• 한국재료학회지
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• 제21권2호
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• pp.89-94
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• 2011

In this work, fabrication and electrochemical analysis of an individual multi-walled carbon nanotube (MWNT) electrode are carried out to confirm the applicability of electrochemical sensing. The reactive ion etching (RIE) process is performed to obtain sensitive MWNT electrodes. In order to characterize the electrochemical properties, an individual MWNT is cut by RIE under oxygen atmosphere into two segments with a small gap: one segment is applied to the working electrode and the other is used as a counter electrode. Electrical contacts are provided by nanolithography to the two MWNT electrodes. Dopamine is specially selected as an analytical molecule for electrochemical detection using the MWNT electrode. Using a quasi-Ag/AgCl reference electrode, which was fabricated by us, the nanoelectrodes are subjected to cyclic voltammetry inside a $2{\mu}L$ droplet of dopamine solution. In the experiment, RIE power is found to be a more effective parameter to cut an individual MWNT and to generate "broken" open state, which shows good electrochemical performance, at the end of the MWNT segments. It is found that the pico-molar level concentration of analytical molecules can be determined by an MWNT electrode. We believe that the MWNT electrode fabricated and treated by RIE has the potential for use in high-sensitivity electrochemical measurement and that the proposed scheme can contribute to device miniaturization.

• 한국재료학회지
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• 제17권12호
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• pp.642-647
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• 2007

We investigated dry etching of acrylic (PMMA) in $O_2/N_2$ plasmas using a multi-layers electrode reactive ion etching (RIE) system. The multi-layers electrode RIE system had an electrode (or a chuck) consisted of 4 individual layers in a series. The diameter of the electrodes was 150 mm. The etch process parameters we studied were both applied RIE chuck power on the electrodes and % $O_2$ composition in the $N_2/O_2$ plasma mixtures. In details, the RIE chuck power was changed from 75 to 200 W.% $O_2$ in the plasmas was varied from 0 to 100% at the fixed total gas flow rates of 20 sccm. The etch results of acrylic in the multilayers electrode RIE system were characterized in terms of negatively induced dc bias on the electrode, etch rates and RMS surface roughness. Etch rate of acrylic was increased more than twice from about $0.2{\mu}m/min$ to over $0.4{\mu}m/min$ when RIE chuck power was changed from 75 to 200 W. 1 sigma uniformity of etch rate variation of acrylic on the 4 layers electrode was slightly increased from 2.3 to 3.2% when RIE chuck power was changed from 75 to 200 W at the fixed etch condition of 16 sccm $O_2/4\;sccm\;N_2$ gas flow and 100 mTorr chamber pressure. Surface morphology was also investigated using both a surface profilometry and scanning electron microscopy (SEM). The RMS roughness of etched acrylic surface was strongly affected by % $O_2$ composition in the $O_2/N_2$ plasmas. However, RIE chuck power changes hardly affected the roughness results in the range of 75-200 W. During etching experiment, Optical Emission Spectroscopy (OES) data was taken and we found both $N_2$ peak (354.27 nm) and $O_2$ peak (777.54 nm). The preliminarily overall results showed that the multi-layers electrode concept could be successfully utilized for high volume reactive ion etching of acrylic in the future.

• 한국전기전자재료학회논문지
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• 제17권3호
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• pp.299-304
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• 2004

In recent years, silicon carbide has emerged as an important material for MEMS application. In order to fabricate an SiC film based MEMS structure by using chemical etching method, high operating temperature is required due to high chemical stability Therefore, dry etching using plasma is the best solution. SiC film was deposited by thermal CVD at the temperature of 100$0^{\circ}C$ and pressure of 10 torr. SiC was dry etched with a reactive ion etching (RIE) system, using SF$_{6}$/O$_2$ and CF$_4$/O$_2$ gas mixture. Etch rate has been investigated as a function of oxygen concentration in the gas mixture, rf power, working pressure and gas flow rate. Etch rate was measured by surface profiler and FE-SEM. SF$_{6}$/O$_2$ gas mixture showed higher etch rate than CF$_4$/O$_2$ gas mixture. Maximum etch rate appeared at RF Power of 450W. $O_2$ dilute mixtures resulted in an increasing of etch rate up to 40％, and the superior anisotropic cross section was observe

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 2003년도 하계학술대회 논문집 Vol.4 No.2
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• pp.868-871
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• 2003

In recent years, silicon carbide has emerged as an important material for MEMS application. In order to fabricate an SiC film based MEMS structure by using chemical etching method, high operating temperature is required due to high chemical stability. Therefore, dry etching using plasma is the best solution. SiC film was deposited by thermal CVD at the temperature of $1000^{\circ}C$ and pressure of 10 torr. SiC was dry etched with a reactive ion etching (RIE) system, using $SF_6/O_2$ and $CF_4/O_2$ gas mixture. Etch rate have been investigated as a function of oxygen concentration in the gas mixture, RF power, and working pressure. Etch rate was measured by surface profiler and FE-SEM. $SF_6/O_2$ gas mixture has been shown high etch rate than $CF_4/O_2$ gas mixture. Maximum etch rate appeared at 450W of RF power. $O_2$ dilute mixtures resulted in an increasing of etch rate up to 40%, and the superior anisotropic cross section was observed.

