• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2008.11a
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• pp.37-37
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• 2008

에어로졸데포지션법을 이용하여 집적화 기판을 위한 $Al_2O_3$-PMMA 복합체 후막을 상온에서 구리 기판 위 에 제조하였다. XRD, FT-IR 분석을 통해 코팅된 막은 $Al_2O_3$와 PMMA의 혼합물로 존재함을 확인하였으며 성막 중 $Al_2O_3$. PMMA의 상호작용과 PMMA 파우더의 거동에 대한 분석을 통해 $Al_2O_3$-PMMA 복할체 후막의 성막 양상을 확인할 수 있었다. 또한 기판 거칠기에 따라 초기 계면의 양상이 달라질 수 있음을 확인하였고 이러한 초기 계면의 상태가 $Al_2O_3$-PMMA 복합체 후막의 제조에 있어 매우 중요함을 알 수 있었다. 본 연구에서는 에어로졸데포지션법을 이용한 $Al_2O_3$-PMMA 복합체 후막의 성막 양상을 통해 세라믹-폴리머 복합체의 제조에 있어서의 주요 변수들을 알아보고 $Al_2O_3$-PMMA 복합체 후막의 전기적인 특성을 확인하였다.

• Journal of the Semiconductor & Display Technology
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• v.2 no.2
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• pp.5-8
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• 2003

In this study, as Cu diffusion barrier, tantalum nitrides were successfully deposited on Si(100) substrate and $SiO_2$ by plasma assisted atomic layer deposition(PAALD) and thermal ALD, using pentakis (ethylmethlyamino) tantalum (PEMAT) and NH$_3$ as precursors. The TaN films were deposited at $250^{\circ}C$ by both method. The growth rates of TaN films were 0.8${\AA}$/cycle for PAALD and 0.75${\AA}$/cycle for thermal ALD. TaN films by PAALD showed good surface morphology and excellent step coverage for the trench with an aspect ratio of h/w -1.8:0.12 mm but TaN films by thermal ALD showed bad step coverage for the same trench. The density for PAALD TaN was 11g/cmand one for thermal ALD TaN was 8.3g/$cm^3$. TaN films had 3 atomic % carbon impurity and 4 atomic % oxygen impurity for PAALD and 12 atomic % carbon impurity and 9 atomic % oxygen impurity for thermal ALD. The barrier failure for Cu(200 nm)/TaN(10 nm)/$SiO_2$(85 nm)/ Si structure was shown at temperature above $700^{\circ}C$ by XRD, Cu etch pit analysis.

• Proceedings of the International Microelectronics And Packaging Society Conference
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• 2003.11a
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• pp.181-184
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• 2003

Low Energy High flux Plasma Source인 Stationary Plasma thruster (SPT)를 이용하여 폴리이미드의 표면개질 후 접촉각과 표면에너지의 변화를 조사하고 접착력과의 관계를 조사하였다. 이온에너지는 180 eV - 200 eV, 이온전류 밀도는 수백 ${\mu}A/cm^2$, 이온선량은 $5\times10^{15}/cm^2$부터, $10\times^{18}/cm^2$로 $Ar^+,\;N_2^+,\;O_2^+$를 이온 주입시켰다. 표면 처리된 폴리이미드에 대한 접촉각 변화는 dual contact anglemeter로 증류수와 에틸렌글리콜을 이용하여 측정하였고, 표면에너지의 변화량을 구하였다. 접촉각의 변화는 아르곤 이온의 경우는 최저 $35^{\circ}$, 질소와 산소의 경우 $1\times10^{17}/cm^2$에서 각각 $14^{\circ},\;10^{\circ}$정도의 전촉각을 보였으며, $5\times10^{17}/cm^2$이상에서는 측정하기 불가능하였다. 산소 이온빔으로 처리된 PI의 표면을 x-ray photoelectron spectroscopy를 통하여 측정하여본 결과, 친수성기가 많이 형성되었음을 확인할 수 있었다. 접촉각 측정으르부터 PI의 표변에너지는 42.1 mN/m에서 아르곤 이온빔의 처리 시 65.2 mN/m로 산소 이온빔의 처리 시 81.2 mN/m로 각각 1.5배, 1.9배 정도 증대하였다. 산소 이온빔으로 처리된 PI 표면위에 스퍼터링으로 300 nm 정도의 clad layer 형성 후 $20{\mu}m$ 정도의 구리 전기 도금막을 형성하여, peel 강도를 측정한 결과 0.79 kg/cm의 강도를 얻을 수 있었다.

