stroke and less than 0.4 for the down-stroke. The absorbance peaks of the LB films appear at around 420nm and 700-820nm.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2010.03b
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• pp.20-20
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• 2010

We present a simple process for the fabrication of high performance transparent conducting films that contain single-walled carbon nanotubes (SWCNTs) noncovalently coated with an ultrathin titania layer. The hydrophobic interactions between nanotube surfaces and the acetylacetone (acac) ligands used to stabilize the $TiO_2$ precursor provide an interesting alternative method for noncovalently coating the SWCNTs with a titania layer. The ultrathin titania layer on SWCNTs prevented the oxidation of functionalized SWCNTs at high temperatures, and protected against water molecule absorption.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2010.06a
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• pp.279-279
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• 2010

We present a simple process for the fabrication of high performance transparent conducting films that contain single-walled carbon nanotubes (SWCNTs) noncovalently coated with an ultrathin titania layer. The hydrophobic interactions between nanotube surfaces and the acetylacetone (acac) ligands used to stabilize the $TiO_2$ precursor provide an interesting alternative method for noncovalently coating the SWCNTs with a titania layer. The ultrathin titania layer on SWCNTs prevented the oxidation of functionalized SWCNTs at high temperatures, and protected against water molecule absorption.

• Electronics and Telecommunications Trends
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• v.3 no.4
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• pp.3-12
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• 1988

Epilayer growing process has been recognized as a key technology for successful GaAs based devices and integrations. These may include HEMT, multiple quantum well structures, band gap engineering, and quantum confinement heterostructures. The fabrication of epilayers in these devices must meet very stringent requirements in terms of crystallinity, composition, film thickness and interface quality. In particular, the quality of interfaces is getting more important because the film thickness, and flatness, roughness and stability at interface of ultrathin films cause critical effects on the device performance. This article reviews the current status of modern epitaxial techniques which have been developed in the last few years. First, the new techniques PLE, GI, MEE, TSL based on MBE technique will be reviewed and their technical importance will be stressed. Secondly, MOMBE, GSMBE, CBE which combine the advantages of MBE and MOCVD will also be discussed. Thirdly, the new sophisticated epitaxial technique, ALE, of which mechanism is totally different from others, will also be reviewed. Finally, areas which should be exploited more extensively to accomplish these techniques will be addressed.

• Proceedings of the Korean Vacuum Society Conference
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• 2012.02a
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• pp.549-549
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• 2012

Early detection of cancer biomarkers in the blood is of vital importance for reducing the mortality and morbidity in a number of cancers. From this point of view, immunosensors based on nanowire (NW) and carbon nanotube (CNT) field-effect transistors (FETs) that allow the ultra-sensitive, highly specific, and label-free electrical detection of biomarkers received much attention. Nevertheless 1D nano-FET biosensors showed high performance, several challenges remain to be resolved for the uncomplicated, reproducible, low-cost and high-throughput nanofabrication. Recently, two-dimensional (2D) graphene and reduced GO (RGO) nanosheets or films find widespread applications such as clean energy storage and conversion devices, optical detector, field-effect transistors, electromechanical resonators, and chemical & biological sensors. In particular, the graphene- and RGO-FETs devices are very promising for sensing applications because of advantages including large detection area, low noise level in solution, ease of fabrication, and the high sensitivity to ions and biomolecules comparable to 1D nano-FETs. Even though a limited number of biosensor applications including chemical vapor deposition (CVD) grown graphene film for DNA detection, single-layer graphene for protein detection and single-layer graphene or solution-processed RGO film for cell monitoring have been reported, development of facile fabrication methods and full understanding of sensing mechanism are still lacking. Furthermore, there have been no reports on demonstration of ultrasensitive electrical detection of a cancer biomarker using the graphene- or RGO-FET. Here we describe scalable and facile fabrication of reduced graphene oxide FET (RGO-FET) with the capability of label-free, ultrasensitive electrical detection of a cancer biomarker, prostate specific antigen/${\alpha}$ 1-antichymotrypsin (PSA-ACT) complex, in which the ultrathin RGO channel was formed by a uniform self-assembly of two-dimensional RGO nanosheets, and also we will discuss about the immunosensing mechanism.

