• Title/Summary/Keyword: Monolayer films

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A Study on Electrical Properties of Dendrimer (덴드리머의 전기적 특성 연구)

  • Choi, Yong-Sung;Song, Jin-Won;Lee, Woo-Ki;Lee, Kyung-Sup
    • Proceedings of the KIEE Conference
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    • 2006.07c
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    • pp.1330-1332
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    • 2006
  • In the Langmuir-Blodgett (LB) technique, a monolayer on the water surface is transferred onto a substrate, which is raised and dipped through the surface. From this, multilayers can be obtained in which constituent molecules are periodically arranged. The LB technique has attracted considerable interest in the fabrication of electrical and electronic devices. Many researchers have investigated the electrical properties of monolayer and multiplayer films. Dendrimers represent a new class of synthetic macromolecules characterized by a regularly branched treelike structure. Multiple branching yields a large number of chain ends that distinguish dendrimers from conventional star-like polymers and microgels. The agobenzene dendrimer is one of the dendritic macromolecules that include the azo-group exhibiting a photochromic character. Due to the Presence of the charge transfer element of the azo-group and its rod-shaped structure, these compounds are expected to have potential interest in electronics and ptoelectronics, especially in nonlinear optics. In the present paper, we give pressure stimulation to organic thin films and detect the induced displacement current.

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Displacement Current Characteristics of Nano-Structural Dendrimer (나노구조 덴드리머의 변위전류 특성)

  • Song, Jin-Won;Choi, Yong-Sung;Lee, Kyung-Sup
    • Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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    • 2006.06a
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    • pp.358-359
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    • 2006
  • In the Langmuir-Blodgett (LB) technique, a monolayer on the water surface is transferred onto a substrate, which is raised and dipped through the surface. From this, multilayers can be obtained in which constituent molecules are periodically arranged. The LB technique has attracted considerable interest in the fabrication of electrical and electronic devices. Many researchers have investigated the electrical properties of monolayer and multiplayer films. Dendrimers represent a new class of synthetic macromolecules characterized by a regularly branched treelike structure. Multiple branching yields a large number of chain ends that distinguish dendrimers from conventional star-like polymers and microgels. The azobenzene dendrimer is one of the dendritic macromolecules that include the azo-group exhibiting a photochromic character. Due to the presence of the charge transfer element of the azo-group and its rod-shaped structure, these compounds are expected to have potential interest in electronics and ptoelectronics, especially in nonlinear optics. In the present paper, we give pressure stimulation to organic thin films and detect the induced displacement current.

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Langmuir-Blodgett Films of Perfluoroalkyl Monomaleate Copolymers on Porous Substrate

  • Hyein Jeong;Burm-Jong Lee;Young-Soo Kwon
    • Bulletin of the Korean Chemical Society
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    • v.15 no.8
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    • pp.650-654
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    • 1994
  • Stable polyion-complexed polymeric monolayers were prepared by spreading perfluoroalkyl monomaleate copolymers, $C_2F_8MA-VE_2$ and $C_2F_8MA-VE_3$, on a aqueous poly(allylamine) subphase. The monolayer properties have been studied by the surface pressure-area (${\pi}$-A) isotherms. The $C_2F_8MA-VE_3$ containing longer oligoethyleneglycol pendant showed more expanded monolayer phase than the $C_2F_8MA-VE_2$. The polyion-complexed monolayers were transferable on various substrates, and the resulting Langmuir-Blodgett (LB) films were characterized by FT-IR spectroscopy and scanning electron microscopy (SEM). Two-dimensional crosslinking to form a polymer network was achieved by amide formation through heat treatment under vacuum with concurrent removal of perfluoroalkyl tails. SEM observation of this film on a porous membrane filter showed that the four layer film was sufficiently stable to cover the filter pore size of 0.1 ${\mu}$m. The $C_2F_8MA-VE_3$ revealed better covering capability than the $C_2F_8MA-VE_2$. Immersion of this film in water or in benzene did not cause any change in its appearance and in Fl-IR spectra.

Effect of HF and Plasma Treated Glass Surface on Vapor Phase-Polymerized Poly(3,4-ethylenedioxythiophene) Thin Film : Part II

  • Lee, Joonwoo;Kim, Sungsoo
    • Journal of Integrative Natural Science
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    • v.6 no.4
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    • pp.215-219
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    • 2013
  • In this study, in order to investigate how consecutive treatments of glass surface with HF acid and water vapor/Ar plasma affect the quality of 3-aminopropyltriethoxysilane self-assembled monolayer (APS-SAM), poly(3,4-ethylenedioxythiophene) (PEDOT) thin films were vapor phase-polymerized immediately after spin coating of FeCl3 and poly-urethane diol-mixed oxidant solution on the monolayer surfaces prepared at various treatment conditions. For the film characterization, various poweful tools were used, e.g., FE-SEM, an optical microscope, four point probe, and a contact angle analyzer. The characterization revealed that a well prepared APS-SAM on a glass surface treated with water vapor/Ar plasma is very useful for uniform coating of FeCl3 and DUDO mixed oxidant solution, regardless of HF treatment. On the other hand, a bare glass surface without APS-SAM but treated with HF and water vapor/Ar plasma generally led to a very poor oxidant film. As a result, PEDOT films vapor phase-polymerized on APS-SAM surfaces are far superior to those on bare glass surfaces in the quality and electrical characteristics aspects.

