• Korean Journal of Materials Research
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• v.2 no.1
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• pp.35-42
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• 1992

Thermal behavior of residue and damaged layer formed by reactive ion etching (RIE) in $CHF_3/C_2F_6$ were investigated using X-ray photoelectron spectroscopy(XPS) and secondary ion mass spec-trometry(SIMS) techniques. Decomposition of polymer residue film begins at $200^{\circ}C$ and above $400^{\circ}C$ carbon compound as graphite mainly forms by in-situ resistive heating. It reveals that thermal decomposition of residue can be completed by rapid thermal anneal treatment above $800^{\circ}C$ under nitrogen atmosphere and out-diffusion of carbon and fluorine of damaged layer is observed.

• Polymer(Korea)
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• v.27 no.2
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• pp.91-97
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• 2003

The effect of fluorination of nanoscaled silicas on mechanical interfacial properties and thermal stabilities of the silica/polyurethane composites was investigated. The surface properties of the silica were studied in X-ray photoelectron spectroscopy and contact angle measurements. Their mechanical interfacial properties and thermal stabilities of the composites were characterized by tearing energy and decomposition activation energy, respectively. As experimental results, the London dispersive component of surface free energy and fluorine functional groups of silica surfaces were increased as a function of fluorination temperature resulting in improving the trearing energy ($G_{IIIC}$) of the composites. Also, the thermal stabilities of the composites were increased as the treatment temperature increases. These results could be explained that the fluorine functional groups on silica surfaces played an important role in improving the intermolecular interactions at interfaces between silicas and polyurethane matrix in a composite system.

• Journal of Korean Ophthalmic Optics Society
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• v.13 no.3
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• pp.73-77
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• 2008

Purpose: This research is that prepare amorphous or crystalline ZnO thin films with pure strong UV emission on soda-lime-silica glass (SLSG) substrates by low-temperature annealing. Methods: Growth characteristic and optical properties of the amorphous or nano-crystalline ZnO thin films prepared on soda - lime - silica glass substrates by chemical solution deposition at 100, 150, 200, 250 and $300^{\circ}C$ were investigated using X-ray diffraction analysis, ultraviolet - visible - near infrared spectrophotometer, and photoluminescence. Results: The films exhibited an amorphous pattern even when finally annealed at $100^{\circ}C{\sim}200^{\circ}C$ for 60 min, while crystalline ZnO was obtained by prefiring at 250 and $300^{\circ}C$. The photoluminescence spectrum of amorphous ZnO films shows a strong NBE emission, while the visible emission is nearly quenched. Conclusions: These results indicate it should be possible to cheaply and easily fabricate ZnO-based optoelectronic devices at low temperature, below $200^{\circ}C$, in the future.

• Proceedings of the Korean Vacuum Society Conference
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• 2014.02a
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• pp.388.2-388.2
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• 2014

최근 그래핀 연구와 더불어 2차원 구조의 나노소재에 대한 관심이 급증하면서 육각형의 질화붕소(hexagonal boron nitride; h-BN) 박막(nanosheet) [1]이나 붕소 탄화질화물(boron caronitride; BCN) 박막 [2,3]와 같은 2차원 구조체에 대한 연구가 활발히 진행되고 있다. 그 중 BCN은 반금속(semimetal)인 흑연(graphite)과 절연체인 h-BN이 결합된 박막으로 원소의 구성 비율에 따라 전기적 특성을 제어할 수 있다는 장점이 있다. 따라서 다양한 나노소자로의 응용을 위한 연구가 활발히 진행되고 있다. 본 연구에서는 폴리스틸렌(polystyrene, PS)과 보레인 암모니아(borane ammonia)를 고체 소스로 이용하여 열화학기상증착법을 이용하여 BCN 박막를 SiO2 기판 위에 직접 합성하였다. SEM과 AFM 관측을 통해 합성된 BCN 박막을 확인하였으며, RMS roughness가 0.5~2.6 nm로 매우 낮은 것을 확인하였다. 합성과정에서 PS의 양을 조절하여 BCN 박막의 탄소의 밀도를 성공적으로 제어하였으며, 이에 따라 전기적인 특성이 제어되는 양상을 확인하였다. 또한 합성온도 변화에 따른 BCN 박막의 전기적인 특성이 제어되는 양상을 확인하였다. 추가적으로 같은 방법을 이용하여 BCN 박막을 Ni 위에서 합성하여 SiO2 기판위에 전사 하였다. 합성된 BCN 박막의 구조적 특징과 화학적 조성 및 결합 상태를 투과전자현미경(transmission electron microscopy), X-선 광전자 분광법(X-ray photoelectron spectroscopy)을 통해 조사하였다.

• Korean Journal of Materials Research
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• v.1 no.4
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• pp.214-220
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• 1991

The effects of $SiO_2$ reactive ion etching (RIE) in $CHF_{3/}C_2F_6$ on the surface properties of the underlying Si substrate were studied by X-ray photoelectron spectroscopy(XPS) and secondary ion mass spectrometry(SIMS) techniques. Angle-resolved XPS analysis was carried out as non-destructive depth profile one for investigating the chemical bonding states of silicion, carbon, oxygen and fluorine. The residue layer consists of C-F polymer. O-F bond was found on the top of the polymer layer and Si-O, Si-C and Si-F bonds were detected between Si substrate and polymer film. A 60nm thick damaged layer of silicon surface mainly contains carbon and fluorine.

