• Proceedings of the KIEE Conference
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• 2006.07c
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• pp.1380-1381
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• 2006

본 연구는 MgO 박막을 유도 결합 플라즈마를 이용하여, $CF_4/Ar$ 가스 혼합비로 식각하였고, RF 전력, DC-bais 전압과 Process Pressure를 변경하면서 실험하였다. 빛 방출 분석(optical emission spectroscopy, OES)을 이용하여, 플라즈마 진단과 식각 특성과의 관계를 분석하였다. OES 결과로부터 $CF_4$ 첨가비를 50%까지는 증가시킴에 따라 식각률이 증가하였고, 그 후에 Ar 이온이 감소함으로써 식각률이 감소하였다. MgO 박막의 최고 식각률은 50%의 $CF_4/(CF_{4}+Ar)$에서 700 W의 RF 전력, -150 V의 DC-bias 전압, 반응로 압력은 15 mTorr, 기판 온도는 $30^{\circ}C$로 고정시켰을 때 29nm/min이었다. 이 조건에서 MgO 박막과 $SiO_2$의 선택비는 0.06 이었다.

• Journal of the Semiconductor & Display Technology
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• v.20 no.3
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• pp.22-26
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• 2021

Thin-film encapsulation (TFE) technology is most effective in preventing water vapor and oxygen permeation in the organic light emitting diodes (OLED). Of those, a laminated structure of Al₂O₃ and MgO were applied to provide efficient barrier performance for increasing the stability of devices in air. Atomic layer deposition (ALD) method is known as the most promising technology for making the laminated Al₂O₃/MgO and is used to realize a thin film encapsulation technology in organic light-emitting diodes. Atomic layer deposited inorganic films have superior barrier performance and have advantages of excellent uniformity over large scales at relatively low deposition temperatures. In this study, the control system of the MgCP₂ precursor for the atomic layer deposition of MgO was established in order to deposit the MgO layer stably by the injection time of second level and the stable heating temperature. The deposition rate was obtained stably to be from 4 to 10 Å/cycle using the injection pulse times ranging from 3 to 12 sec and a substrate temperature ranging from 80 to 150 ℃.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2001.11b
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• pp.73-76
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• 2001

We deposited epitaxial $Ba_{0.6}Sr_{0.4}TiO_{3}(BST)$ films having thickness of 400 nm on MgO(001) substrates, where a 10 nm thick $Ba_{1-x}Sr_{x}TiO_{3}$ (x = 0.1 - 0.7) interlayer was inserted between BST and MgO to manipulate the stress of the BST films. Since the main difference of those epitaxial BST films was the lattice constant of the interlayers, we were very successful in controlling the stress of the BST films. BST films under small tensile stress showed larger dielectric constant than that without stress as well as those under compressive stress. Stress relaxation was investigated using epitaxial BST films with various thicknesses grown on different interlayers. For BST films grown on $Ba_{0.7}Sr_{0.3}TiO_{3}$ interlayers, the critical thickness was about 600 nm. On the other hand, the critical thickness of single-layer BST film was less than 100 nm.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2001.11a
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• pp.73-76
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• 2001

We deposited epitaxial $Ba_{0.6}$S $r_{0.4}$Ti $O_3$(BST) films having thickness of 400 nm on MgO(001) substrates, where a 10 nm thick $Ba_{1-x}$S $r_{x}$Ti $O_3$(x=0.1-0.7) interlayer was inserted between BST and MgO to manipulate the stress of the BST films. Since the main difference of those epitaxial BST films was the lattice constant of the interlayers, we were very successful in controlling the stress of the BST films. BST films under small tensile stress showed larger dielectric constant than that without stress as well as those under compressive stress. Stress relaxation was investigated using epitaxial BST films with various thicknesses grown on different interlayers. For BST films grown on $Ba_{0.7}$S $r_{0.3}$Ti $O_3$ interlayers, the critical thickness was about 600 nm. On the other hand, the critical thickness of single-layer BST film was less than 100 nm.00 nm.m.m.m.

