• Laser Solutions
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• v.15 no.2
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• pp.1-5
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• 2012

Gelatin is used as a model for soft biological tissues in studying laser interaction with the soft tissues. In this work, we analyze the interaction between gelatin and excimer and Ti:Sapphire femtosecond laser under various conditions, especially by varying the laser, laser fluence and pulse number. The results show that swelling of the surface and ablation depth can be controlled by adjusting the process parameters.

• Laser Solutions
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• v.13 no.1
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• pp.1-5
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• 2010

ln this work, the feasibility of using a UV laser for micromachining of powder injection molded parts is examined experimentally. The results, although preliminary, indicate that microfabrication of various parts by laser micromachining of the injection molded parts and then sintering is promising. Particularly, micromachining of a mixture composed of stainless steel particles and polyrner binders was studied using a KrF excimer laser.

• Macromolecular Research
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• v.12 no.5
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• pp.540-543
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• 2004

Surface treatment using an excimer pulse laser beam has been conducted in order to increase the adhesive strength of vulcanized rubber. The adhesive strength increased with increasing the number of irradiation time with laser pulses and reached to 1,500 N/m after 100 cycles of irradiation. Increased in energy density was directly proportional to the improvement of the adhesive strength. Maximum value of the adhesive strength of 1,500 N/m obtained at the energy density of 176 mJ/$\textrm{cm}^2$. We conclude that an increased energy density improves in both the surface area and adhesive strength.

• Proceedings of the KIEE Conference
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• 1994.07b
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• pp.1239-1242
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• 1994

We have characterized XeCl excimer-laser-induced crystallization of thin amorphous silicon films deposited by PECVD (${\alpha}-Si:H$) and LPCVD(${\alpha}-Si$). The electrical and optical properties and surface roughness of crystallized thin films have been measured. The dc conductivities, crystallinity and surface roughness of the films increased as the laser energy density and shot density were increased. Also, we have investigated the effects of 2-step annealing employing SPC and ELA. The properties of 2-step annealed films were better than those of films annealed by ELA only.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2000.07a
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• pp.324-327
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• 2000

In this paper, the effects of negative and positive bias stress on p-channel poly-Si TFT's fabricated by excimer laser annealing have been investigated After positive and negative bias stress, transcon-ductance(g$_{m}$) is increased because of a reduction of the effective channel length due to the injected electron in the gate oxide. In the positive bias stress, the injection of hole is appeared after stress time of 3600sec and g$_{m}$ is decreased. On the other hand, the gate voltage at the maximum g$_{m}$, S-swing and threshold voltage(V$_{th}$) are decreased because of the interface state generation due to the injection of electrons into the gate oxide.e.ide.e.

• The Transactions of the Korean Institute of Electrical Engineers
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• v.45 no.4
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• pp.568-573
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• 1996

The amorphous silicon films deposited by low pressure chemical vapor deposition are crystallized by the various annealing techniques including low-temperature furnace annealing and two-step annealing. Two-step annealing is the combination of furnace annealing at 600 [.deg. C] for 24 h and the sequential furnace annealing at 950 [.deg. C] 1h or the excimer laser annealing. It s found that two-step annealings reduce the in-grain defects significantly without changing the grain boundary structure. The performance of the poly-Si thin film transistors (TFTs) produced by employing the tow-step annealing has been improved significantly compared with those of one-step annealing. (author). 13 refs., 6 figs., 1 tab.

• The Transactions of the Korean Institute of Electrical Engineers C
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• v.52 no.12
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• pp.559-561
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• 2003

We report a new excimer laser annealing method which successfully results in a single grain boundary formation in the channel of polycrystalline silicon thin film transistor. The proposed method is based on lateral grain growth and employs aluminum patterns which act as selective beam mask and lateral heat sink. The maximum grain size obtained by the proposed method is about 1.6${\mu}{\textrm}{m}$ in the length. The grainboundaries should be arranged parallel with the direction of current flow for the best device performance, so we propose a new device fabrication method and a new poly-Si TFT structure. Poly-Si TFT fabricated by the proposed method exhibits considerably improved electrical characteristics, such as high field effect mobility exceeding 240 $cm^2$/Vsec.

• Transactions on Electrical and Electronic Materials
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• v.4 no.5
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• pp.33-37
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• 2003

This study was performed to investigate the deposition mechanism of SiO$_2$ by ArF excimer laser(l93nm) CVD with Si$_2$H$\_$6/ and N$_2$O gas mixture and evaluate laser CVD quantitatively by modeling. With ArF excimer laser CVD, thin films can be deposited at low temperature(below 300$^{\circ}C$), with less damage and good uniformity owing to generation of conformal reaction species by singular wavelength of the laser beam. In this study, new model of SiO$_2$ deposition process by laser CVD was introduced and deposition rate was simulated by computer with the basis on this modeling. And simulation results were compared with experimental results measured at various conditions such as reaction gas ratio, chamber pressure, substrate temperature and laser beam intensity.

• Proceedings of the KIEE Conference
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• 1996.11a
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• pp.251-253
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• 1996

High temperature superconducting (HTS) target has been irradiated by excimer laser beam. The surface of HTS target has been changed and showed the formation of cones. The laser ablated HTS target surface has been systematically studied using a scanning electron microscope. A KrF excimer laser with a wavelength of 248 nm was used to ablate the HTS YBCO target. The size of laser beam focused on the target showed a rectangular shape of $9.7{\times}2\;mm^2$. The image of SEM shows the difference between the shapes of cones fanned at the boundary and at the center of the ablated area after 1,000 laser pulses.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2005.07a
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• pp.445-446
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• 2005

This letter reports the fabrication of polycrystalline silicon thin-film transistors (poly-Si TFT) on flexible plastic substrates using amorphous silicon (a-Si) precursor films by sputter deposition. The a-Si films were deposited with mixture gas of argon and helium to minimize the argon incorporation into the film. The precursor films were then laser crystallized using XeCl excimer laser irradiation and a four-mask-processed poly-Si TFTs were fabricated with fully self-aligned top gate structure.