• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2008.11a
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• pp.324-325
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• 2008

In this Study, We fabricated a plasma discharge cluster with external electrodes which can be applied to flexible backlight in a polymer substrate and investigated the discharge characteristics. The Sealing process was progressed in vacuum chamber, which enable to fabricate plasma discharge cluster. The results of discharge characteristics show that the static memory margin of plasma discharge cluster was increased, as Ne/Xe(5%) gas pressure was increased. also, When gas pressure was 100torr at 600um of electrode gap, we have obtained high luminance of a plasma discharge cluster.

• Proceedings of the Korean Vacuum Society Conference
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• 2012.02a
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• pp.96-97
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• 2012

In nitride and oxide film deposition, sputtered metals react with nitrogen or oxygen gas in a vacuum chamber to form metal nitride or oxide films on a substrate. The physical properties of sputtered films (metals, oxides, and nitrides) are strongly influenced by magnetron plasma density during the deposition process. Typical target power densities on the magnetron during the deposition process are ~ (5-30) W/cm2, which gives a relatively low plasma density. The main challenge in reactive sputtering is the ability to generate a stable, arc free discharge at high plasma densities. Arcs occur due to formation of an insulating layer on the target surface caused by the re-deposition effect. One current method of generating an arc free discharge is to use the commercially available Pinnacle Plus+ Pulsed DC plasma generator manufactured by Advanced Energy Inc. This plasma generator uses a positive voltage pulse between negative pulses to attract electrons and discharge the target surface, thus preventing arc formation. However, this method can only generate low density plasma and therefore cannot allow full control of film properties. Also, after long runs ~ (1-3) hours, depends on duty cycle the stability of the reactive process is reduced due to increased probability of arc formation. Between 1995 and 1999, a new way of magnetron sputtering called HIPIMS (highly ionized pulse impulse magnetron sputtering) was developed. The main idea of this approach is to apply short ${\sim}(50-100){\mu}s$ high power pulses with a target power densities during the pulse between ~ (1-3) kW/cm2. These high power pulses generate high-density magnetron plasma that can significantly improve and control film properties. From the beginning, HIPIMS method has been applied to reactive sputtering processes for deposition of conductive and nonconductive films. However, commercially available HIPIMS plasma generators have not been able to create a stable, arc-free discharge in most reactive magnetron sputtering processes. HIPIMS plasma generators have been successfully used in reactive sputtering of nitrides for hard coating applications and for Al2O3 films. But until now there has been no HIPIMS data presented on reactive sputtering in cluster tools for semiconductors and MEMs applications. In this presentation, a new method of generating an arc free discharge for reactive HIPIMS using the new Cyprium plasma generator from Zpulser LLC will be introduced. Data (or evidence) will be presented showing that arc formation in reactive HIPIMS can be controlled without applying a positive voltage pulse between high power pulses. Arc-free reactive HIPIMS processes for sputtering AlN, TiO2, TiN and Si3N4 on the Applied Materials ENDURA 200 mm cluster tool will be presented. A direct comparison of the properties of films sputtered with the Advanced Energy Pinnacle Plus + plasma generator and the Zpulser Cyprium plasma generator will be presented.

• Proceedings of KOSOMES biannual meeting
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• 2018.06a
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• pp.201-201
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• 2018

• Journal of the Korean Chemical Society
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• v.34 no.5
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• pp.396-403
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• 1990

We describe how to design and construct a LPCVD (Low Pressure Chemical Vapor Deposition) apparatus which can be applicable to the study of reaction mechanism in general CVD experiments. With this apparatus we have attempted to make diamond like carbon films on the p-type (111) Si wafer from (H$_2$ ＋ CH$_4$) gas mixtures. Two different methods have been tried to get products. (1)The experiment was carried out in the reactor with two different inlet gas tubes. One coated with phosphoric acid was used for supplying microwave discharged hydrogen gas stream, and methane has been passed through the other tube without the microwave discharge. In this method we got only amorphous carbon cluster products. (2) The gas mixture (H$_2$ ＋ CH$_4$) has been passed through the discharge tube with the Si wafer located in and/or near the microwave plasma. In this case diamond-like carbon products could be obtained.

• Transactions on Electrical and Electronic Materials
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• v.12 no.5
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• pp.189-192
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• 2011

A flexible back-light unit (FBLU) is fabricated by embedding plasma discharge clusters in a flexible polymer matrix. The brightness uniformity of an FBLU was measured for various combinations of optical sheets and compared with the simulated results for various bending angles. A gap between light sources causes distinctive integrated brightness curves which have two inflection points depending on bending angle. The brightness distribution of a simulated BLU was in good agreement with that of an actual plasma BLU except for a dark area that appeared at the center of the simulated BLU. The real and simulated BLUs both clearly showed an angle dependency caused by mirror images located between point light sources. On the basis of these results, it is suggested that these mirror-like images could be a major factor in determining the characteristics of FBLUs.

• 한국정보디스플레이학회:학술대회논문집
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• 2007.08a
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• pp.224-227
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• 2007

The reconstruction characteristics of MgO (111) textured protective layer by over-frequency accelerated discharge in AC-PDP were investigated and correlated to the variations of electronic structures. The reconstruction process and exaggerated grain growth (EGG) were explained by defect-assisted 2-D nucleation and growth mechanism combined with charged cluster model.

• 한국정보디스플레이학회:학술대회논문집
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• 2008.10a
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• pp.957-960
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• 2008

The influences of silicon and MgO seed particle on the reconstruction characteristics of MgO protective layer were investigated to clarify the mechanism of reconstruction and exaggerated grain growth (EGG) in AC-PDP. The reconstruction and EGG are closely correlated with the driving force for nucleation and growth, interface energy and initial size distribution of MgO protective layer in plasma space during discharge in AC-PDP.

• Proceedings of the Korean Institute of Surface Engineering Conference
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• 2016.11a
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• pp.181-181
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• 2016

Hydrogenated microcrystalline silicon (${\mu}c-Si:H$) films have attracted much attention as materials of the bottom-cells in Si thin film tandem photovoltaics due to their low bandgap and excellent stability against light soaking. However, in PECVD, the source gas $SiH_4$ must be highly diluted by $H_2$, which eventually results in low deposition rate. Moreover, it is known that high-rate ${\mu}c-Si:H$ growth is usually accompanied by a large number of dangling-bond (DB) defects in the resulting films, which act as recombination centers for photoexcited carriers, leading to a deterioration in the device performance. During film deposition, Si nanoparticles generated in $SiH_4$ discharges can be incorporated into films, and such incorporation may have effects on film properties depending on the size, structure, and volume fraction of nanoparticles incorporated into films. Here we report experimental results on the effects of nonoparticles incorporation at the different substrate temperature studied using a multi-hollow discharge plasma CVD method in which such incorporation can be significantly suppressed in upstream region by setting the gas flow velocity high enough to drive nanoparticles toward the downstream region. All experiments were performed with the multi-hollow discharge plasma CVD reactor at RT, 100, and $250^{\circ}C$, respectively. The gas flow rate ratio of $SiH_4$ to $H_2$ was 0.997. The total gas pressure P was kept at 2 Torr. The discharge frequency and power were 60 MHz, 180 W, respectively. Crystallinity Xc of resulting films was evaluated using Raman spectra. The defect densities of the films were measured with electron spin resonance (ESR). The defect density of fims deposited in the downstream region (with nonoparticles) is higher defect density than that in the upstream region (without nanoparticles) at low substrate temperature of RT and $100^{\circ}C$. This result indicates that nanoparticle incorporation can change considerably their film properties depending on the substrate temperature.