• Journal of the Institute of Electronics Engineers of Korea SD
• /
• v.44 no.12
• /
• pp.12-17
• /
• 2007

The effects of the evaporation rate of MgO films using an electron beam on the MgO properties and the discharge characteristics of a plasma display panel(PDP) were investigated and analyzed. Mgo films were deposited with the various MgO evaporation rates. The MgO properties such as the crystal orientation, the surface roughness, and the film structure, were inspected using XRD(X-ray diffractometry), AFM(atomic force microscopy). From the experiments and Paschen law, the maximum value of the secondary, electron emission coefficient $(\gamma)$ was obtained at the evaporation rate of $5\AA/sec$. The minimum firing voltage and the maximum luminous efficiency were obtained at an evaporation rate of $5\AA/sec$. In the MgO film deposited at $5\AA/sec$, the (200) orientation and $F^+$ center were most intensive. The XRD results and cathode-luminescence(CL) spectra show the $\gamma$ values are correlated with $F/F^+$ centers of the molecular structure of MgO films.

• Proceedings of the Korean Vacuum Society Conference
• /
• 2015.08a
• /
• pp.187-187
• /
• 2015

The past thirty years have seen increasingly rapid advances in the field of Indium Tin Oxide (ITO) transparent thin film.[1] However, a major problem with this ITO thin film application is high cost compared with other transparent thin film materials.[2] So far, in order to overcome this disadvantage, we show a transparent ITO/Ag/i-ZnO multilayer thin film electrode can be the solution. In comparison with using amount of ITO as a transparent conducting material, intrinsic-Zinc-Oxide (i-ZnO) based on ITO/Ag/i-ZnO multilayer thin film showed cost-effective and it has not only highly transparent but also conductive properties. The aim of this research has therefore been to try and establish how ITO/Ag/i-ZnO multilayer thin film would be more effective than ITO thin film. Herein, we report ITO/Ag/i-ZnO multilayer thin film properties by using optical spectroscopic method and measuring sheet resistance. At a certain total thickness of thin film, sheet resistance of ITO/Ag/i-ZnO multilayer was drastically decreased than ITO layer approximately $40{\Omega}/{\square}$ at same visible light transmittance.(minimal point $5.2{\Omega}/{\square}$). Tendency, which shows lowly sheet resistive in a certain transmittance, has been observed, hence, it should be suitable for transparent electrode device.

• Journal of Oriental Neuropsychiatry
• /
• v.18 no.1
• /
• pp.173-814
• /
• 2007

Objective : This Study is attempted to compare respiration training method on Sun-Do Training it is quadrivalence. Method : We used all books and paper, journal of inside and outside of the country on Sun-Do Training. Results and Conclusions: 1. Respiration training method on Mu-Eou-Do is spontaneous breathing, breath follows in individual’s respiratory. 2. Respiration training method on Suk-Mun, Guk-Seon-Do, Dan-Hak is all of the position differ, but all considers and breathes naturally abdominal region named Dan-Jeoun, the hypogastric center (丹田). 3. Respiration training method that intend in Guk-seon-do should be soft and slow and long and deep and the moment must not be stoppage. 4. Difference of respiration training method is that region that mean at practice differs. Suk-Mun and Guk-Seon-Do have respiration training method that do with anus as is special in practice process. Dan-Hak thinks that breath has entered as Myung-Mun(命門), means fundamental force.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
• /
• v.30 no.3
• /
• pp.162-169
• /
• 2017

Indium tin oxide (ITO) thin films show a low sheet resistance and high transmittance in the visible range of the spectrum. Therefore, they play an important role as transparent electrodes for flat panel displays. However, their resistivity is rather high for use as a transparent electrode in large displays. One way to improve electrical and optical properties in large displays is to use ITO/Ag/ITO multilayer films. ITO/Ag/ITO multilayer films have lower sheet resistance than single layer ITO films with the same thickness. Prior to the ITO/Ag/ITO multilayer experiments, optimal condition for thickness change are necessary. Their thicknesses were deposited differently in order to analyze electrical and optical properties. However, when optimal single film characteristics are applied to ITO/Ag/ITO multilayer films, other phenomena appeared. After analyzing the electrical and optical properties by changing ITO and Ag film thickness, ITO/Ag/ITO multilayer films were optimized. By combining ITO film at $586\;{\AA}$ and Ag film at 10 nm, the ITO/Ag/ITO multilayer films showed optimized high optical transmittance of 87.65%, and the low sheet resistance of $5.5{\Omega}/sq$.

• Journal of Electrical Engineering and Technology
• /
• v.9 no.6
• /
• pp.2070-2078
• /
• 2014

In this work, the frequency response of gate-all-around (GAA) Ge/GaAs heterojunction tunneling field-effect transistor (TFET) with hetero-gate-dielectric (HGD) and pnpn channel doping profile has been analysed by technology computer-aided design (TCAD) device-circuit mixed-mode simulations, with comparison studies among ppn, pnpn, and HGD pnpn TFET devices. By recursive tracing of voltage transfer curves (VTCs) of a common-source (CS) amplifier based on the HGD pnpn TFET, the operation point (Q-point) was obtained at $V_{DS}=1V$, where the maximum available output swing was acquired without waveform distortion. The slope of VTC of the amplifier was 9.21 V/V (19.4 dB), which mainly resulted from the ponderable direct-current (DC) characteristics of HGD pnpn TFET. Along with the DC performances, frequency response with a small-signal voltage of 10 mV has been closely investigated in terms of voltage gain ($A_v$), unit-gain frequency ($f_{unity}$), and cut-off frequency ($f_T$). The Ge/GaAs HGD pnpn TFET demonstrated $A_v=19.4dB$, $f_{unity}=10THz$, $f_T=0.487$ THz and $f_{max}=18THz$.