• Journal of the Microelectronics and Packaging Society
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• v.29 no.2
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• pp.43-48
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• 2022

Effect of temperature/humidity (T/H) treatment conditions on the peel strength of screen-printed Ag/polyimide (PI) structures was evaluated by peeling PI films in 90° peel test. Initial peel strength was 25.99±1.47 gf/mm, and then decreased to 6.05±0.54 gf/mm after 500 h at 85℃/85% relative humidity T/H condition. And, the peeled locus was changed from Ag/PI interface to shallow cohesive inside PI near interface. X-ray photoelectron spectroscopy analysis on the peeled surfaces showed that the long-term moisture penetration into the Ag/PI interface during T/H treatment led to hydrolytic degradation of PI to form weak boundary layer inside PI near Ag/PI interface, which are responsible for large decrease in peel strength.

• The Journal of Korea Institute of Information, Electronics, and Communication Technology
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• v.17 no.3
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• pp.146-154
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• 2024

In this paper, we present a convenient liquid crystal (LC) molecular alignment method using brush hairs as an alternative to the rubbing process in the LC display industry. Titanium strontium yttrium zirconium oxide (TiSrYZrO) solution was prepared using a sol-gel process, and the TiSrYZrO alignment film production and LC molecular alignment were integrated through a one-step brush coating process. As the curing temperature increased, the LC molecule alignment of the LC cell improved, and the formation of a physical surface anisotropic structure due to the shear stress caused by the movement of the brush hairs on the coating surface led to uniform alignment of the LC molecules. Uniform and homogeneous LC molecular alignment was confirmed through polarizing optical microscopy and pretilt angle measurement. Through thermal oxidation using X-ray photoelectron spectroscopy, the TiSrYZrO thin film well formed of metal oxide was confirmed and verified to have excellent optical transparency. From these results, it is expected that a convenient LC molecular alignment method using brush hairs as an alternative to the rubbing process will be a viable next-generation technology.

• Journal of IKEEE
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• v.28 no.3
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• pp.261-270
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• 2024

In this study, a lanthanum gallium oxide (LaGaO) solution was prepared using a sol-gel method. By simply forming a LaGaO thin film through adjusting the curing temperature after applying the solution onto the substrate using a brush coating process, the potential for use as a liquid crystal (LC) alignment film in the LC display industry was validated. Through optical microscope observation, it was confirmed that the LC molecules were uniformly aligned as the curing temperature of the LaGaO thin film increased. It was confirmed that the LaGaO thin film cured at 230℃ had low pretilt angle, and that LaGaO particles were formed in a single direction as observed through an atomic force microscope. Through X-ray photoelectron spectroscopy, it was found that the LaGaO metal oxide thin film was well formed. Finally, it has been confirmed that LaGaO metal oxide has the potential as a novel LC alignment film material, as it exhibits excellent electrical and optical properties, along with high optical transmittance.

• Journal of the Microelectronics and Packaging Society
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• v.27 no.3
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• pp.41-47
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• 2020

The effect of Co interlayer on the interfacial reliability of SiN_x/Co/Cu thin film structure for advanced Cu interconnects was systematically evaluated by using a double cantilever beam test. The interfacial adhesion energy of the SiN_x/Cu thin film structure was 0.90 J/㎡. This value of the SiN_x/Co/Cu thin film structure increased to 9.59 J/㎡.Measured interfacial adhesion energy of SiN_x/Co/Cu structure was around 10 times higher than SiN_x/Cu structure due to CoSi₂ reaction layer formation at SiN_x/Co interface, which was confirmed by X-ray photoelectron spectroscopy analysis. The interfacial adhesion energy of SiN_x/Co/Cu structure decreased sharply after post-annealing at 200℃ for 24 h due to Co oxidation at SiN_x/Co interface. Therefore, it is required to control the CoO and Co₃O₄ formation during the environmental storage of the SiN_x/Co/Cu thin film to achieve interfacial reliability for advanced Cu interconnections.

• Applied Chemistry for Engineering
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• v.23 no.3
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• pp.313-319
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• 2012

In this work, the electroplating of copper was introduced on PAN-based carbon fibers for the enhancement of mechanical interfacial strength of carbon fibers-reinforced composites. The surface properties of carbon fibers were determined by scanning electron microscopy (SEM), X-ray photoelectron spectroscopy (XPS), X-ray diffraction (XRD), and contact angle measurements. Its mechanical interfacial properties of the composites were studied by interlaminar shear strength (ILSS) and critical stress intensity factor ($K_{IC}$). From the results, it was found that the mechanical interfacial properties of Cu-plated carbon fibers-reinforced composites (Cu-CFRPs) enhanced with increasing the Cu plating time, Cu content and COOH group up to Cu-CFRP-30. However, the mechanical interfacial properties of the Cu-CFRPs decreased dramatically in the excessively Cu-plated CFRPs sample. In conclusion, the presence of Cu particles on carbon fiber surfaces can be a key factor to determine the mechanical interfacial properties of the Cu-CFRPs, but the excessive Cu content can lead the failure due to the interfacial separation between fibers and matrices in this system.