• 한국진공학회:학술대회논문집
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• 한국진공학회 2011년도 제40회 동계학술대회 초록집
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• pp.181-182
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• 2011

Phase-change materials can be cycled by exposure to laser beam, and as a function of the pulse intensity and duration, the laser beam triggers the switching from crystalline to amorphous phase and back. In other to progress better crystallization transition and amorphization long phase-transformation data of phase-change memory (PRAM), we investigated about the effect of Sb doping and Ag ions percolating into Ge-Se-Te phase-change material. Doped Sb concentrations was determined each of 10, 20 and 30 wt%. As the Sb-doping concentration was increased, the resistivity decreased and the crystallization temperature increased. Ionization of Ag was progressed by DPSS laser (532 nm) for 1 hour. The resistivity was more decreased and the crystallization temperature was more increased in case of adding Ag layer under Sb-(Ge-Se-Te) thin film. At the every condition of thin films included Ag layer more stable states were indicated compare with just Sb-doped Ge-Se-Te thin films.

• 한국정밀공학회지
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• 제24권5호
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• pp.104-109
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• 2007

Photochemical patterning of self-assembled mono layers (SAMs) has been performed by diode pumped solid state (DPSS) 3rd harmonic Nd:$YVO_4$ laser with wavelength of 355 nm. SAMs patternings of parallel lines have subsequently been used either to generate compositional chemical patterns or fabricate microstructures by a wet etching. This paper describes a selective etching process with patterned SAMs of alkanetiolate molecules on the surface of gold. SAMs formed by the adsorption of alkanethiols onto gold substrate employs as very thin photoresists. In this paper, the influence of the interaction between the functional group of SAMs and the etching solution is studied with optimal laser irradiation conditions. The results show that hydrophobic functional groups of SAMs are more effective for selective chemical etching than the hydrophilic ones.

• Journal of Information Display
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• 제10권1호
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• pp.33-36
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• 2009

A new hybrid silicon thin-film transistor (TFT) fabrication process using the DPSS laser crystallization technique was developed in this study to realize low-temperature poly-Si (LTPS) and a-Si:H TFTs on the same substrate as a backplane of the active-matrix liquid crystal flat-panel display (AMLCD). LTPS TFTs were integrated into the peripheral area of the activematrix LCD panel for the gate driver circuit, and a-Si:H TFTs were used as a switching device of the pixel electrode in the active area. The technology was developed based on the current a-Si:H TFT fabrication process in the bottom-gate, back-channel etch-type configuration. The ion-doping and activation processes, which are required in the conventional LTPS technology, were thus not introduced, and the field effect mobility values of $4\sim5cm^2/V{\cdot}s$ and $0.5cm^2/V{\cdot}s$ for the LTPS and a-Si:H TFTs, respectively, were obtained. The application of this technology was demonstrated on the 14.1" WXGA+(1440$\times$900) AMLCD panel, and a smaller area, lower power consumption, higher reliability, and lower photosensitivity were realized in the gate driver circuit that was fabricated in this process compared with the a-Si:H TFT gate driver integration circuit

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 2006년도 추계학술대회 논문집 Vol.19
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• pp.112-113
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• 2006

In this paper. we investigated a characteristic of holographic grating data erasure with non-polarized beam at amorphous chalcogenide As-Ge-Se-S thin film. A sample of holographic grating data was formed with DPSS laser for setup. Then, the erasure process was performed with He-Ne laser vertically at sample. As-Ge-Se-S(single layer). Ag/As-Ge-Se-S(double layer) and As-Ge-Se-S/Ag/As-Ge-Se-S(multi-layer) are manufactured to compare their characteristic of erasure.

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 2006년도 추계학술대회 논문집 Vol.19
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• pp.83-84
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• 2006

For phase transition method, good recording sensitivity, low heat radiation, fast crystallization and hi-resolution are essential. Also, A retention time is very important part for phase transition. In our presentation wall, we chose Ge-Se-Te material to use a Se material which has good optical sensitivity than Sb. A Ge-Se-Te sample was fabricated and Irradiated with He-Ne laser and DPSS laser to investigate a reversible phase change by light.

