• Korean Journal of Optics and Photonics
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• v.6 no.3
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• pp.214-221
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• 1995

When the broad pressure region (0.5-3.5 atm) of laser media is pumped by 70 ns [FWHM] electronbeam accelerator (800 kV, 21 kA), the correlation between free-runnuing XeF$(C\rightarrowA$ excimer laser output and Xe concentration are studied. The resonator consisted of dichroic output coupler, and the laser output is optimized with laser media $(Xe/F_2/Ar)$ as functions of total pressure and gas mixing ratio. Under the condition of F2 0.46% fixed, the laser intrinsic efficiencies of 0.38%, 1.03%, and 0.29% are obtained at 1. 2, and 3 atm, respectively. So then the peaks of laser intrinsic efficiency occured to the higher Xe concentration with decreasing total gas pressure. By analyzing the kinetics for the $XeF^*(C)$ formation efficiency and XeF$(C\rightarrowA$ laser extraction efficiency the dependence of Xe concentration on their correlation is explained. As the results we propose efficient operation of an atmosphericpressure XeF$(C\rightarrowA$ laser. laser.

• Korean Journal of Optics and Photonics
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• v.6 no.3
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• pp.201-213
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• 1995

By the use of computer simulation including collisional mixing kinetic processes of the B- and C-state in the upper laser level the output characteristics of electron-beam pumped XeF$(C\rightarrowA$ excimer laser are analyzed. We compared the results between experiments and simulations for the $XeF^*(C)$ formation that correlated the number of densities of the $XeF^*(B)$. We obtained good agreement$(28.5 mJ\pm5%)$ with comparisons between experiment and simulation and confirmed the optimal gas mixing ratio of $Xe/F_2/Ar=5.26/0.49/94.28%$ at atmospheric pressure laser medium under the condition of 70 ns [FWHM] electron-beam (800 kV, 21 kA). Also through the simulation we have investigated that the $XeF^*(C)$ formation channel, the $XeF^*(C)$ relaxation channel, and the absorption channel of bluegreen wavelength region as a function of F2 halogen donor and Xe partial pressure. ssure.

• Proceedings of the Korean Vacuum Society Conference
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• 1999.07a
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• pp.233-233
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• 1999

본 연구에서는 2성분계 gas(Ne+Xe)를 사용하여 기체압력(p), 진동수(f)에 따라 VUV(Vacuum Ultra Violet) spectrum 147, 173nm 파장과 IR(Infrared) spectrum 823nm, 828nm을 Vacuum Monochromator(Acton-VM 507)를 통해 측정하였다. 휘도(Luminance)와 전력(Power)측면에서 Ne+ Xe 최적의 가스 조성비를 찾기 위해서 Xe의 혼합비에 따른 IR영역인 823nm, 828nm을 측정결과, Xe 4%일 때 좋은 효율을 나타냈다. 기체압력이 200Torr에서는 Xe(3P1)에 기인하는 147nm가 주요한 파장이며, 기체압력이 400Torr, 600Torr일때는 Xe(3P2)에 기인하는 173nm 파장이 주요함을 알 수 있었다. 또한 공간 방전 이미지를 전압 pulse 인가후 ICCD Camera(V-Tek)의 Ready time, On Time을 조절하면서 50ns delay로 관측하였다. 향후 실험계획은 실제 상용화되고 있는 혼합가스 He+Ne+Xe의 조성비에 따른 자세한 실험을 할 것이다.

• 한국정보디스플레이학회:학술대회논문집
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• 2003.07a
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• pp.339-342
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• 2003

Main PDP panel efficacy improvement factors are discussed. A large panel efficacy improvement can be obtained through a combination of discharge efficiency improvement and phosphor improvement. Important design elements are a high Xe-content gas mixture, the application of a $TiO_2-layer$, and a new green phosphor with little saturation at high VUV-load. In a 4-inch color test panel with a conventional stripe-type cell configuration a white efficacy of 4.4 lm/W and a luminance of 5000 $cd/m^2$ is obtained for sustaining at 250V in addressed condition.

• Applied Chemistry for Engineering
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• v.21 no.4
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• pp.475-478
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• 2010

Fluorinated polymeric membranes were prepared by direct surface modification of PDMS with fluorine gas ($50{\sim}2000\;{\mu}mol/mol$ in nitrogen). The formed fluorinated polymeric membranes were characterized by FT-IR spectroscopy, GC (Gas chromatography), atomic force microscopy, and scanning electron microscopy. Direct fluorination resulted in the change of permeability and selectivity of various gases (pure gases such as $CO_2$, $O_2$, $N_2$, $C_2H_4$, mixture of He, Ne, Kr, Xe) through PDMS membranes. Fluorination resulted in the maximum 50% increase of selectivity through PDMS membrane.

