• Transactions on Electrical and Electronic Materials
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• 제11권5호
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• pp.202-205
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• 2010

In this study, the etch properties of $Al_2O_3$ thin films deposited by atomic layer deposition were investigated as a function of the $O_2$ content in $BCl_3$/Ar inductively coupled plasma. The experiments were performed by comparing the etch rates and selectivity of $Al_2O_3$ over the hard mask materials as functions of the input plasma parameters, such as the gas mixing ratio, DC-bias voltage, ratio-frequency (RF) power and process pressure. The highest obtained etch rate was 477 nm/min at an RF power of 700 W, $O_2$ to $BCl_3$/Ar gas ratio of 15%, DC-bias voltage of -100 V and process pressure of 15 mTorr. The deposition occurred on the surfaces when the amount of $O_2$ added to the $BCl_3$/Ar gas was too high at a low DC-bias voltage or high process pressure. X-ray photoelectron spectroscopy was used to investigate the chemical reactions on the etched surface.

• 한국전기전자재료학회논문지
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• 제24권6호
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• pp.445-448
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• 2011

In this study, the etching characteristics of $Al_2O_3$ thin films were investigated using an ICP (inductively coupled plasma) of $BCl_3$/Ar gas mixture. The etch rate of $Al_2O_3$ thin films as well as the $SiO_2/Al_2O_3$ etch selectivity were measured as functions of $BCl_3$/Ar mixing ratio (0~100% Ar) at a constant gas pressure (10 mTorr), total gas flow rate (40 sccm), input power (800 W) and bias power (100 W). The behavior of the $Al_2O_3$ etch rate was shown to be quite typical for ion-assisted etch processes with a dominant chemical etch pathway. To analyze the etching mechanism using DLP (double langmuir probe), OES (optical emission spectroscopy) and surface analysis using XPS (x-ray photoelectron spectroscopy) were carried out.

• 대한전기학회논문지:전기물성ㆍ응용부문C
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• 제49권5호
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• pp.265-269
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• 2000

$(Ba, Sr)TiO_3$thin films were etched with a magnetically enhanced inductively coupled plasma (MEICP) at different CF4/Ar gas mixing ratios. Experimental was done by varying the etching parameters such as rf power, dc bias and chamber pressure. The maximum etch rate of the BST films was $1800{AA}/min$ under $CF_4/(CF_4+Ar)$ of 0.1, 600 W/350 V and 5 mTorr. The selectivity of BST to Pt and PR was 0.6, 0.7, respectively. X-ray photoelectron spectroscopy (XPS) results show that surface reaction between Ba, Sr, Ti and C, F radicals occurs during the (Ba, Sr)TiO3 etching. To analyze the composition of surface residue after the etching, films etched with different CF_4/Ar$ gas mixing ratio were investigated using XPS and secondary ion mass spectroscopy (SIMS).

• 대한전기학회:학술대회논문집
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• 대한전기학회 2003년도 추계학술대회 논문집 전기물성,응용부문
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• pp.309-311
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• 2003

The effects of etch parameters on dry etching of BLT thin films were investigated with ICP etch system in $Cl_2$/Ar and $BCl_2/Cl_2$/Ar gas. The etch rate and etch selectivity of BLT films were examined as a function of gas concentration, ICP power, bias power, and pressure. The maximum etch rates of 191.1 nm/min was obtained at the mixed etch condition of $BCl_3(20%)/Cl_2$/Ar, 700 W ICP RF power, 12 mTorr pressure and 400 W substrate RF power. As ICP power and rf power increased, the etch rate of BLT increased. As pressure increased, the etch rate of BLT decreased. The changes of radicals in both $Cl_2$/Ar and $BCl_3/Cl_2$/Ar plasma were measured with using optical emission spectroscopy (OES).

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 2001년도 하계학술대회 논문집
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• pp.866-869
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• 2001

In this study, (Ba,Sr)TiO$_3$(BST) thin films were etched with a magnetically enhanced inductively coupled plasma(MEICP). Etching characteristics of BST thin films including etch rate and selectivity were evaluated as a function of the etching parameters such as gas mixing ratio, rf power, dc bias voltage and chamber pressure. The maximum etch rate of the BST films was 1700 $\AA$/min at Ar(90)/CF$_4$(10), 600 W/350 V and 5 mTorr. The selectivity of BST to PR was 0.6, 0.7, respectively. To analyze the composition of surface residue remaining after the etching, samples etched with different CF$_4$/Ar gas mixing ratio were investigated with X-ray photoelectron spectroscopy (XPS) and secondary ion mass spectrometry (SIMS). From the results of XPS and SIMS, there are chemical reaction between Ba, Sr, Ti and C, F radicals during the etching and remained on the surface.

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 2009년도 춘계학술대회 논문집
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• pp.67-67
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• 2009

본 연구는 강유전체 박막의 buffer 층으로 사용되는 Yttrium oxide($Y_2O_3$) 박막에 대한 $BCl_3$/Ar 혼합가스 식각 특성에 대해 연구하였다. 식각 메카니즘을 해석하기 위해 QMS(Quadrupole Mass Spectrometer), OES(Optical Emission Spectroscopy)를 사용하여 플라즈마 특성을 추출하였다. 공정 조건(source power, bias power, pressure, total gas flow)을 동일하게 유지하고 $BCl_3$/Ar 혼합가스 비율을 변화시키며 실험을 진행 하였다. 혼합가스의 비율이 $BCl_3$(80%)/Ar(20%)일때 가장 높은 식각 속도을 나타냈고, 이후 점차 감소하였다. 이때의 식각 속도는 8.8 nm/min 였다. 이에 $Y_2O_3$는 이온 보조 화학식각 특성을 가짐을 확인하였다.