• Proceedings of the KIEE Conference
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• 2002.07c
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• pp.2000-2002
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• 2002

신장병의 조기진단을 위해서 체내의 요소 농도의 정확한 측정은 매우 중요하며, 이러한 이유에서 많은 연구자들은 보다 빠르고 정확한 체내의 요소농도 측정을 위한 바이오센서를 개발 중이다. 본 논문은 반도체 공정을 이용하여 산화막(4.000${\AA}$)이 성장된 p-형 실리콘 웨이퍼를 사용하였다. RF sputter를 사용하여 티타늄과 백금을 증착한 백금 박막전극을 제작하였다. 그 위에 전도성 고분자인 Polypyrrole(PPy)과 전도도를 증가시키기 위하여 구리를 도펀트로 사용 scan rate 40mV/S $0.8{\sim}-0.8V$ 전위영역에서 산화적 전기 중합법 (anodical electropolymerization)을 이용하여 전극을 형성하였다. 요소를 2개의 암모늄 이온과 1개의 탄산 이온으로의 가수분해반응을 촉매하는 효소로써 유레이즈(urease)를 전기적 흡착방법을 이용하여 고정화하고 이에 요소농도의 변화에 대하여 시간대 전류법 (chronoamperometry:CA)을 사용하여 감도를 측정하였다. 최적화된 조건하에서 요소농도에 비례하여 Cu-doped PPy electrode로부터 얻어진 확산한계전류는 $4.5{\mu}A$/decade의 기울기를 나타내었다. 전극의 표면은 SEM(Scanning Electron Microscopy)과 EDX(Energy Dispersive X-Ray Spectrometer)를 이용하여 분석 하였다.

• Proceedings of the Korean Society Of Semiconductor Equipment Technology
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• 2002.11a
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• pp.14-19
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• 2002

In this study, as Cu diffusion barrier, tantalum nitrides were successfully deposited on Si(100) substrate and SiO2 by plasma assisted atomic layer deposition(PAALD) and thermal ALD, using pentakis (ethylmethlyamino) tantalum (PEMAT) and $NH_3$ as precursors. The TaN films were deposited on $250^{\circ}$C by both method. The growth rates of TaN films were $0.8{\AA}$/cycle for PAALD and $0.75{\AA}$/cycle for thermal ALD. TaN films by PAALD showed good surface morphology and excellent step coverage for the trench with an aspect ratio of h/w - $1.8 : 0.12 \mu\textrm{m}$ but TaN films by thermal ALD showed bad step coverage for the same trench. The density for PAALD TaN was $11g/\textrm{cm}^3$ and one for thermal ALD TaN was $8.3g/\textrm{cm}^3$. TaN films had 3 atomic % carbon impurity and 4 atomic % oxygen impurity for PAALD and 12 atomic % carbon impurity and 9 atomic % oxygen impurity for thermal ALD. The barrier failure for Cu(200nm)/TaN(l0nm)/$SiO_2(85nm)$/Si structure was shown at temperature above $700^{\circ}$C by XRD, Cu etch pit analysis.

• Journal of the Microelectronics and Packaging Society
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• v.22 no.4
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• pp.57-63
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• 2015

In order to prepare a low-cost conductive filler material possessing improved anti-oxidation property, Ag-coated Cu flakes were fabricated and the effects of an applying method of ammonium-based pretreatment solution on the Cu flakes were analyzed. The pretreatment solution was used to remove the surface oxide layer on Cu flake. During a single-stage pretreatment process, hole-shaped defects were formed on the flake surface during the pretreatment after 2 min, and the number and size increased in proportion to the pretreatment time. In the case that Ag plating solution was injected in the pretreatment solution after the pretreatment for 2 min, the defects were also formed during Ag plating. In contrast, the defects tremendous decreased in the case that the pretreatment solution was removed after the first pretreatment for 2 min and the Ag plating proceeded after the second pretratment using a low concentration pretreatment solution. As the final result, the 15 wt% Ag-coated Cu flake sample which was fabricated using the single-stage pretreatment oxidized at $166^{\circ}C$, but the sample fabricated by the double-stage pretreatment oxidized at $224^{\circ}C$, indicating definitely improved anti-oxidation property.