• 한국진공학회:학술대회논문집
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• 한국진공학회 2010년도 제39회 하계학술대회 초록집
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• pp.107-107
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• 2010

In this study, we have investigated the holographic grating formation on Ag-doped amorphous chalcogenide AsGeSeS thin films with Ag thickness. Ag/AsGeSeS thin films with the incident laser beam wavelength for the improvement of the polarization diffraction grating efficiency. Holographic gratings have been formed using Diode Pumped Solid State laser (DPSS, 532.0nm) under [P:P] polarized the intensity polarization holography. The diffraction efficiency was obtained by +1st order intensity. The result is shown that the diffraction efficiency of Ag/AsGeSeS double layer thin film for the Ag thickness, the maximum grating diffraction efficiency using 60nm Ag layer is 0.96%.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2006년도 제37회 하계학술대회 논문집 C
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• pp.1430-1431
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• 2006

We investigated the formation of 2-dimension hologram grating by means of selective etching characteristic and photo-expansion effect according to photo irradiation on amorphous As-Ge-Se-S thin film. By method of phase holography, we made the 2-dimensional hologram grating by each (S:P) and ($+45^{\circ}:-45^{\circ}$) polarized beam with DPSS laser(532nm) and He-Ne laser(632nm). A recording property was observed at each polarized beam through 2-dimensional hologram surface relief grating. Chalcogenide thin film was etched selectively by NaOH solution after the formation of 1-dimensional diffraction grating. And then etched sample was rotated 90 degree to fabricate 2 dimensional hologram grating. We found that it was observed the formation of 2-dimensional hologram grating by AFM(Atomic Force Microscopy).

• Current Optics and Photonics
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• 제3권6호
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• pp.577-582
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• 2019

We report on a continuous-wave (cw) optical parametric oscillator (OPO) optimized for mid-infrared emission above 5.0 ㎛. The OPO is based on a magnesium-oxide-doped periodically poled LiNbO₃(MgO:PPLN) crystal with a fan-out grating design. A linear two-mirror cavity resonating both at the pump and signal wavelengths is stabilized to the pump laser by using the modified Pound-Drever-Hall (PDH) method. The idler wavelength is continuously tunable from 4.7 ㎛ up to 5.3 ㎛ by varying the poling period of the fan-out grating crystal. Pumped by a diode-pumped solid state (DPSS) laser with a power of 1.1 W at 1064 nm, the maximum idler output power is measured to be 5.3 mW at 4.8 ㎛. The output power above 5.0 ㎛ is reduced to the hundreds of ㎼ level due to increased absorption in the crystal, but is stable and strong enough to be measured with a conventional detector.

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 2008년도 하계학술대회 논문집 Vol.9
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• pp.191-192
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• 2008

For phase transition method, good record sensitivity, low heat radiation, fast crystallization and hi-resolution are essential. Also, a retention time is very important part for phase-transition. In our past papers, we chose composition of $Ge_1Se_1Te_2$ material to use a Se factor which has good optical sensitivity than conventional Sb. Ge-Se-Te and Ag/$Ge_1Se_1Te_2$ samples are fabricated and irradiated with He-Ne laser and DPSS laser to investigate a reversible phase change by light. Because of Ag ions, the Ag layer inserted sample showed better performance than conventional one. We should note that this novel one showed another possibility for phase-change random access memory.

• 한국자기학회지
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• 제14권6호
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• pp.228-231
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• 2004

Ta(5 nm)/NiFe(11 nm)/FeMn(16 nm) Ta(5 nm)과 Ta(5 nm)/NiFe(11 run)/FeMn(16 nm)/NiFe(7 nm)/Ta(5 nm) 다층박막구조를 제작하여, Laser의 power, 조사 위치, 자장의 방향에 따라 자기저항(MR)비와 교환결합력(H$_{ex}$) 자기적 특성을 연구하였다. Laser 열처리는 power를 440 mW까지 증가시키면서 FeMn/NiFe 이중박막을 15분 씩 Laser로 조사하여, 200 mW에서부터 음의 자기장에서 자기저항곡선의 피크가 발생하기 시작하였다. 400 mW까지 증가시키면서 양의 자기장에서 자기저항곡선의 MR비와 H$_{ex}$:가 각각 0.9%에서 0.1%로, 87 Oe에서 76 Oe로 감소하였고, 음의 자기장 피크에서는 MR비와 H$_{ex}$가 모두 증가하였다. 또한 NiFe/FeMn/NiFe삼중박막에서도 같은 결과를 얻었다. 300 mA로 laser열처리한 면적을 증가시켰을 때 자기저항곡선이 positive 피크는 감소하고 negative 피크는 증가하였다. 이러한 Laser 열처리효과에 의해 결과적으로 교환결합된 박막구조의 국소적 자화반전을 가능하게 하였다.