• Proceedings of the Polymer Society of Korea Conference
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• 2006.10a
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• pp.237-237
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• 2006

P(VDF/TrFE(72/28) ultrathin films were used in the fabrication of Metal-Ferroelectric polymer-Metal (MFM) single bit device with special emphasis on uniform film surface, faster dipole switching time under applied external field and longer memory retention time. AFM and FTIR-GIRAS were complementary in analyzing surface crystalline morphology and the resultant change in chain orientation with varying thermal history. DC-EFM technique was used to 'write-read-erase' the data on the memory bit in a much faster time than P-E studies. The results obtained from this study will enable us to have a good understanding of the ferroelectric and piezoelectric behavior of P(VDF/TrFE)(72/28) thin films suitable for high density data storage applications.

• Proceedings of the KIEE Conference
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• 1993.11a
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• pp.174-177
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• 1993

The polyimide films were prepared by imidizing the polyamic acid long-chain alkylamine (dimethylhexadecylamine) salt films with a thermal and chemical treatment, where the polyamic acid alkylamine salt film were formed on various substrates by using Langmuir-Blodgett (LB) method. The imidization of polyamic acid alkylamine salt films with various thickness were identified with FT-IR and UV-visible absorption spectroscopies. Atomic Force Microscopy (AFM) have been used to investigate the surface morpology of polyamic acid alkylamine salt and imidized films.

• Journal of the Korean Magnetics Society
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• v.8 no.2
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• pp.99-110
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• 1998

MR head technology from the perspective of read sensor evolution was reviewed. AMR sensors have been developed for last two decades and successfully employed into information storage devices such as disk drives. Development of manufacturable GMR sensors is of emerging technological interest because GMR sensors can further meet the need of ultrahigh recording density. In this review, the mechanisms, materials systems, operating principles of both AMR an GMR sensors, and the head structures were discuseed. Constructing GMR heads with ultrathin sensor materials and complex topographical structures demands unique fabrication and design challenges. The commercialization of GMR heads can only be realized by the succesful implementations of high performance materials, advanced thin film processes, and stable head design.

• Proceedings of the Korean Vacuum Society Conference
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• 2010.02a
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• pp.9-10
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• 2010

Since the discovery of graphene by mechanical exfoliation from graphite[1], various fabrication methods are available today such as chemical exfoliation, epitaxial graphene on SiC substrates, etc. In view of industrialization, the mechanical exfoliation method may not be an option. Epitaxial graphene on SiC substrates, in this respect, is by far more practical because the method consists of conventional thermal treatments familiar to semiconductor industry. Still, the use of the SiC substrate itself, and hence the incompatibility with the Si technology, lessens the importance of this technology in its future industrialization. In this context, we have tackled the problem of forming graphene on Si substrates (GOS). Our strategy is to form an ultrathin (~80 nm) SiC layer on top of a Si substrate, and to graphitize the top SiC layers by a vacuum annealing. We have actually succeeded in forming the GOS structure [2,3,4]. Raman-scattering microscopy indicates presence of few-layer graphene (FLG) formed on our annealed SiC/Si heterostructure, with the G ($1580\;cm^{-1}$) and the G'($2700\;cm^{-1}$) bands, both related to ideal graphene, clearly observed. Presence of the D ($1350\;cm^{-1}$) band indicates presence of defects in our GOS films, whose elimination remains as a challenge in the future. To obtain qualified graphene films on Si substrate, formation of qualified SiC films is crucial in the first place, and is achieved by tuning the growth parameters into a process window[5]. With a potential for forming graphene films on large-scale Si wafers, GOS is a powerful candidate as a key technology in bringing graphene into silicon technology.