• Proceedings of the Korean Vacuum Society Conference
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• 2014.02a
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• pp.166.2-166.2
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• 2014

In this work, we demonstrated a facile and effective method for deposition of metal tetraphenylporphyrin (MTPP) thin film by a combined a thermal evaporation (TE) and atomic layer deposition (ALD). For the deposition of Zn-TPP thin film, Tetraphenylporphyrin (TPP) and diethyl zinc (DEZ) were used as organic and inorganic materials, respectively. Optimum conditions for the deposition of Zn-TPP thin film were established systematically: (1) the exposure time of DEZ as inorganic precursor and (2) the substrate temperature were adjusted, respectively. As a result, we verified that the surface reaction between organic semiconductor (TPP) and metal atom (Zn) was ALD process. In addition, we calculated activation energy by using Arrhenius equation for the substrate temperature versus area change rate of pyrrolic nitrogen. The surface and interface reactions between TPP with Zn were investigated by X-ray photoelectron spectroscopy, Raman spectroscopy, UV-vis spectroscopy, and scanning electron microscopy. These results show a facile and well-controllable fabrication technique for the metal-organic thin film for future electronic applications.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2003.06a
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• pp.219-222
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• 2003

Self-Assembled Monolayers(SAMs) by alkanethiol adsorption to thin metal film are widely being investigated for applications as coating layer for anti-stiction or friction reduction and in fabrication of micro structure of molecular and bio molecular. Recently, there have been many researches on micro patterning using the advantages of very thin thickness and etching resistance in selective etching of thin metal film of Self- Assembled Monolayers. In this report, we present the micromachining thin metal film by Mask-Less laser patterning of alknanethiolate Self-Assembled Monolayers.

• Proceedings of the Korean Vacuum Society Conference
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• 2014.02a
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• pp.303.2-303.2
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• 2014

The oxides of group IV transition metals such as titanium, zirconium, hafnium have many important current and future application, including protective coatings, sensors and dielectric layers in thin film electroluminescent (TFEL) devices. Recently, group IV transition metal oxide films have been intensively investigated as replacements for SiO2. Due to high permittivities (k~14-25) compared with SiO2 (k~3.9), large band-gaps, large band offsets and high thermodynamic stability on silicon. Herein, we report the synthesis of new group IV transition metal complexes as useful precursors to deposit their oxide thin films using chemical vapor deposition technique. The complexes were characterized by FT-IR, 1H NMR, 13C NMR and thermogravimetric analysis (TGA). Newly synthesised compounds show high volatility and thermal stability, so we are trying to deposit metal oxide thin films using the complexes by Atomic Layer Deposition (ALD).

• International Journal of Precision Engineering and Manufacturing
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• v.7 no.1
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• pp.13-17
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• 2006

Self-Assembled Monolayers (SAMs) formed by alkanethiol adsorption to thin metal film are widely being investigated for applications as coating layer for anti-stiction or friction reduction and in fabrication of micro structure of molecules and bio molecules. Recently, there have been many researches on micro patterning using the advantages of very thin thickness and etching resistance of Self-Assembled Monolayers in selective etching of thin metal film. In this report, we present the several machining method to form the nanoscale structure by Mask-Less laser patterning using alknanethiolate Self-Assembled Monolayers such as thin metal film etching and heterogeneous SAM structure formation.

• Journal of the Korean Society for Precision Engineering
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• v.21 no.12
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• pp.160-166
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• 2004

Self-Assembled Monolayers(SAMs) by alkanethiol adsorption to thin metal film are widely being investigated fer applications as coating layer for anti-stiction or friction reduction and in fabrication of micro structure of molecule and bio molecule. Recently, there have been many researches on micro patterning using the advantages of very thin thickness and etching resistance of Self-Assembled Monolayers in selective etching of thin metal film. In this report, we present the several machining method to form the nanoscale structure by Mask-Less laser patterning using alknanethiolate Self-Assembled Monolayers such as thin metal film etching and heterogeneous SAMs structure formation.

