• Journal of Convergence for Information Technology
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• v.10 no.8
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• pp.137-143
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• 2020

This study examined the effects of rapid thermal annealing (RTA) on the physical and chemical characteristics of thin silver (Ag) layers on SiO2 coated metal foils. Ag layers were annealed at various temperatures of the range between 150 ℃ and 550 ℃ for 20 min. The surface roughness and resistivity are increased at the annealing temperatures of 550 ℃. We also found that oxygen (O) and silicon (Si) atoms exist at the Ag film surface by using compositional analysis in the annealing temperatures of 550 ℃. The total reflectance is decreased with increasing temperature. These phenomena are due to an out-diffusion of Si atoms from SiO2 layers during the RTA annealing. The results offer the possibility of using it as a substrate for various flexible optoelectronic devices.

• Journal of the Korean Vacuum Society
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• v.19 no.2
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• pp.155-160
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• 2010

The effect of process temperature of a final annealing step in the fabrication of phase change memory (PCM) devices was investigated. Discrete PCM devices employing $Ge_2Sb_2Te_5$ (GST) films as an active element were made in a pore-style configuration, and they were annealed at various temperatures ranging from 160 to $300^{\circ}C$. The behaviors of cell resistance change from SET resistance to RESET resistance were totally different according to the annealing temperatures. There was a critical annealing temperature for the fabrication of normal PCM devices and abnormal operations were observed in some devices annealed at temperatures lower or higher than the critical temperature. Those influences of annealing temperature seem closely related to the thermal stability of a top electrode/GST/heating layer multilayer structure in the PCM devices.

• Korean Journal of Materials Research
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• v.12 no.1
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• pp.75-81
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• 2002

The ferroelectric properties of Pb(Zr,Ti)O$_3$[PZT] films degrade when the films with Pt top electrodes are annealed in hydrogen containing environment. This is due to the reduction activity of atomic hydrogen that is generated by the catalytic activity of the Pt top electrode. At the initial stage of hydrogen annealing, oxygen vacancies are formed by the reduction activity of hydrogen mainly at the vicinity of top Pt/PZT interface, resulting in a shift of P-E (polarization-electric field) hysteresis curve toward the negative electric field direction. As the hydrogen annealing time increases, oxygen vacancies are formed inside the PZT film by the inward diffusion of hydrogen ions, as a result, the polarization degrades significantly and the degree of P-E curve shift decreases gradually. The direction and the magnitude of the remnant polarization in the PZT film affect the motion of hydrogen ions which determines the degradation of polarization characteristics and the shift in the P-E hysteresis curve of the PZT capacitor during hydrogen annealing. When the remnant polarization is formed in the PZT film by applying a pre-poling voltage prior to hydrogen annealing, the direction of the P-E curve shift induced by hydrogen annealing is opposite to the polarity of the pre-poling voltage. The hydrogen-induced degradation behavior of the PZT capacitor is also affected by the internal field that has been generated in the PZT film by the charges located at the top interface prior to hydrogen annealing.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.14 no.2
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• pp.287-295
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• 2010

In this paper, we introduce a novel approach to optimization algorithm which is a distributed Mean field Genetic algorithm (MGA) implemented in MPI(Message Passing Interface) environments. Distributed MGA is a hybrid algorithm of Mean Field Annealing(MFA) and Simulated annealing-like Genetic Algorithm(SGA). The proposed distributed MGA combines the benefit of rapid convergence property of MFA and the effective genetic operations of SGA. The proposed distributed MGA is applied to the channel routing problem, which is an important issue in the automatic layout design of VLSI circuits. Our experimental results show that the composition of heuristic methods improves the performance over GA alone in terms of mean execution time. It is also proved that the proposed distributed algorithm maintains the convergence properties of sequential algorithm while it achieves almost linear speedup as the problem size increases.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.18 no.3
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• pp.638-642
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• 2014

In this study, we investigate on the crystal microstructure and magneto-resistance (MR) change of Bismuth(Bi) thin films for annealing process, in order to apply Bi thin films to the spin electronic devices. As-prepared Bi thin films show the randomly oriented find grains whose size was measured to about 100 nm and the very low MR (4.7 % at room temperature) while careful annealing results in not only grain growth up to ${\sim}2{\mu}m$ but also drastic MR improvement (404 % at room temperature). The drastic change in the MR after applying the annealing process is attributed to the grain growth decreasing grain boundary scattering of electron. Therefore, in this study, we confirm the annealing effect for the grain boundary formation and MR improvement of Bi thin films, and demonstrate the feasibility of spin electronic devices.

• Transactions on Electrical and Electronic Materials
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• v.3 no.1
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• pp.14-17
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• 2002

The effects of substrate temperatures and annealing temperatures on the microstructures and ferroelectric properties of PbZ $r_{0.52}$ $Ti_{0.48}$ $O_3$(PZT) thin fims prepared by pulsed laser deposition (PLD) were investigated. For this purpose, the PZT films were deposited at various substrate temperatures (400~$600^{\circ}C$) with post annealing process in oxygen atmosphere. The single perovskite phase was formed at the deposition temperature of 500 to 55$0^{\circ}C$ without post annealing and the PZT films deposited below 50$0^{\circ}C$ formed the single phase with post annealing at $650^{\circ}C$. The grain size of the films increased and the grain boundary of the films was clearly defined as the substrate temperature increased from 400 to 55$0^{\circ}C$. The remnant polarization (Pr) and the coercive field (Ec) of the films deposited at 55$0^{\circ}C$ and annealed at $650^{\circ}C$ were 34.3 $\mu$C/c $m^2$and 60.2 kV/cm, respectively.y.y.