• 한국진공학회지
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• 제16권2호
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• pp.116-121
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• 2007

Ti-50 at. % Ni 합금 타깃으로 PLD(pulsed laser deposition)방법을 사용하여 TiNi 형상기억합금 박막을 제작하였다. Ar분위기(200 mTorr)와 고진공분위기($5{\times}10^{-6}\;Torr$)에서 제작한 TiNi 박막의 조성 및 결정성의 변화를 조사했으며, 박막의 조성은 에너지 분산 엑스선 분광 분석(EDXS)을 이용하여 조사하였고, 박막의 결정성은 엑스선 회절장치(XRD)를 이용하여 조사하였다. 박막의 조성은 기판과 타깃의 거리에 의존되었지만, 기판의 온도와는 무관함을 알 수 있었으며, Ar 분위기에서 플룸 안쪽에 기판이 위치하였을 때 조성 제어가 용이함을 알 수 있었다. 또한, Ar 가스 분위기에서 증착 된 TiNi 박막은 고진공분위기에서 증착된 박막보다 더 낮은 온도(약 $400^{\circ}C$)에서 in situ로 결정화됨을 알 수 있었다. 이들 결과는, PLD방법으로 TiNi 형상기억합금 박막을 제작할 때 분위기 가스의 압력이 결정화 온도를 낮추어 주는 중요한 역할을 할 수 있음을 시사한다.

• 반도체디스플레이기술학회지
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• 제9권1호
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• pp.35-40
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• 2010

We have investigated the effects of hydrogen injection via in-situ gas addition ($O_2$, $H_2$, or $O_2$ + $H_2$ gas) and plasma post-treatment (Ar or Ar + H plasma) on material properties of ZnO that is considered to be as a channel layer in transparent thin film transistors. The variations in the electrical resistivity, optical transmittance and bandgap energy, and crystal quality of ZnO thin films were characterized in terms of the methods and conditions used in hydrogen injection. The resistivity was significantly decreased by injection of hydrogen; approximately $10^6\;{\Omega}cm$ for as-grown, $1.2\;{\times}\;10^2\;{\Omega}cm$ for in-situ with $O_2/H_2\;=\;2/3$ addition, and $0.1\;{\Omega}cm$ after Ar + H plasma treatment of 90 min. The average transmittance of ZnO films measured at a wavelength of 400-700 nm was gradually increased by increasing the post-treatment time in Ar + H plasma. The optical bandgap energy of ZnO films was almost monotonically increased by decreasing the $O_2/H_2$ ratio in in-situ gas addition or by increasing the post-treatment time in Ar + H plasma, while the post-treatment using Ar plasma hardly affected the bandgap energy. The role of hydrogen in ZnO was discussed by considering the creation and annihilation of oxygen vacancies as well as the formation of shallow donors by hydrogen.

• Transactions on Electrical and Electronic Materials
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• 제10권6호
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• pp.203-207
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• 2009

We have investigated the effect of ambient gases on the structural, electrical, and optical characteristics of ITO thin films intended for use as anode contacts in OLED (organic light emitting diodes) devices. These ITO thin films are deposited by radio frequency (RF) magnetron sputtering under different ambient gases (Ar, Ar+$O_2$, and Ar+$H_2$) at $300{^{\circ}C}$. In order to investigate the influences of the oxygen and hydrogen, the flow rate of oxygen and hydrogen in argon mixing gas has been changed from 0.5 sccm to 5 sccm and from 0.01 sccm to 0.25 sccm, respectively. The intensity of the (400) peak in the ITO thin films increased with increasing $O_2$, flow rate whilst the (400) peak was nearly invisible in an atmosphere of Ar+$H_2$. The electrical resistivity of the ITO thin films increased with increasing $O_2$ flow rate, whereas the electrical resistivity decreased sharply under an Ar+$H_2$ atmosphere and was nearly similar regardless of the $H_2$ flow rate. The change of electrical resistivity with changes in the ambient gas composition was mainly interpreted in terms of the charge carrier mobility rather than the charge carrier concentration. All the films showed an average transmittance of over 80% in the visible range. The OLED device was fabricated with different ITO substrates made with the configuration of ITO/$\alpha$-NPD/DPVB/$Alq_3$/LiF/Al in order to elucidate the performance of the ITO substrate. Current density and luminance of OLED devices with ITO thin films deposited in Ar+$H_2$ ambient gas is the highest among all the ITO thin films.

• 한국표면공학회지
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• 제41권3호
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• pp.83-87
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• 2008

This study described the effects of RF power, DC bias voltage, chamber pressure and gas mixing ratio on the etch rates of TiN thin film and selectivity of TiN thin film to $SiO_2$ with $BCl_3$/Ar gas mixture. When the gas mixing ratio was $BCl_3$(20%)/Ar(80%) with other conditions were fixed, the maximum etch rate of TiN thin film was 170.6 nm/min. When the DC bias voltage increased from -50 V to -200 V, the etch rate of TiN thin film increased from 15 nm/min to 452 nm/min. As the RF power increased and chamber pressure decreased, the etch rate of TiN thin film showed an increasing tendency. When the gas mixing ratio was $BCl_3$(20%)/Ar(80%) under others conditions were fixed, the intensity of optical emission spectra from radical or ion such as Ar(750.4 nm), $Cl^+$(481.9 nm) and $Cl^{2+}$(460.8 nm) was highest. The TiN thin film was effectively removed by the chemically assisted physical etching in $BCl_3$/Ar ICP plasma.