• Applied Science and Convergence Technology
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• v.24 no.4
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• pp.90-95
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• 2015

The adsorption behavior of tris (dimethylamino)-cyclopentadienyl-zirconium (Cp-Zr) precursor using an in-situ attenuated total reflectance-Fourier transform infrared spectroscopy (ATR-FT-IR) was studied. In attempt to improve the detection intensity of an adsorbed precursor, nanoparticles were uniformly distributed on the Ge ATR crystal surface employing the spray method. The absorption characteristics studies were carried out over the Ge crystal temperature in the range of $30{\sim}50^{\circ}C$. Upon increasing the temperature, a reduction of absorption was observed. Based on the peak intensities of ATR-FT-IR spectroscopy, higher-$ZrO_2$ absorption efficiency occurs when the nano-particles are utilized compared to pure Ge crystal.

• Korean Journal of Agricultural Science
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• v.50 no.4
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• pp.675-696
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• 2023

Terpenoids, also referred to as terpenes, are a large family of naturally occurring chemical compounds present in the essential oils extracted from medicinal plants. In this study, a nondestructive methodology was created by combining ATR-FT-IR (attenuated total reflectance-Fourier transform infrared), and Raman spectroscopy for the terpenoids assessment in medicinal plants essential oils from ten different geographical locations. Partial least squares regression (PLSR) and support vector regression (SVR) were used as machine learning methodologies. However, a deep learning based model called as one-dimensional convolutional neural network (1D CNN) were also developed for models comparison. With a correlation coefficient (R²) of 0.999 and a lowest RMSEP (root mean squared error of prediction) of 0.006% for the prediction datasets, the SVR model created for FT-IR spectral data outperformed both the PLSR and 1 D CNN models. On the other hand, for the classification of essential oils derived from plants collected from various geographical regions, the created SVM (support vector machine) classification model for Raman spectroscopic data obtained an overall classification accuracy of 0.997% which was superior than the FT-IR (0.986%) data. Based on the results we propose that FT-IR spectroscopy, when coupled with the SVR model, has a significant potential for the non-destructive identification of terpenoids in essential oils compared with destructive chemical analysis methods.

• Proceedings of the Korean Vacuum Society Conference
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• 2013.08a
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• pp.120.2-120.2
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• 2013

반도체 소자의 소형화로 신개념 화학증착공정 구현을 위한 장비와 화학증착소재의 개발이 활발이 연구되고 있다. 특히 증착소재의 물리적 화학적 특성을 파악하고 가장 적합한 소재를 선택하기 위한 연구도 변행되고 있다. 많은 연구자들이 소재 평가를 위해 가스크로마토그래피, 질량분석기, 적외선 분광기 등을 이용한 화학증착소재의 특성을 파악하기 위해 노력하고 있다. 하지만 실제 화학기상증착(Chemical Vapor Deposition)법과 원자층증착(Atomic Layer Deposition)법 공정에서 웨이퍼 표면에서의 화학증착소재의 흡착거동에 대한 연구는 거의 전무한 실정이다. 따라서 본 연구에서는 개선된 Attenuated Total Reflectance(ATR)분광계를 이용하여 표면에 흡착된 소재의 흡착거동에 대해 분석을 수행하였다. 평가에 사용된 화학증착소재는 C-Zr (Tris (dimethylamino) cyclopentadienyl zirconium)이며, Fourier Transform Infrared Spectroscopy (FT- IR)시스템 내에 설치된 ATR 분광계 표면에 흡착된 C-Zr 증착소재를 다양한 공정조건(온도 및 반응가스, 플라즈마 파워 등)에서의 거동 변화를 연구하였다.

• Proceedings of the Korean Vacuum Society Conference
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• 2015.08a
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• pp.100.2-100.2
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• 2015

반도체 산업이 성장하고 기술이 향상됨에 따라 소자의 소형화가 이루어지고 있다. 공정법으로는 atomic layer deposition (ALD), chemical vapor deposition (CVD) 등이 있다. 이러한 공정을 이용하여 수십 nm까지 미세화가 진행되고 있으며, 복잡한 구조의 박막을 실현하기 위해 전구체의 개발이 활발히 진행되고 있다. 전구체의 특성을 비실시간으로 분석하는 방법으로는 질량 분석법, 가스크로마토그래피, 적외선 분광법 등이 있다. 전구체의 특성을 실시간으로 분석하기 위해 Fourier transform infrared spectroscopy (FTIR)내에 attenuated total reflectance (ATR)를 거치시켰다. 본 연구는 구조를 개선한 ATR-FTIR을 이용하여 Tris-(dimethylamino) Zirconium (CpZr) 전구체의 흡착 거동을 분석하였다. ATR용 crystal은 Ge crystal을 사용했으며, 온도를 각각 30, 40, $50^{\circ}C$에서 CpZr 전구체의 흡착특성을 연구했다. 흡착성을 증가시키기 위해 Ge crystal 표면에 $ZrO_2$나노입자를 분포시켜 흡착특성을 비교 분석하였다. 또한 CpZr 전구체가 흡착된 Ge crystal 표면에 오존가스를 주입시킨 후 변화를 관찰하였다. Ge crystal표면에 나노입자를 분포시켜 CpZr 전구체를 흡착한 결과 나노입자를 분포시키지 않았을 때 보다 흡착강도가 높게 나타났다. 또한 CpZr 전구체가 흡착된 Ge crystal 표면에 오존가스를 주입한 결과 C-H 결합이 분해됨을 확인했다.

• Membrane and Water Treatment
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• v.4 no.2
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• pp.109-126
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• 2013

Surface modification by low-pressure ammonia ($NH_3$) plasma on commercial thin-film composite (TFC) membranes was investigated in this study. Surface hydrophilicity, total surface free energy, ion exchange capacity (IEC) and zeta (${\zeta}$)-potentials were determined for the TFC membranes. Qualitative and quantitative analyses of the membrane surface chemistry were conducted by attenuated total reflectance Fourier transform infrared (ATR FT-IR) spectroscopy. Results showed that the $NH_3$ plasma treatment increased the surface hydrophilicity, in particular at a plasma treatment time longer than 5 min at 50 W of plasma power. Total surface free energy was influenced by the basic polar components introduced by the $NH_3$ plasma, and isoelectric point (IEP) was shifted to higher pH region after the modification. A ten (10) min $NH_3$ plasma treatment at 90 W was found to be adequate for the TFC membrane modification, resulting in a membrane with better characteristics than the TFC membranes without the modification for water treatment. The thin-film chemistry (i.e., fully-aromatic and semi-aromatic nature in the interfacial polymerization) influenced the initial stage of plasma modification.