• Applied Microscopy
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• v.45 no.4
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• pp.195-198
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• 2015

Gas-assisted etching (GAE) with focused ion beam (FIB) was applied to prepare plan-view specimens of Cu thin-layer on a silicon substrate for transmission electron microscopy (TEM). GAE using $XeF_2$ gas selectively etched the silicon substrate without volume loss of the Cu thin-layer. The plan-view specimen of the Cu thin film prepared by FIB milling with GAE was observed by scanning electron microscopy and $C_S$-corrected high-resolution TEM to estimate the size and microstructure of the TEM specimen. The GAE with FIB technique overcame various artifacts of conventional FIB milling technique such as bending, shrinking and non-uniform thickness of the TEM specimens. The Cu thin film was uniform in thickness and relatively larger in size despite of the thickness of <200 nm.

• Proceedings of the Korean Vacuum Society Conference
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• 1997.07a
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• pp.169-172
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• 1997

MgO dielectric pprotection layer is ppreppared by R.F. reactive magnetron spputtering with Mg target under various conditions of spputtering ppressure, time and substrate tempperature. Discharge characteristics of ppDpp is also studied as a pparameter of MgO pprepparation conditions. As the working ppressure and substrate tempperature was increase, the discharge voltage was decreased. Two kinds of MgO ppreppared both spputtering and E-beam methods were stable after annealing at 35$0^{\circ}C$ for 120min. discharge voltage under 3 mixed gas(He+Xe0.2%+Ne30%) was V=130V, V=102V and ${\gamma}$ coefficient was twiced as much as that of dielectric layer.

• Journal of Sensor Science and Technology
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• v.22 no.5
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• pp.369-373
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• 2013

In this paper, we developed contact type temperature sensor with single crystal silicon strip thermopile. This sensor consists of 15 p-type single crystal silicon strips, 17 n-types and contact electrodes on silicon dioxide silicon membrane. The result of electromotive force measuring showed very good characteristic as $15.18mV/^{\circ}C$ when temperature difference between the two ends of the thermopile occurs by applying thermal contact on the thermopile which was fabricated with silicon strip of $200{\mu}m$ length, $20{\mu}m$ width, $1{\mu}m$ thickness.

• Proceedings of the KSME Conference
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• 2007.05a
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• pp.1613-1616
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• 2007

A microgripper using thermal actuator and SU-8 polymer was designed and fabricated to manipulate cells and microparts. A chip size of a microgripper was 3 mm ${\times}$ 5 mm. The thermally actuated microgripper consisted of two couples of hot and cold arm actuators. The high thermal expansion coefficient, 52 $ppm/^{\circ}C$, of SU-8 compared to silicon and metals, allows the actuation of the microgripper. Thickness and width of SU-8 as an end-effector were 26 ${\mu}m$ and 80 ${\mu}m$, respectively. Initial gap between left jaw and right jaw was 120 ${\mu}m$. The ANSYS program as FEM tool was introduced to analyze the thermal distribution and displacement induced by thermal actuators. $XeF_2$ gas was used for isotropic silicon dry etching process to release SU-8 end-effector. Mechanical displacements of the fabricated microgripper were measured by optical microscopy in the range of input voltage from 0 V to 2.5 V. The maximum displacement between two jaws of a microgripper Type OG 1_1 was 22.4 ${\mu}m$ at 2.5 V.

• Proceedings of the Korean Vacuum Society Conference
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• 2013.02a
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• pp.630-630
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• 2013

Recently, atomically smooth hexagonal boron nitride(h-BN) known as a white graphene has drawn great attention since the discovery of graphene. h-BN is a III-V compound and has a honeycomb structure very similar to graphene with smaller lattice mismatch. Because of strong covalent sp2bonds like graphene, h-BN provides a high thermal conductivity and mechanical strength as well as chemical stability of h-BN superior to graphene. While graphene has a high electrical conductivity, h-BN has a highly dielectric property as an insulator with optical band gap up to 6eV. Similar to the graphene, h-BN can be applied to a variety of field, such as gate dielectric layers/substrate, ultraviolet emitter, transparent membrane, and protective coatings. However, up until recently, obtaining and controlling good quality monolayer h-BN layers have been too difficult and challenging. In this work, we investigate the controlled synthesis of h-BN layers according to the growth condition, time, temperature, and gas partial pressure. h-BN is obtained by using chemical vapor deposition on Cu foil with ammonia borane (BH3NH3) as a source for h-BN. Scanning Transmission Electron Microscopy (STEM, JEOL-JEM-ARM200F) is used for imaging and structural analysis of h-BN layer. Sample's surface morphology is characterized by Field emission scanning electron microscopy (SEM, JEOL JSM-7100F). h-BN is analyzed by Raman spectroscopy (HORIBA, ARAMIS) and its topographic variations by Atomic force microscopy (AFM, Park Systems XE-100).