• Membrane Journal
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• v.28 no.4
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• pp.252-259
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• 2018

An acidic, real metal-plating wastewater was treated by a fluidized bed membrane reactor introduced with granular activated carbon (GAC) as fluidized media. With GAC fluidization, there was no increase in suction pressure with time at each flux set-point applied. At neutral solution pH, much less fouling rate was observed than acidic pH under GAC fluidization. Higher solution pH resulted in the increase in particle size in metal-finishing wastewater, thus producing a less dense cake structure on membrane. More than 95% of chemical oxygen demand was observed from the fluidized bed membrane reactor under GAC fluidization. Total suspended solid concentration in membrane permeate was near zero. At the raw wastewater pH, no removal of copper and chromium by the fluidized bed membrane reactor was observed. As the pH was increased to 7.0, removal efficiency of copper and chromium was increased considerably to 99 and 94%, respectively. Regardless of solution pH tested, more than 95% of cyanide was removed possibly due to the strong adsorption of organic-cyanide complex on GAC in fluidized bed membrane reactor.

• Journal of the Korean Chemical Society
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• v.48 no.6
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• pp.590-598
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• 2004

The preconcentration and determination of trace Cu(II) and Pb(II) on calcium alginate beads in aqueous solution were studied. A calcium alginate beads were prepared by adding an alginic acid to sample solution contained Ca(II). Some following conditions were optimized: the pH of sample solution, amount of alginic acid, and stirring time for effective adsorption; the type and concentration of acid, and sonication time in an ultrasonic vibrator for the perfect de-sorption. A sample solution was prepared with Cu(II) and Pb(II) in DI water. And Ca(II) and ethanol was added into the sample solution. The pH of the final sample solution was controlled with buffer solution. The alginic acid were dispersed in the sample solution by a magnetic stirrer. This mixture was stored in room temperature for 30 min to form a calcium alginate. After the beads were filtered and washed on a membrane filter, the analytes were redissolved from the beads by an ultrasonic vibration of 10 minutes in 1.0M $HNO_3$ solution. The effect of diverse ions on the adsorption of analytes were studied. This procedure was applied for the analysis of two real samples. The recoveries in spiked samples were $90.4{\sim}104.3%$ for analytes.

• Journal of the Korean Chemical Society
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• v.41 no.4
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• pp.180-185
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• 1997

Zinc, cadmium, lead and copper were simultaneously determined by depositing metals at - 1.200 V vs. a Ag/AgCl(sat. KCl) reference electrode for 150 seconds on a hanging mercury drop electrode(HMDE) or a thin mercury film electrode(TMFE), followed by scanning towards anodic direction using differential pulse voltammetric(DPASV) and square wave voltammetric(SWASV) techniques. The linear calibration curves were obtained for four metal ions simultaneously determined by DPASV with a HMDE in the concentration range between 20 and 100 ppb. However, the linear calibration plots were obtained only for $Cd^{2+}$ and $Pb^{2+}$ in the simultaneous determinations with a TMFE in the concentration range up to 100 ppb using DPASV and up to 10 ppb using SWASV. DPASV with a TMFE was about 15 times more sensitive than DPASV with a HMDE for simultaneous determinations of $Cd^{2+}$ and $Pb^{2+}$. SWASV was about 5 times more sensitive than DPASV at a TMFE. Concentrations of zinc in seven different sediment samples determined by DPASV with a HMDE and inductively coupled plasma-mass spectrometry were compared, resulting with an excellent correlation coefficient of 0.9993 and with no significant difference between two methods after t-test.

• Nuclear Engineering and Technology
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• v.21 no.2
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• pp.111-122
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• 1989

With the Zircaloy-4 tube oxidized in high temperature (1323 K) steam for 5, 10, 30 and 60 minutes, the expanding copper mandrel test was carried out over a temperature range of 673-l173k at $\varepsilon\;=\;3.0\times10^5S\;^1$. The oxidation parameters $(K_i)$ in the present study were linearly proportional to square root of time $(Ki= \delta_{kit})$ and their rate constants ($\delta_{ki}$) are 0.281, 2.82, and 2.313 for weight gain and thickness of Zr02 and $\alpha$(0) layer, respectively. Activation energy for high temperature (873-1073k) plastic deformation of Zircaloy-4 increases from 251 KJ/mol to 323 KJ/mol with increase in oxidation time from 5 minutes to 60 minutes due to the high strengthened Zr02. With the oxide layer thickness [K ; expressed in "Equivalent Cladding Reacted" (ECR,%)] and the yield stress obtained from the mandrel test, an empirical relation was derived as ($\sigma/C)^n=K^mexp$ (Q/RT) with n=6.9, m=5.7, C=0.155, 0.138, 0.051, and 0.046 MPa for Q=251, 258, 316, 323 KJ/mol, respectively.