• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• v.9 no.1
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• pp.1104-1105
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• 2005

최근 에너지 위기와 함께 대형 엑시머 레이저의 효율을 향상시키고자 하는 연구가 선진 각국에서 진행되고 있다. 본 연구에서는 방전으로 여기 되는 대형 엑시머 레이저를 이론적으로 해석하기 위한 방법을 제시한다.

• Archives of Pharmacal Research
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• v.15 no.3
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• pp.196-203
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• 1992

Intramolecular excimer formation of 1, 3-di(1-pyrenyl)propane (Py-3-Py) and fluorescence polarization of 1, 6-diphenyl-1, 3, 5-hexatriene (DPH) were used to investigate the effects of barbiturates on the fluidity of model membranes of phosphatidycholine (SPMVPC), phosphatidylserine (SPMVPS), and phosphatidylinositol (SPMVPI) fractions of synaptosomal plasma membrane vesicles (SPMV) isolated from bovine cerebral cortex. In a dose-dependent manner, barbiturates decreased the excimer to monomer fluorescence intensity ratio (I'/I) of Py-3-Py and increased the anisotropy(r), rotational relaxation time (P), limiting anisotropy $(r_infty)$, and order parameter (S) of DPH in SPMVPC, SPMVPS and SPMVPI. This indicates that barbiturates decreased both the lateral and rotational diffusion of the probes in SPMVPC, SPMVPS and SPMVPI. The relative potencies of barbiturates in ordering the membranes were in the order: pentobarbital > hexobarbital > amobarbital > phenobarbital. This order correlates well with the anesthetic potencies of barbiturates and the potencies for enhancement of $\gamma$-aminobutyric acid-stimulated chloride uptake. Thus, it is strongly suggested that a close relationship might exist between the membrane ordering effects of barbiturates and the chloride fluxes across SPMV.

• Korean Journal of Optics and Photonics
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• v.7 no.3
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• pp.232-237
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• 1996

A 500 Hz repetition rate excimer laser was developed as light source for pollution lidar. In this paper, the high repetitive output characteristics, the gas flow loop structure, and CR(clearing ratio) characteristics were investigated. Our laser system was constructed compact structure with a streamline gas flow loop and UV preionization. The real gas volume of laser is 10 liter. At 500 Hz repetitive operation, we have obtained average power of 53 watt with KrF laser gas. The variation of laser output, CR, and active volume are $\pm$6.7%, 2.3, and 2.0(H)$\times$1.2(W)$\times$56(L)=134 ㎤, respectively. Laser output power is declined to half at 3$\times$$10^6$ shots.

• Proceedings of the Materials Research Society of Korea Conference
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• 2003.11a
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• pp.200-200
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• 2003

Polycrystalline Si(polysilicon) TFTs have opened a way for the next generation of display devices, due to their higher mobility of charge carriers relative to a-Si TFTs. The polysilicon W applications extend from the current Liquid Crystal Displays to the next generation Organic Light Emitting Diodes (OLED) displays. In particular, the OLED devices require a stricter control of properties of gate oxide layer, polysilicon layer, and their interface. The polysilicon layer is generally obtained by annealing thin film a-Si layer using techniques such as solid phase crystallization and excimer laser annealing. Typically laser-crystallized Si films have grain sizes of less than 1 micron, and their electrical/dielectric properties are strongly affected by the presence of grain boundaries. Impedance spectroscopy allows the frequency-dependent measurement of impedance and can be applied to inteface-controlled materials, resolving the respective contributions of grain boundaries, interfaces, and/or surface. Impedance spectroscopy was applied to laser-annealed Si thin films, using the electrodes which are designed specially for thin films. In order to understand the effect of grain size on physical properties, the amorphous Si was exposed to different laser energy densities, thereby varying the grain size of the resulting films. The microstructural characterization was carried out to accompany the electrical/dielectric properties obtained using the impedance spectroscopy, The correlation will be made between Si grain size and the corresponding electrical/dielectric properties. The ramifications will be discussed in conjunction with active-matrix thin film transistors for Active Matrix OLED.

• 한국정보디스플레이학회:학술대회논문집
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• 2003.07a
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• pp.634-638
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• 2003

We reported the a-Si crystallization using a XeCl excimer laser annealing on the plastic substrate. The poly-Si film is able to grow in the low temperature and light substrate like a plastic. For the preparation of sample, substrate is cleaned by organic liquids. The film of $CeO_{2}$ layer as the buffer layer was grown by sputtering methods. After a-Si film deposition using ICPCVD, the film was crystallized by XeCl excimer laser. In this paper, we present the crystallization properties of a-Si on the plastic substrate

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2008.11a
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• pp.80-81
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• 2008

Schottky barrier thin film transistors (SB-TFT) on polycrystalline silicon(poly-Si) are fabricated by platinum silicided source/drain for p-type SB-TFT. High quality poly-Si film were obtained by crystallizing the amorphous Si film with excimer laser annealing (ELA) or solid phase crystallization (SPC) method. The fabricated poly-Si SB-TFTs showed low leakage current level and a large on/off current ratio larger than $10^5$. Significant improvement of electrical characteristics were obtained by the additional forming gas annealing in 2% $H_2/N_2$ ambient, which is attributed to the termination of dangling bond at the poly-Si grain boundaries as well as the reduction of interface trap states at gate oxide/poly-Si channel.

