• Journal of Sensor Science and Technology
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• v.5 no.2
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• pp.55-60
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• 1996

The growth and microwave plasma assisted nitrogen doping of ZnSe by low pressure organometallic vapor phase epitaxy(OMVPE) has been investigated in a vertical downflow reactor equipped with a laser interferometer for in-situ growth rate measurements. Particular emphasis is placed on understanding growth characteristics of $H_{2}Se$ and the new adduct source dimethylzinc:triethyllamine($DMZn:NEt_{3}$) as compared with those obtained with $H_{2}Se$ and DMZn. At lower temperatures ($<300^{\circ}C$) and pressures(<30Torr), growth rates are higher with the adduct source and the surface morphology is improved relative to films synthesized with DMZn. Hall measurements and photoluminescence spectra of the grown films demonstrate that DMZn and $DMZn:NEt_{3}$ produce material with comparable electronic and optical properties. Microwave plasma decomposition of ammonia is investigated as a possible approach to increasing nitrogen incorporation in ZnSe and photoluminescence spectra are compared to those realized with conventional ammonia doping.

• Proceedings of the IEEK Conference
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• 2002.06b
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• pp.29-32
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• 2002

This paper describes a novel structure of NMOSFET with elevated SiGe source/drain region and ultra-shallow source/drain extension(SDE)region. A new ultra-shallow junction formation technology. Which is based on damage-free process for rcplacing of low energy ion implantation, is realized using ultra-high vacuum chemical vapor deposition(UHVCVD) and excimer laser annealing(ELA).

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.29 no.6
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• pp.370-375
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• 2016

In this paper, we investigated the electrical properties of crystalline silicon solar cell fabricated with Ni/Cu/Ag plating. The laser process was used to ablate silicon nitride layer as well as to form the selective emitter. Phosphoric acid layer was spin-coated to prevent damage caused by laser and formed selective emitter during laser process. As a result, the contact resistance was decreased by lower sheet resistance in electrode region. Low sheet resistance was obtained by increasing laser current, but efficiency and open circuit voltage were decreased by damage on the wafer surface. KOH treatment was used to remove the laser damage on the silicon surface prior to metalization of the front electrode by Ni/Cu/Ag plating. Ni and Cu were plated for each 4 minutes and 16 minutes and very thin layer of Ag with $1{\mu}m$ thickness was plated onto Ni/Cu electrode for 30 seconds to prevent oxidation of the electrode. The silicon solar cells with KOH treatment showed the 0.2% improved efficiency compared to those without treatment.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 1999.11a
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• pp.561-565
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• 1999

We measured the optical properties in Ag/chalcogenide films with the exposure of 325nm-Held laser In addition we have investigated the Ag doping mechanism as considering the changes of Ag-concentration distribution and optical energy gap ( $E_{op}$ ) with Photon-dose. The "windows" characteristics of Ag thin film occur around the wavelength of 325 nm and the Ag is evaluated to be transparent, without an absorption, in the region. While the $E_{op}$ of S $b_2$ $S_3$ thin film was changed largely by an exposure of HeNe laser(632.8 nm) an exposure of HeCd laser resulted in relatively small variation of $E_{op}$ . Therefore it is thought that photon absorption at the metal layer plays an important role in Ag photodoping.on at the metal layer plays an important role in Ag photodoping.

• Progress in Superconductivity and Cryogenics
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• v.20 no.4
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• pp.41-45
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• 2018

We have investigated the effect of $Y_2O_3$ nanoparticles on the pinning properties of $Y_2O_3$-doped $GdBa_2Cu_3O_{7-{\delta}}$ (GdBCO) films. Both undoped and $Y_2O_3$-doped GdBCO films were grown on $CeO_2$-buffered MgO (100) single crystal substrates by pulsed laser deposition (PLD) using KrF (${\lambda}=248nm$) laser. The $Y_2O_3$ doping contents were controlled up to ~ 2.5 area% by varying the internal angles of $Y_2O_3$ sectors put on the top surface of GdBCO target. Compared with the $Gd_2O_3$-doped GdBCO films previously reported by our group [1], the $Y_2O_3$-doped GdBCO films exhibited less severe critical temperature ($T_c$) drop and thus slightly enhanced critical current densities ($J_c$) and pinning force densities ($F_p$) at 65 K for the applied field parallel to the c-axis of the GdBCO matrix (B//c) with increasing the doping content. Below 40 K, the in-field $J_c$ and $F_p$ values of all $Y_2O_3$-doped GdBCO films exhibited higher than those of undoped GdBCO film, suggesting that $Y_2O_3$ inclusions might act as effective pinning centers.