• Journal of the Korean Society for Heat Treatment
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• v.17 no.4
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• pp.223-229
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• 2004

The effects of the cooling and annealing conditions on the microstructures and corrosion properties were investigated for the Cu-contained Zr-Nb alloy (Zr-1.1Nb-0.07Cu). After annealing at $1050^{\circ}C$ for 15 min, the specimens were cooled by three methods of water quenching, air cooling, and furnace cooling. Widmanstatten structures were developed in both air- and furnace-cooled specimens, and the Widmanstatten plate width of the furnace-cooled specimens was wider than that of the air-cooled ones. The weight gain in the furnace-cooling case was higher than that in the air-cooling case. This could be the reason why the diffusion time was more enough during the furnace cooling than the air cooling. The oxide of the furnace-cooled specimen was nonunformly formed just beneath the Widmanstatten plate boundaries, where ${\beta}_{Zr}$ phases were exised concentrately. Compared with the $640^{\circ}C$ annealing after the water quenching, the $570^{\circ}C$ annealing could make the ${\beta}_{Nb}$ phases and a concomitant reduction of the Nb in the matrix, and then it could improve the corrosion resistance with the increase of the annealing time. It would be concluded that the corrosion resistance of the Zr-1.1Nb-0.07Cu was good when the Nb concentration in the matrix was reached at an equilibrium level and then the ${\beta}_{Nb}$ phase was formed.

• Journal of IKEEE
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• v.25 no.3
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• pp.467-472
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• 2021

Stable operation of semiconductor devices is needed even at high temperatures. Among the structures of semiconductor devices, the area that can cause unstable electrical responses at high temperatures is the contact layer between the metal and the semiconductor. In this study, the effect of annealing conditions included in the process of forming a contact layer of nickel silicide(NiSix) on a p-type SiC layer on the specific contact resistance of the contact layer and the total resistance between the metal and the semiconductor was investigated. To this end, a series of electrodes for TLM (transfer length method) measurements were patterned on the 4 inch p-type SiC layer under conditions of changing annealing temperature of 1700 and 1800 ℃ and annealing time of 30 and 60 minutes. As a result, it was confirmed that the annealing conditions affect the resistance of the contact layer and the electrical stability of the device.

• Journal of the Korean institute of surface engineering
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• v.54 no.2
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• pp.96-101
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• 2021

NaNbO₃:Eu³⁺ phosphor thin films were grown on quartz substrates by radio-frequency magnetron sputtering at a growth temperature of 100 ℃, with subsequent annealing at temperatures of 800, 900, and 1000 ℃. The effects of annealing temperature on the structural, morphological, and optical properties of the thin films were investigated. The NaNbO₃:Eu³⁺ sputtering target was synthesized by a solid-state reaction of raw materials Na₂CO₃, Nb₂O₅, and Eu₂O₃. The X-ray diffraction patterns exhibited that the thin films had two mixed phases of NaNbO₃ and Eu₂O₃. Surface morphologies were investigated by using field emission-scanning electron microscopy and indicated that the grains of the thin film annealed at 1000 ℃ showed irregular shapes with an average size of approximately 300 nm. The excitation spectra of Eu³⁺-doped NaNbO₃ thin film consisted of a strong charge transfer band centered at 304 nm in the range of 240-350 nm and two weak peaks at 395 and 462 nm, respectively, resulting from the ⁷F₀→⁵L₆ and ⁷F₀→⁵H₂ transitions of Eu³⁺ ions. The emission spectra under excitation at 304 nm exhibited an intense red band centered at 614 nm and two weak bands at 592 and 681 nm. As the annealing temperature increased from 800 ℃ to 1000 ℃, the intensities of all the emission bands and the band gap energies gradually increased. These results indicate that the higher annealing temperature enhance the luminescent properties of NaNbO₃:Eu³⁺ thin films.

• Journal of the Korean Society for Heat Treatment
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• v.32 no.3
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• pp.107-112
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• 2019

In order to investigate the effect of plastic deformation and annealing process parameters on strength and electrical conductivity of Cu-Fe alloys, Cu-10wt%Fe, Cu-15wt%Fe alloys were drawn up to ${\eta}=4$ and annealed in the temperature range of $300^{\circ}C$ to $700^{\circ}C$, followed by measurements of tensile strength and electric conductivity. As draw strain increases, tensile strength increases while electrical conductivity decreases. These observations result from reduction of dislocation density and decrease in Fe fiber spacing. Raising annealing temperature brought about decrease of tensile strength and increase of electrical conductivity up to $500^{\circ}C$, being followed by decreasing above $500^{\circ}C$. Such results are thought to be caused by decrease of dislocation density below $500^{\circ}C$ and rapid solubility increase of Fe in Cu above $500^{\circ}C$. For the purpose of obtaining both high strength and high conductivity, annealing process should be incorporated just prior to reaching to final draw strain. For Cu-10wt%Fe alloy, the tensile strength 706.9 MPa and the electrical conductivity 54.34%IACS were obtained through the processes of drawing up to ${\eta}=3$, annealing at $500^{\circ}C$ for 1 hour and additional drawing up to total strain of ${\eta}=4$.