• Journal of the Korean Vacuum Society
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• v.8 no.1
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• pp.70-74
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• 1999

MgO-CaO protective layers with various composition were prepared by electron beam evaporation to improve the characteristics of conventional pure MgO thin films as a protective layer for AC-PDP. The maximum deposition rate of pure MgO was 1025 $\AA$/min and decreased with increasing [(CaO/(MgO+CaO)] ratio of evaporation starting materials. From XRD analyses, a trend of peak shift to the lower 2$\theta$ angle side was shown as CaO content increased and it stoped when the concentration of CaO was 0.13, which corresponds to the maximum solubility of CaO in MgO. The optimum composition of the protective thin films was Mg 47.1 at%, Ca 1.3 at%, O 51.6 at%, and firing voltage, memory margin and deposition rate of the film with this composition was 176 V, 0.5 and 515 $\AA$/min, respectively.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2001.07a
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• pp.263-266
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• 2001

In this paper, we investigated dielectric properies for BST thin films that was deposited on MgO/Si substrates using RF magnetron sputtering. In here, MgO film was used to perform that a diffusion b arrier between the BST film and Si substrate and a buffer layer to assist the BST film growth. A d eposition condition for MgO films was RF Power of 50W, substrate temperature of room temperature and the working gas ratio of Ar:O$_2$ were varied from 90:10 to 60:47. Finally we manufactured the cap acitor of Al/BST/MgO/Si/Al structure to know electrical properties of this capacitor through I-V, C-V measurement. In the results, C-V aha racteristic curves was shown a ferroelectric property so we measured P-E. A remanent poliazation and coerceive electric field was present 2$\mu$C/cm$^2$ and -27kV/cm respectively at Ar:O$_2$=90:10. And a va clue of dielectric constant was 86 at Ar:02=90:10.

• Proceedings of the KIEE Conference
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• 2000.07c
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• pp.2032-2034
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• 2000

The performance of ac plasma display panels (PDP) is influenced strongly by the surface glow discharge characteristics on the MgO thin films. This paper deals with the surface slew discharge characteristics and some physical properties of MgO thin films prepared by reactive RF planar unbalanced magnetron sputtering in connection with ac PDP. The samples prepared with the do bias voltage of -10V showed lower discharge voltage and lower erosion rate by ion bombardment than those samples prepared by conventional magnetron sputtering or E-beam evaporation. The main factor that improves the discharge characteristics by bias voltage is considered to be due to the morphology changes or crystal structure of the MgO thin film by ion bombardment during deposition process.

• Journal of the Korean Ceramic Society
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• v.28 no.3
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• pp.243-251
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• 1991

High-Tc YBa2Cu3O7-x superconducting thin films have been prepared by single-target off-axis RF magnetron sputtering. Optimal ratio of Y : Ba : Cu of the single-target was determined as 1 : 1.65 : 3.35 in order to obtain the stoichiometric films. Tc, crystalline phase, and microstructures of the surface and cross-section of the ex-situ YBa2Cu3O7-x thin films on MgO(100) had a Tc, zero of 80K, and the films on LaAlO3/Si had a Tc, on-set of 90 K and a Tc, zero of 70 K.

• Journal of the Korean institute of surface engineering
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• v.37 no.3
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• pp.169-174
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• 2004

MgO thin films were reactively deposited using an internal inductively coupled plasma assisted sputtering method varying reactive gas ratio to get stoichiometric film composition, and bipolar dc substrate bias to suppress micro arcs. The minimum frequency required for arc suppression was about 10KHz depending on ICP power. Their crystallinity was analyzed using X-ray diffraction and surface morphology using AFM. The surface was very smooth with rms roughness less than 0.42nm. The preferred orientation of the films were changing from (200) to bulk-like characteristics as Ar: $O_2$ratio was controlled to 10 : 2. Optical emission spectroscopy revealed that there were two distinct discharge modes: a blue one and a green one, where enhanced emission from Ar and Mg were observed. This cannot simply be understood by metallic or oxide mode of reactive sputtering due to ICP coupled to magnetron discharge.

• Korean Journal of Materials Research
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• v.9 no.6
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• pp.547-550
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• 1999

Optical and electrical properties of MgO-CaO films as a protective layer for AC plasma display panel were studied. When the [(CaO/(MgO+CaO)] ratio of evaporation starting materials was optimum composition, 0.1, firing voltage and memory margin of the film were 176V and 0.5, respectively. When [CaO/(CaO+MgO)] was 0, 0.1 and 0.2, memory margin was 0.39, 0.5 and 0.41, respectively, and surface roughness of films was $27.7\AA$, $21.1\AA$ and $40.3\AA$, respectively. It was thought that memory margin had a reverse-relation with surface roughness. The density of film was calculated by measuring the refractive index of film. The density of MgO film was 3.21g/㎤ and the density of film, when [CaO/(CaO+MgO)] was 0.1, was 3.632g/㎤. The mixture of MgO-CaO films showed a good transmittance property in the visual range.