• Journal of the Korean Society for Heat Treatment
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• v.32 no.4
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• pp.155-160
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• 2019

Diamond Like Carbon (DLC) is a metastable form of amorphous carbon that have superior material properties such as high mechanical hardness, chemical inertness, abrasion resistance, and biocompatibility. Furthermore, its material properties can be tuned by additional doping such as nitrogen or boron. However, either pure DLC or doped DLC show poor adhesion property that makes it difficult to apply contact processing technique. Therefore we propose ultrafast laser micromachining which is non-contact precision process without mechanical degradation. In this study, we developed precision machining process of DLC thin film using an ultrafast laser by investigating the process window in terms of laser fluence and laser wavelength. We have also demonstrated various patterns on the film without generating any microcracks and debris.

• Resources Recycling
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• v.16 no.5
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• pp.46-50
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• 2007

Blue phosphor calcium aluminate, $CaAl_2O_4:Eu^{2+}$ co-doped with $Nd^{3+}$ was prepared by solid state synthesis method. Phosphor materials with 1 mol% $Eu^{2+}$ and varying compositions of $Nd^{3+}$ show high brightness and long persistent luminescence. The synthesized phosphor materials were investigated by powder x-ray diffraction (XRD), SEM, TEM, photoluminescence excitation and emission studies. Broad band UV excited luminescence of the $CaAl_2O_4:Eu^{2+}:Nd^{3+}$ was observed in the blue region (${\lambda}_{max}=440\;nm$) due to transitions from the $4f^65d^1$ to the $4f^7$ configuration of the $Eu^{2+}$ ion. $Nd^{3+}$ ion doping in the phosphor results in long afterglow phosphorescence when the excitation light is cut off.

• Proceedings of the KIEE Conference
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• 1999.07d
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• pp.1959-1961
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• 1999

We prepared the $Ag[100\AA])/Sb_2S_3[3000\AA]$ films using the thermal evaporator. The films were exposed by the blue-pass filtered mercury lamp and the polarized He-Ne laser. We have investigated the dependence of the induced optical energy with Ag-doping and have observed the transmittance variation near the optical absorption edge with the light source. It was shown that the energy gap of this thin film was largely changed by exposing He-Ne laser, the light source of the near energy gap of this thin film. It is because of the structural change from Ag-doping. It is investigated that the dissolution, the diffusion, and the field effect of the Ag thin film generate the Ag spatial distribution.

• Journal of Magnetics
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• v.13 no.3
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• pp.88-91
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• 2008

This study examined the effect of Sn co-doping on the transport and magnetic properties of Cr-doped $In_2O_3$ thin films grown on (100) silicon substrates by pulsed laser deposition. The experimental results showed that Sn co-doping enhances the magnetization and appearance of the anomalous Hall effect, and increases the carrier (electron) concentration. These results suggest that the conduction carrier plays an important role in enhancing the ferromagnetism of a laser-deposited Cr-doped $In_2O_3$ film, which may have applications in transparent oxide semiconductor spin electronics devices.

• ETRI Journal
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• v.25 no.4
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• pp.247-252
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• 2003

This paper presents results from experiments on laser-annealed SiGe-selective epitaxial growth (LA-SiGe-SEG). The SiGe-SEG technology is attractive for devices that require a low band gap and high mobility. However, it is difficult to make such devices because the SiGe and the highly doped region in the SiGe layer limit the thermal budget. This results in leakage and transient enhanced diffusion. To solve these problems, we grew in situ doped SiGe SEG film and annealed it on an XMR5121 high power XeCl excimer laser system. We successfully demonstrated this LA-SiGe-SEG technique with highly doped Ge and an ultra shallow junction on p-type Si (100). Analyzing the doping profiles of phosphorus, Ge compositions, surface morphology, and electric characteristics, we confirmed that the LA-SiGe-SEG technology is suitable for fabricating high-speed, low-power devices.