• Proceedings of the Korean Vacuum Society Conference
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• 2013.08a
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• pp.76.2-76.2
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• 2013

Advanced electronic application areas have strongly required new materials due to the continuous shrinking dimensions of their devices. Specially, the development and use of metal precursors for atomic layer deposition has been extensively focused on application to electronic devices. Thus the systematic design and synthesis of metal compounds with relevant chemical and physical properties, such as stability, volatility, and resistance to air and moisture are very important in the vacuum deposition fields. In many case, organic ligands for metal precursors are especially focused in the related research areas because the large scale synthesis of the metal complexes with excellent properties exclusively depends on the potential usefulness of the ligands. It is recommended for metal complexes to be in monomeric forms because mononuclear complexes generally show high vapor pressures comparing with their oligomeric structure such as dimer and trimer. Simple metal alkoxides complexes are involatile except several examples such as Ti(OiPr)4, Si(OEt)4, and Hf(OtBu)4. Thus the coordinated atom of alkoxide ligands should be crowded in its own environment with some substituents by prohibiting the coordinated atoms from bonding to another metal through oxygen-bridging configuration. Alkoxide ligands containing donor-functionalized group such as amino and alkoxy which can induce the increasing of the coordinative saturation of the metal complexes and the decreasing of the intermolecular interaction between or among the metal compounds. In this presentation, we will discuss the development of metal compounds which adopted donor-functionalized alkoxide ligands derived from their alcohols for electronic application. Some recent results on ALD using metal precursors such as tin, nickel, ruthenium, and tungsten developed in our group will be disclosed.

• Proceedings of the Materials Research Society of Korea Conference
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• 2011.10a
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• pp.19.2-19.2
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• 2011

The $(Sr_{0.75},\;La_{0.25})TiO_3$ (SLTO) ultra-thin films with various thicknesses have been grown on Ti-O terminated $SrTiO_3$(100) substrate using Laser-Molecular Beam Epitaxy (Laser MBE). By monitoring the in-situ specular spot intensity oscillation of reflection high energy electron diffraction (RHEED), we controlled the layer-by-layer film growth. The film structure and topography were verified by atomic force microscopy (AFM) and high resolution thin film x-ray diffraction by the synchrotron x-ray radiation. We have also investigated the electronic band structure using x-ray absorption spectroscopy (XAS). The ultra thin SLTO film exhibits thickness driven metal-insulator transition around 8 unit cell thickness when the film thickness progressively reduced to 2 unit cell. The SLTO thin films with an insulating character showed band splitting in Ti $L_3-L_2$ edge XAS spectrum which is attributed to Ti 3d band splitting. This narrow d band splitting could drive the metal-insulator transition along with Anderson Localization. In optical conductivity, we have found the spectral weight transfer from coherent part to incoherent part when the film thickness was reduced. This result indicates the possibility of enhanced electron correlation in ultra thin films.

• Polymer(Korea)
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• v.36 no.5
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• pp.599-605
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• 2012

The physicochemical properties such as surface hardness, solvent mechanical wear resistance, and resistance to scratch properties of poly(3,4-ethylenedioxythiophene) (PEDOT) thin film prepared by vapor phase polymerization (VPP) was effectively improved by post-treatment of various metal alkoxide sol solutions. Metal oxide layer derived from sol-gel process of metal alkoxide was generated on the PEDOT thin film layer by VPP, resulting in improving mechanical properties of the conductive thin films without any deterioration of their original surface resistance. Several kinds of silicone and titanium alkoxide derivatives with various functional groups were used as metal alkoxide sol sources. Among them, PEDOT-metal oxide composite thin film derived tetraethyl orthosilicate showed the best performance in the terms of surface resistance, transmittance, and various physicochemical properties. The effect of metal alkoxide content in washing solution, oxidant content and drying temperature have been investigated in order to optimize the various properties of PEDOT-metal oxide composite thin film.

• Journal of the Korean Vacuum Society
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• v.6 no.S1
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• pp.110-114
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• 1997

Development of metal ion source growth of high quality Cu metal film formation of non-stoichiometric $SnO_2$ films of Si(100), and modification fo polymer surface by low enregy ion beam have been carried out at KIST Ion Beam Lab. A new metal ion source with high ion beam flux has been developed by a hybrid ion beam (HIB) deposition and non-stoichiometric $SnO_2$ films are controlled by supplying energy. The ion assisted reaction (IAR) in which keV ion beam is irradiated in reactive gas environment has been deveolped for modifying the polymers and enhancing adhesion to other materials and advantages of the IAR have been reviewed.

• Bulletin of the Korean Chemical Society
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• v.26 no.5
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• pp.829-832
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• 2005