• JSTS:Journal of Semiconductor Technology and Science
• /
• v.15 no.2
• /
• pp.267-275
• /
• 2015

In this paper, ZnO films were prepared by atomic layer deposition (ALD) and CdS films were deposited using chemical bath deposition (CBD) to form ZnO/CdS heterojunction. More accurate mapping of band arrangement of the ZnO/CdS heterojunction has been performed by analyzing its electrical and optical characteristics in depth by various methods including transmittance, x-ray photoemission spectroscopy (XPS), and ultraviolet photoemission spectroscopy (UPS). The optical bandgap energies ($E_g$) of ZnO and CdS were 3.27 eV and 2.34 eV, respectively. UPS was capable of extracting the ionization potential energies (IPEs) of the materials, which turned out to be 8.69 eV and 7.30 eV, respectively. The electron affinity (EA) values of ZnO and CdS calculated from IPE and $E_g$ were 5.42 eV and 4.96 eV, respectively. Energy-band structures of the heterojunction could be accurately drawn from these parameters taking the conduction band offset (CBO) into account, which will substantially help acquisition of the full band structures of the thin films in the CIGS solar-cell device and contribute to the optimal device designs.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
• /
• v.26 no.1
• /
• pp.44-48
• /
• 2013

Niobium oxide($Nb_2O_5$) films were deposited on p-type Si wafers at room temperature using in-line pulsed-DC magnetron sputtering system with various frequencies. The different duty ratios were obtained by varying the frequency of pulsed DC power from 100 to 300 kHz at the fixed reverse time of $1.5{\mu}s$. From the thickness of the sputtered $NbO_x$ films, it was possible to obtain much higher deposition rate in case of pulsed-DC sputtering than RF sputtering. However, the similar leakage currents and structural characteristics were obtained from the metal-insulator-semiconductor(MIS) structure fabricated with the $NbO_x$ films and the x-ray photoelectron spectroscopy(XPS) results in spite of the different deposition rates. From the experimental results, the $NbO_x$ films sputtered by pulsed-DC sputtering are expected to be used in the fabrication process instead of RF sputtering.

• Journal of the Semiconductor & Display Technology
• /
• v.20 no.4
• /
• pp.157-160
• /
• 2021

As an insulator for a thin film transistor(TFT) and an encapsulation material of organic light emitting diode(OLED), aluminum oxide (Al₂O₃) has been widely studied using several technologies. Especially, in spite of low deposition rate, atomic layer deposition (ALD) has been used as a process method of Al₂O₃ because of its low process temperature and self-limiting reaction. In the Al₂O₃ deposition by ALD method, Ar Purge had some crucial effects on the film properties. After reaction gas is injected as a formation of pulse, an inert argon(Ar) purge gas is injected for gas desorption. Therefore, the process parameter of Ar purge gas has an influence on the ALD deposited film quality. In this study, Al₂O₃ was deposited on glass substrate at a different Ar purge time and its structural characteristics were investigated and analyzed. From the results, the growth rate of Al₂O₃ was decreased as the Ar purge time increases. The surface roughness was also reduced with increasing Ar purge time. In order to obtain the high quality Al₂O₃ film, it was known that Ar purge times longer than 15 sec was necessary resulting in the self-limiting reaction.

• Journal of the Semiconductor & Display Technology
• /
• v.21 no.1
• /
• pp.67-70
• /
• 2022

In order to prevent water vapor and oxygen permeation in the organic light emitting diodes (OLED), Al₂O₃ thin-film encapsulation (TFE) technology were investigated. Atomic layer deposition (ALD) method was used for making the Al₂O₃ TFE layer because it has superior barrier performance with advantages of excellent uniformity over large scales at relatively low deposition temperatures. In this study, the thickness of the Al₂O₃ layer was varied by controlling the numbers of the unit pulse cycle including Tri Methyl Aluminum(Al(CH₃)₃) injection, Ar purge, and H₂O injection. In this case, several process parameters such as injection pulse times, Ar flow rate, precursor temperature, and substrate temperatures were fixed for analysis of the effect only on the thickness of the Al₂O₃ layer. As results, at least the thickness of 39 nm was required in order to obtain the minimum WVTR of 9.04 mg/m²day per one Al₂O₃ layer and a good transmittance of 90.94 % at 550 nm wavelength.

• Journal of the Semiconductor & Display Technology
• /
• v.22 no.1
• /
• pp.23-27
• /
• 2023

Organic light-emitting diode(OLED) is very thin organic films which are hundreds of nanometers. Unlike bottom-emission OLED(BEOLED), top-emission OLED(TEOLED) emits light out the front, opaque moisture absorbents or metal foils can't be used to prevent moisture and oxygen. And it is difficult to have flexible characteristics with glass encapsulation, so thin film encapsulation which can compensate for those two disadvantages is mainly used. In this study, Al₂O₃ thin films by atomic layer deposition(ALD) were examined by changing the argon gas purge flow rate and we applied this Al₂O₃ thin films to the encapsulation of TEOLED. Ag / ITO / N,N'-Di-[(1-naphthyl)-N,N'-diphenyl]-1,1'-biphenyl-4,4'-diamine / tris-(8-hydroxyquinoline) aluminum/ LiF / Mg:Ag (1:9) were used to fabricate OLED device. The characteristics such as brightness, current density, and power efficiency are compared. And it was confirmed that with a thickness of 40 nm Al₂O₃ thin film encapsulation process did not affect OLED properties. And it was enough to maintain a proper OLED operation for about 9 hours.