ALD of Nanometal Films and Applications for Nanoscale Devices

  • Kim, Hyung-Jun
    • Korean Journal of Crystallography
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    • v.16 no.2
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    • pp.89-101
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    • 2005
  • Among many material processing related issues for successful scaling down of devices for the next 10 years or so, the advanced gate stack and interconnect technology are two most critical research areas, which need technical innovation. The introduction of new metallic films and appropriate processing technologies are required more than ever. Especially, as the device downscaling continues well into sub 50 nm regime, the paradigm for metal nano film deposition technique research has been shifted to high conformality, low growth temperature, high quality with uniformity at large area wafers. Regarding these, ALD has sparked a lot of interests for a number of reasons. The process is intrinsically atomic in nature, resulting in the controlled deposition of films in sub-monolayer units with excellent conformality. In this paper, the overview on the current issues and the future trends in device processing technologies related to metal nano films as well as the R&D trends in these applications will be discussed. The focus will be on the applications for metal gate, capacitor electrode for DRAM, and diffusion barriers/seed layers for Cu interconnect technology.

A Comparison to Electrical properties of Fatty Acid System LB Films in Horizontal Direction (포화지방산계 LB막의 수평방향에 대한 전기적 특성 비교)

  • 김도균;최용성;장정수;권영수
    • Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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    • 1997.04a
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    • pp.194-197
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    • 1997
  • The LB technique is one of the most powerful fabricating methods of organic ultra-thin film, which deposits a monolayer films in molecular level on the surface of the substrate. We have investigated the electrical characteristics of Myristic acid, Stearic acid and Arachidic acid LB films for horizontal direction to develop for the gas sensor. The optimum conditions for a film deposition were obtained by measurement of $\pi$-A isotherm. The status of the deposited film was confirmed by measurement of UV absorbance. We could distingished the difference of I-V characteristics for the fatty acid for the horizontal direction. The conductivity of fatty acid LB films for horizontal direction was 10$^{-7}$ ~ 10$^{-9}$ [S/cm] that mean like semiconductor.

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Electrical Properties and Surface Morphology for Temperature in PU Derivatives Monolayers (PU 유도체 단분자막의 온도에 따른 전기 물성과 표면 형상 관찰)

  • Seo, Jeong-Yeul;Kim, Do-Kyun;Park, Jae-Chul;Kwon, Young-Soo
    • Proceedings of the KIEE Conference
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    • 2000.11c
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    • pp.458-460
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    • 2000
  • We attempted to fabricate polyurethane derivatives (PU-CN, PU-DCM) LB films by using LB method. Also, we investigated the monolayer behavior at the air-water interface by surface pressure-area ($\pi$-A) isotherms. And, the surface morphologies and the physicochemical properties of LB films were investigated by atomic force microscopy (AFM) and UV-vis spectroscopy, respectively. Also, the electrical properties of polyurethane derivatives LB films were investigated by using the conductivity, the dielectric constant and activation energy. In the surface morphologies, physicochemical, electrical properties of polyurethane derivatives LB films, the properties is different as to the Polyurethane derivatives, it is considered that this phenomena could be described by the difference of lumophore pendant which was adhered at PU main chain.

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Deposition Transfer and Response Properties of p-PDA/AA Mixed Films (p-PDA/AA 혼합막의 누적전이와 응답특성)

  • 송진원;이경섭
    • Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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    • 2000.07a
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    • pp.511-514
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    • 2000
  • Photoreactive multilayer films were prepared using long-chin alkyl diesters of p-phenylenediacrylic acid(p-PDA). In spite of the absence of hydrophilic groups in these molecules, they formed stable monolayers on the water surface when mixed with arachidic acid. Surface showed the presence of a condecsed phase and these monolayer could be transferred onto a substrate with Y-type deposition. The UV spectra of mixed multilayer films showed of absorption peak compared with that in solution. The linear relationship between absorbanoe and the number of layers supports the successful formation of multilayer films.

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Deposotion Characteristics of Maleate LB Films (말레에이트계 LB막의 누적특성)

  • 신훈규;최용성;김은구;김경철;권영수
    • Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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    • 1994.05a
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    • pp.99-102
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    • 1994
  • The use of preformed polymers and their cross-linking have been a attempted in order to improve the intrinsic fraqility of monolayers and Langmuir-Blodgett (LB)films and to make their technological applications possible. It has shown that an imidization followed a polyion-complexation can stabilize the LB films against heat and solvents. And when the polymer structure was properly designed concurrent removal of the alkyl tails together with imide formation could be accomplished. In this paper we present a characteristic monolayer behavior of polymer with pendent polythers and carboxyls it’s polyion-complexed LB film with subphase polymer PAA and a possible skeletonization of the LB film by thermal imidization. Also deposition status of LB films are evaluated by using QCM

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A study on Electrical Properties of the Polyamic Acid Alkylamine Salts(PAAS) LB films (Polyamic Acid Alkylamine Salts(PAAS) LB 박막의 전기적 특성에 관한 연구)

  • 이호식;이원재;김태완;강도열
    • Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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    • 1997.11a
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    • pp.298-301
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    • 1997
  • This paper describes the thermally stimulated current(TSC) measurements arachidic acid(AA) and polyamic acid alkylamine salts(PAAS) LB film, which is a precursor of polyimide(PI). The measurements were performed from room temperature to about 250$^{\circ}C$ and the temperature was increased at a rate of 0.02 $^{\circ}C$/s linearly[4]. It shows that peaks of TSC are observed at about 80$^{\circ}C$ in the arachidic acid and about 80$^{\circ}C$, 160$^{\circ}C$ in the PAAS LB films. The DSC and TGA of PAAS, arachidic acid are measure. Monolayer phases on the water subphase such as Langmuir(L) films and the phase transitions from gas phase to solid phase via liquid phase are observed using Brewster angle microscopy(BAM). BAM is also used to observe the Langemuir-Blodgett(LB) films.

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