• Journal of Photoscience
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• v.8 no.3_4
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• pp.87-92
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• 2001

Intramolecular excimer formation of 1,3-di(1-pyrenyl)propane (Py-3-Py) and fluorescence polarization of 1,6-diphenyl-1,3,5-hexatriene (DPH) were used to investigate the effects of parathyroid hormone (PTH) on the bulk bilayer fluidity of the plasma membrane vesicles isolated from cultured osteoblasts (OB-PMV). In a dose-dependent manner, rat PTH-(1-34) [rPTH-(1-34)] increased the excimer to monomer fluorescence intensity ratio (I'/I) of Py-3-Py and decreased the anisotropy (r) of DPH in OB-PMV. This indicates that PTH increased both the lateral and rotational diffusion of the probes in OB-PMY. Selective quenching of DPH fluorescence by trinitrophenyl groups was utilized to examine the transbilayer fluidity asymmetry of OB-PMV. The anisotropy, limiting anisotropy, and order parameter of DPH in the inner monolayer were 0.024, 0.032, and 0.062 greater than calculated for the outer monolayer of OB-PMY. Selective quenching of DPH fluorescence by trinitrophenyl groups was also utilized to examine the transbilayer effects of PTH on the fluidity of OB-PMV. rPTH-(1-34) had a greater fluidizing effect on the outer monolayer as compared to the inner monolayer of OB-PMV. Thus, it has been proven that PTH exhibits a selective rather than nonselective fluidizing effect within transbilayer domains of OB-PMV.

• International Journal of CAD/CAM
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• v.6 no.1
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• pp.183-192
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• 2006

A CAD/CAM system has been developed for rapid prototyping (RP) of microfluidic devices based on excimer laser micromachining. The system comprises of two complementary softwares. One, the CAM tool, creates part programs from CAD models. The other, the Simulator Tool, uses a part program to generate the laser tool path and the 2D and 3D graphical representation of the machined microstructure. The CAM tool's algorithms use the 3D geometry of a microstructure, defined as an STL file exported from a CAD system, and process parameters (laser fluence, pulse repetition frequency, number of shots per area, wall angle), to automatically generate Numerical Control (NC) part programs for the machine controller. The performance of the system has been verified and demonstrated by machining a particle transportation device. The CAM tool simplifies part programming and replaces the tedious trial-and-error approach to creating programs. The simulator tool accepts manual or computer generated part programs, and displays the tool path and the machined structure. This enables error checking and editing of the program before machining, and development of programs for complex microstructures. Combined, the tools provide a user-friendly CAD/CAM system environment for rapid prototyping of microfluidic devices.

• Journal of Advanced Marine Engineering and Technology
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• v.20 no.5
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• pp.93-102
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• 1996

Laser-induced plume and laser-target interaction during pulsed laser deposition are demonstrated for a lead zirconate titanate (PZT). A KrF excimer laser (wavelength 248nm) was used and the laser was pulsed at 20Hz, with nominal pulse width of 20ns. The laser fluence was~$16J/cm^2,$ with 100mJ per pulse. The laser-induced plasma plume for nanosecond laser irradiation on PZT target has been investigated by optical emission spectra using an optical multichannel analyzer(OMA) and by direct observation of the plume using an ICCD high speed photography. OMA analysis showed two distinct ionic species with different expansion velocities of fast or slow according to their ionization states. The ion velocity of the front surface of the developing plume was about $10^7$cm/sec and corresponding kinetic energy was about 100eV. ICCD photograph showed another kind of even slower moving particles ejected from the target. These particles considered expelled molten parts of the target. SEM morphologies of the laser irradiated targets showed drastic melting and material removal by the laser pulse, and also showed the evidence of the molten particle ejection. The physics of the plasma(plume) formation and particle ejection has been discussed.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2003.10a
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• pp.442-445
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• 2003

In this study, we developed the 40 J-class MPC(magnetic pulse compression) system for exciting excimer laser and investigated the optimal conditions of each stage of MPC circuit. This system consists of a DC power supply, a pulse transformer and four saturable inductors. The number of turns of saturable inductors at each stage of MPC circuit are 140, 25, 5, 1 and the optimal storage capacitance of each stage are 34 nF, 28.9 nF, 22.1 nF, respectively. In the improvement MPC system, we have obtained an output voltage of 43 kV, a current of 8.25 kA and a pulse duration of 360 ns. Also, the maximum pulse compression ratio of 77.7 and the current gain of 71.7 were obtained.