• 한국진공학회지
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• 제1권1호
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• pp.145-152
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• 1992

Si surfaces exposed to CHF3/C2F6 gas plasmas ih reactive ion etching (RIE) have been characterized by X-ray photoelectron spectroscopy (XPS). CHF3/C2F6 gas plasma exposure of Si surface leads to the deposition of residual film containing carbon and fluorine. The narrow scan spectra of C 1s show various bonding states of carbon as C-Si, C-F/H, C-CFx(x $\leq$ 3), C-F, C-F2, and C-F3. The chemical bonding states of fluorine are described with F-Si, F-C and F-O. And the oxygen and silicon are also detected. The effects of parameters for reactive ion etching as CHF3/C2F6 gas ratio, RF power, and pressure are investigated.

• 한국정보통신학회:학술대회논문집
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• 한국해양정보통신학회 2005년도 추계종합학술대회
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• pp.389-392
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• 2005

차세대 반도체 공정을 위한 많은 노력 중 Reactive Ion Etching(RIE)에 대한 연구의 중요성은 계속되고 있으며, 현재 제조공정 라인에서는 공정상의 오류를 줄이는 노력에 주목 하고 있다. 본 논문에서는 이러한 점을 고려하여 반도체 제조 장비에서 발생하는 실시간 데이터에 대해 신경망을 이용하여 각 장비파라미터의 허용범위를 검출하고, 제안된 방법의 성능평가를 위하여, 생산라인에서 수립된 데이터를 활용하였다. 기존의 통계적 공정제어(SPC) 제서 지시되는 방법이 아닌 신경망 모델을 통하여 random variability를 고려한 control limit을 제시한다.

• 대한전기학회논문지:전기물성ㆍ응용부문C
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• 제52권11호
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• pp.496-500
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• 2003

A low-cost, large area, random, maskless texturing scheme independent of crystal orientation is expected to significantly impact terrestrial photovoltaic technology. We investigated silicon surface microstructures formed by reactive ion etching (RIE) in Multi-Hollow cathode system. Desirable texturing effect has been achieved when radio-frequency (rf) power of about 20 Watt per one hollow cathode glow is applied for our RF Multi-Hollow cathode system. The black silicon etched surface shows almost zero reflectance in the visible region as well as in near IR region. The etched silicon surface is covered by columnar microstructures with diameters from 50 to 100 nm and depth of about 500 nm. We have successfully achieved 11.7% efficiency of mono-crystalline silicon solar cell and 10.2% multi-crystalline silicon solar cell.

• 마이크로전자및패키징학회지
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• 제9권4호
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• pp.11-16
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• 2002

본 연구에서는 $SrBi_2Ta_2O_9$ (SBT)박막의 고속식각에 따른 잔류물질 및 식각 손상의 영향을 조사하였다. ICP-RIE (inductively coupled plasma reactive ion etching) 의 ICP power와 CCP(capacitively coupled plasma) power를 변화시키면서 고속식각에 따른 박막의 손상과 열화를 XPS 분석과 Capacitance-Voltage (C-V) 측정을 통하여 알아보았다. ICP와 CCP의 power가 증가함에 따라 식각율이 증가하였고 ICP power가 700 W, CCP power가 200 W 일때 식각율은 900$\AA$/min이었다. 강유전체의 건식식각에 있어서 문제점이 플라즈마에 의한 강유전체 박막의 열화인데 반응가스 $Ar/C1_2/CHF_3$를 20/14/2의 비율로 사용하고 ICP와 CCP power를 각각 700w와 200w로 사용하였을 때 전혀 열화되지 않는 강유전체 박막의 특성을 얻을 수 있었다. 본 연구 결과는 Metal-Ferroelectric-Semiconductor (MFS) 또는 Metal-Ferroelectric-Insulator-Semiconductor (MFIS) 구조를 가지는 단일 트랜지스터형 강유전체 메모리 소자를 만드는데 건식 식각이 응용될 수 있음을 보여준다

• 한국전자현미경학회:학술대회논문집
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• 한국현미경학회 2002년도 제33차 춘계학술대회
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• pp.67-70
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• 2002

• 한국재료학회:학술대회논문집
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• 한국재료학회 2002년도 추계학술발표강연 및 논문개요집
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• pp.48-48
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• 2002