• Journal of the Korean Institute of Telematics and Electronics
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• v.26 no.7
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• pp.83-89
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• 1989

Ferroelectric $PbTiO_3$ thin film is deposited with rf sputtering at substrate temperature of $100-150^{\circ}C$. It is found that this has pyrochlore structure of amorphous type by X-ray diffractive analysis. Thermal annealing has excellent characteristics at $550^{\circ}C$ and laser annealing has best crystalline structure in case of scanning with 50 watts. Interface states in MFST and MFOST structure with a $PbTiO_3$ ferroelectric thin film gate have been investigated from analysis of C-V data. The interface states density has been drastically reduced by inserting an oxide layer between ferroelectric and semiconductor. The observed effect increase feasibility of employing ferroelectric thin films such as nonvolatile memory field effect transistor, IR optical FET, and Image Devices with a ferroelectric layer.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2008.06a
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• pp.477-477
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• 2008

For more than three decades, the gate dielectrics in CMOS devices are $SiO_2$ because of its blocking properties of current in insulated gate FET channels. As the dimensions of feature size have been scaled down (width and the thickness is reduced down to 50 urn and 2 urn or less), gate leakage current is increased and reliability of $SiO_2$ is reduced. Many metal oxides such as $TiO_2$, $Ta_2O_4$, $SrTiO_3$, $Al_2O_3$, $HfO_2$ and $ZrO_2$ have been challenged for memory devices. These materials posses relatively high dielectric constant, but $HfO_2$ and $Al_2O_3$ did not provide sufficient advantages over $SiO_2$ or $Si_3N_4$ because of reaction with Si substrate. Recently, $HfO_2$ have been attracted attention because Hf forms the most stable oxide with the highest heat of formation. In addition, Hf can reduce the native oxide layer by creating $HfO_2$. However, new gate oxide candidates must satisfy a standard CMOS process. In order to fabricate high density memories with small feature size, the plasma etch process should be developed by well understanding and optimizing plasma behaviors. Therefore, it is necessary that the etch behavior of $HfO_2$ and plasma parameters are systematically investigated as functions of process parameters including gas mixing ratio, rf power, pressure and temperature to determine the mechanism of plasma induced damage. However, there is few studies on the the etch mechanism and the surface reactions in $BCl_3$ based plasma to etch $HfO_2$ thin films. In this work, the samples of $HfO_2$ were prepared on Si wafer with using atomic layer deposition. In our previous work, the maximum etch rate of $BCl_3$/Ar were obtained 20% $BCl_3$/ 80% Ar. Over 20% $BCl_3$ addition, the etch rate of $HfO_2$ decreased. The etching rate of $HfO_2$ and selectivity of $HfO_2$ to Si were investigated with using in inductively coupled plasma etching system (ICP) and $BCl_3/Cl_2$/Ar plasma. The change of volume densities of radical and atoms were monitored with using optical emission spectroscopy analysis (OES). The variations of components of etched surfaces for $HfO_2$ was investigated with using x-ray photo electron spectroscopy (XPS). In order to investigate the accumulation of etch by products during etch process, the exposed surface of $HfO_2$ in $BCl_3/Cl_2$/Ar plasma was compared with surface of as-doped $HfO_2$ and all the surfaces of samples were examined with field emission scanning electron microscopy and atomic force microscope (AFM).

• Applied Microscopy
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• v.38 no.4
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• pp.279-284
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• 2008

The phase change materials have been extensively used as an optical rewritable data storage media utilizing their phase change properties. Recently, the phase change materials have been spotlighted for the application of non-volatile memory device, such as the phase change random access memory. In this work, we have investigated the crystallization behavior and microstructure analysis of In-Sb-Te (IST) thin films deposited by RF magnetron sputtering. Transmission electron microscopy measurement was carried out after the annealing at $300^{\circ}C$, $350^{\circ}C$, $400^{\circ}C$ and $450^{\circ}C$ for 5 min. It was observed that InSb phases change into $In_3SbTe_2$ phases and InTe phases as the temperature increases. It was found that the thickness of thin films was decreased and the grain size was increased by the bright field transmission electron microscopy (BF TEM) images and the selected area electron diffraction (SAED) patterns. In a high resolution transmission electron microscopy (HRTEM) study, it shows that $350^{\circ}C$-annealed InSb phases have {111} facet because the surface energy of a {111} close-packed plane is the lowest in FCC crystals. When the film was heated up to $400^{\circ}C$, $In_3SbTe_2$ grains have coherent micro-twins with {111} mirror plane, and they are healed annealing at $450^{\circ}C$. From the HRTEM, InTe phase separation was occurred in this stage. It can be found that $In_3SbTe_2$ forms in the crystallization process as composition of the film near stoichiometric composition, while InTe phase separation may take place as the composition deviates from $In_3SbTe_2$.

• Cross-Cultural Studies
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• v.49
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• pp.59-93
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• 2017

This paper provides an in-depth examination of the relationship between cinema and Giorgio Agamben's aesthetics and philosophy. Intersecting Agamben's key concepts including gesture, mediality, biopolitics, historicity, and profanation with historical and aesthetic dimensions of cinema, I argue for his ambivalent view on cinema and visual media. On the one hand, Agamben linked cinema and visual media to his discussion on biopolitics and spectacle as he considered them as apparatus for capturing and controlling gestures. On the other hand, he also argued that cinema could restore the image with capacity to preserve and recuperate gestures based on his consideration of montage as cinema's key aesthetic and technical component (an operation of profanation) and his Benjaminian thought on the ways in which montage suspended linear flow of images and activated an alternative memory of them. Drawing on history of cinema and optical devices in the 19th and early 20th centuries as well as examples of found footages of filmmaking predicated upon stoppage and repetition of images, I argue that Agamben's concept of potentialities can be extended into his thought on cinema and visual media apparatuses in general.