• Journal of the Korean Vacuum Society
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• v.5 no.4
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• pp.348-353
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• 1996

Rapid thermal annealing (RTA) was applied to polycrystalline CdTe thin films evaporated on CdS/ITO/glass substrate and the effect of the annealing temperatures and the atmosphere on physical properties of polycrystalline CdTe thin films and CdTe/CdS solar cell characteristics were studied. Results obtained by EDX showed that the bulk composition of CdTe remained stoichiometric after annealing at $550^{\circ}C$ in the air but the surface composition became Cd-rich. Cross-sectional TEM and micro EDX showed that columnar grains and micro-twins remained even after RTA, however, and the sulfur content in the annealed CdTe (added by sulfur diffusion from CdS during the annealing) was much smaller than that by furnace annealing. Among the investigated RTA temperatures and gas environments, the cell made with CdTe annealed at $550^{\circ}C$ in air showed the best solar energy conversion efficiency.

• 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.15 no.4
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• pp.252-256
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• 2005

We removed the bluish of the natural ruby successfully by vacuum annealing, and measured the color evolution with annealing time and temperature. We varied the anneal temperature and time $800\~1500^{\circ}C$ and $3\~26$ hrs, respectively. The color evolution of rubies with annealing condition was recorded by a digital camera and a color coordination visible spectrometer. We determined the optimum bluish eliminating annealing condition was $1500^{\circ}C-3hr$, which conserving the natural inclusions. We suggest the bluish shrink with diffusion coefficient of $D=(5\times10^{-3}){\exp}(-200.000/RT)[cm^2/s]$. We propose the color of ruby may be determined as the identical red color if the color difference between two samples are less than 1.0, and the color difference nay be an auxiliary standard to evaluate the color of rubies.

• Journal of Sensor Science and Technology
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• v.18 no.4
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• pp.316-321
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• 2009

Er-doped ZnO(ZnO:Er) films were deposited onto MgO wafers by ultrasonic spray pyrolysis at 550 $^{\circ}C$ varying the concentration of Er in the deposition source from 0.5 wt% to 3.0 wt%. Annealing of the films in a vacuum was carried out to increase the intensity of ultraviolet(UV) emission from the films. The annealing temperature was between 600$^{\circ}C$ and 800$^{\circ}C$. The crystallographic properties and surface morphology of the films were investigated by X-ray diffraction(XRD)and scanning electron microscope(SEM), respectively. The properties of photoluminescence(PL) for the films were investigated by the dependence of PL spectra on the annealing temperature. X-ray photoelectron spectroscopy(XPS) was conducted to find the composition change in the films by the annealing.

• JSTS:Journal of Semiconductor Technology and Science
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• v.8 no.3
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• pp.239-243
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• 2008

In this study, Bi-Sb thin film structure was prepared by thermal evaporation method. The electrical, optical transmission and structural characteristics of the prepared samples were introduced before and after thermal annealing process. At temperature of $500^{\circ}C$, the absorption of the structure was improved to reach 97% at near-infrared region. As well, the thermal annealing caused to reduce the bulk resistance of the Bi-Sb thin film structure. The morphology of Bi-Sb structure was also improved by thermal annealing as characteristic islands of the structure appear clearly in form hexagonal areas distinct from each other. This study is aiming to examine such structures if they are employed as photonic devices such as photodetectors, LED's and optical switches.

• The Transactions of the Korean Institute of Electrical Engineers C
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• v.54 no.1
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• pp.1-7
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• 2005

Thin films of vanadium oxide(VO/sub x/) were deposited by r.f. magnetron sputtering from V₂O/sub 5/ target with oxygen/(oxygen+argon) partial pressure ratio of 0% and 8% and in situ annealed in vacuum at 400℃ for 1h and 4h. Crystal structure, chemical composition, molecular structure, optical and electrical properties of films were characterized through XRD, XPS, RBS, FTIR, optical absorption and electrical conductivity measurements. The films as-deposited are amorphous, but 0%O₂ films annealed for time longer than 4h and 8% O₂ films annealed for time longer than 1h are polycrystalline. As the oxygen partial pressure is increased the films become more stoichiometric V₂O/sub 5/. When annealed at 400℃, the as-deposited films are reduced to a lower oxide. The optical transmission of the films annealed in vacuum decreases considerably than the as-deposited films and the optical absorption of all the films increases rapidly at wavelength shorter than about 550nm. Electrical conductivity and thermal activation energy are increased with increasing the annealing time and with decreasing the oxygen partial pressure.

• Journal of Korean Vacuum Science & Technology
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• v.4 no.1
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• pp.6-10
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• 2000

Ferroelectric YMnO$_3$ thin films were deposited on $Y_2$O$_3$/si(100) substrates by metalorganic chemical vapor deposition. The YMnO$_3$ thin films annealed in vacuum ambient (100 mTorr) above 75$0^{\circ}C$ show hexagonal structured YMnO$_3$. However, the film annealed in oxygen ambient shows poor crystallinity, and the second phase as $Y_2$O$_3$ and orthorhombic-YMnO$_3$ were shown. The annealing ambient and pressure on the crystallinity of YMnO$_3$ thin films is very important. The C-V characteristics have a hysteresis curve with a clockwise rotation, which indicates ferroelectric polarization switching behavior. When the gate voltage sweeps from +5 to 5 V, the memory window of the Pt/YMnO$_3$/Y$_2$O$_3$/Si gate capacitor annealed at 85$0^{\circ}C$ is 1.8 V. The typical leakage current densities of the films annealed in oxygen and vacuum ambient are about 10$^{-3}$ and 10$^{-7}$ A/cm$^2$ at applied voltage of 5 V.

• Journal of the Korean Society for Heat Treatment
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• v.27 no.4
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• pp.175-179
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• 2014

IGZO thin films were prepared by radio frequency (RF) magnetron sputtering on glass substrates and then annealed in vacuum for 30 minutes at 100, 200 and $300^{\circ}C$, respectively. The thickness of films kept at 100 nm by controlling the deposition rate. While the optical transmittance and sheet resistance of as deposited films were 91.9% and $901{\Omega}/{\Box}$, respectively, the films annealed at $300^{\circ}C$ show the optical transmittance of 95.4% and the sheet resistance of $383{\Omega}/{\Box}$. The experimental results indicate that vacuum-annealed IGZO film at $300^{\circ}C$ is an attractive candidate for the transparent thin film transistor (TTFT) in large area electronic applications.

• Proceedings of the Korean Vacuum Society Conference
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• 2013.08a
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• pp.318.1-318.1
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• 2013

Nowadays Cu2ZnSnS4 (CZTS) solar cell is attracting a lot of attention as a strong alternative to CIGS solar cell due to nontoxic and inexpensive constituent elements of CZTS. From various processes for the fabrication of CZTS solar cell, solution-based deposition of CZTS thin films is well-known non-vacuum process and many researchers are focusing on this method because of large-area deposition, high-throughput, and efficient material usage. Typically the solution-based process consists of two steps, coating of precursor solution and annealing of the precursor thin films. Unlike vacuum-based deposition, precursor solution contains unnecessary elements except Cu, Zn, Sn, and S in order to form high quality precursor thin films, and thus the precise control of precursor thin film preparation is essential for achieving high efficient CZTS solar cells. In this work, we have investigated the effect of preparation condition of CZTS precursor thin films on the performance of CZTS solar cells. The composition of CZTS precursor solution was controlled for obtaining optimized chemical composition of CZTS absorber layers for high-efficiency solar cells. Pre-annealing process of the CZTS precursor thin films was also investigated to confirm the effect of thermal treatment on chemical composition and carbon residues of CZTS absorber layers. The change of the morphology of CZTS precursor thin film by the preparation condition was also observed.

• Transactions on Electrical and Electronic Materials
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• v.9 no.4
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• pp.137-142
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• 2008

The parasitic resistance is studied to silicon/metal contact junction for improving device performance and to lower contact/serial resistance silicide in natural sequence. In this paper constructs the stepwise Ni silicide process for parasitic resistance reduction for silicon/metal contact junction. We have investigated multi-step Ni silicide on SiGe substrate with stepwise annealing method as an alternative to compose more thermally reliable Ni silicide layer. Stepwise annealing for silicide formation is exposed to heating environment with $5^{\circ}C/sec$ for 10 seconds and a dwelling for both 10 and 30 seconds, and ramping-up and the dwelling was repeated until the final annealing temperature of $700\;^{\circ}C$ is achieved. Finally a direct comparison for single step and stepwise annealing process is obtained for 20 nm nickel silicide through stepwise annealing is $5.64\;{\Omega}/square$ at $600\;^{\circ}C$, and it is 42 % lower than that of as nickel sputtered. The proposed stepwise annealing for Ni silicidation can provide the least amount of NiSi at the interface of nickel silicide and silicon, and it provides lower resistance, higher thermal-stability, and superior morphology than other thermal treatment.