• Electrical & Electronic Materials
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• v.9 no.9
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• pp.918-924
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• 1996

A downstream oxygen plasma is generated by capacitively coupled RF power and applied to photoresist stripping. Stripping rate (ashing rate) is measured in terms of RF power, chamber pressure, oxygen flow rate and temperature. Ashing reaction is thermally activated and depends on oxygen radical density. The ashing process is optimized to have the high ashing rate, good uniformity and minimal plasma damage using a statistical method.

• Journal of the Semiconductor & Display Technology
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• v.7 no.2
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• pp.35-38
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• 2008

This study shows the improvement of PR-Ashing rates in semi-conductor process using Atmospheric Plasma. Taguchi method is used to improve Ashing rates of photo-resist that is spread on the surface of a wafer. Improvement of Ashing rates is acquired through the decision of the effective factors and suitable combination of the factors. The results show the contribution rate of each factor and the effectiveness of Plasma for PR-Ashing process in this system.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2010.06a
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• pp.195-195
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• 2010

본 연구에서 제작한 u-bolometer 은 적외선을 흡수하는 멤브레인이 a-Si 위에 Ti 메탈로 이루어져 있다. 이 u-bolometer 는 MEMS 센서로써 3차원 공진 구조를 제작하기 위해서는 희생층을 제거하는 공정이 필수적이며 이 희생 층으로 Polyimide를 사용하고 있는 공정에서 Plasma Ashing 공정은 더욱더 필수적이다. 이 Ashing 공정은 O2 플라즈마를 이용하며 이때 흡수물질인 Ti 레이어가 플라즈마에 의해 면저항과 흡수율의 특성이 어떻게 변화되는지 플라즈마 공정 전후를 분석한 결과 면저항의 변화가 나타났으며 uniformity도 높게 변화하였다. 또한 적외선 흡수율이 약 5% 차이가 나타나는 것을 확인 할 수 있었다.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2008.06a
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• pp.356-357
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• 2008

The effects of $O_2$ plasma ashing process for surface treatment of nano-wire Bio-FET were investigated. In order to evaluate the plasma damage introduced by $O_2$ plasma ashing, a back-gate biasing method was developed and the electrical characteristics as a function of $O_2$ plasma power were measured. Serious degradations of electrical characteristics of nano-wire Bio-FET were observed when the plasma power is higher than 50 W. For curing the plasma damages, a forming gas anneal (2 %, $H_2/N_2$) was carried out at $400^{\circ}C$. As a result, the electrical characteristics of nano-wire Bio-FET were considerably recovered.

• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.31 no.7
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• pp.53-62
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• 2003

• Transactions on Electrical and Electronic Materials
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• v.7 no.4
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• pp.204-209
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• 2006

Photo Resist (PR) ashing process was carried out with the atmospheric pressure- dielectric barrier discharge (ADBD) using $SF_6/N_2/O_2$. Ashing rate (AR) was sensitive to the mixing ratio of the oxygen and nitrogen of the blower type of ADBD asher. The maximum AR of 5000 A/min was achieved at 2% of oxygen in the $N_2$ plasma. With increasing the oxygen concentration to more than 2% in the $N_2$ plasma, the discharge becomes weak due to the high electron affinity of oxygen, resulting in the decrease of AR. When adding 0.5% of SF6 to $O_2/N_2$ mixed plasma, the PR AR increased drastically to 9000 A/min and the ashed surface of PR was smoother compared to the processed surface without $SF_6$. Carbon Fluorinated polymer may passivate the PR surface. It was also observed that the glass surface was not damaged by the fluorine.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.11 no.2
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• pp.95-100
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• 1998

A helical inductively coupled plasma asher, which produces low energy and high density plasma, has been built and investigated for photoresist stripping process. Oxygen ion density in the order of $10^{11}/cm^3$ is measured by Langmuir probe, and higher oxygen radical density is observed by Optical Emission Spectrometer. As RF source power is increased, the plasma density and thus photoresist stripping rate are increased. Independent RF bias power to the wafer stage provides a dc bias to the wafer and an ability to add the ion assisted reaction. At 1 KW of the source power, the coupling mechanism of the RF power to the plasma is changed from the inductive mode to the capacitive one at about 1 Torr. This change causes the plasma density and ashing rate decreases abruptly. The critical pressure of the mode change becomes larger with larger RF power.

• Journal of the Semiconductor & Display Technology
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• v.16 no.2
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• pp.55-60
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• 2017

The supercritical $CO_2$ (sc-$CO_2$) mixture and the sc-$CO_2$-based Photoresist(PR) stripping(SCPS) process were applied to the removal of the post etch/ash PR residue on aluminum patterned wafers and the results were observed by scanning of electron microscope(SEM). In the case of MDII wafers, the carbonized PR was able to be effectively removed without pre-stripping by oxygen plasma ashing by using sc-$CO_2$ mixture containing the optimum formulated additives at the proper pressure and temperature, and the same result was also able to be obtained in the case of HDII wafer. It was found that the efficiency of SCPS of ion implanted wafer improved as the temperature of SCPS was high, so a very large amount of MEA in the sc-$CO_2$ mixture could be reduced if the temperature could be increased at condition that a process permits, and the ion implanted photoresist(IIP) on the wafer was able to be removed completely without pre-treatment of plasma ashing by using the only 1 step SCPS process. By using SCPS process, PR polymers formed on sidewalls of metal conductive layers such as aluminum films, titanium and titanium nitride films by dry etching and ashing processes were removed effectively with the minimization of the corrosion of the metal conductive layers.

• Proceedings of the IEEK Conference
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• 2000.06b
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• pp.290-293
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• 2000

Low frequency(<100Hz) weak magnetic field(<20gauss) is applied axially to an inductively coupled oxygen plasma(ICP), and its plasma characteristics are monitored by OES(Optical Emission Spectroscopy) and Langmuir probe. It is found that periodic magnetic field enhances ashing rate by 25％ and improves its uniformity upto 4.5％ over 8" wafer. From electron energy distribution function, both low and high energy electrons are identified and relative abundancy is found to be controlled by the applied frequency. Moreover, it is observed that ionization and dissociation species are varied with applied frequency. We insert an aluminium baffle in the chamber to get better uniformity and less plasma damage.

• Proceedings of the Korean Vacuum Society Conference
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• 2010.08a
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• pp.291-291
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• 2010

Electron-beam lithography (EBL) process is a versatile tool for a fabrication of nanostructures, nano-gap electrodes or molecular arrays and its application to nano-device. However, it is not appropriate for the fabrication of sub-5 nm features and high-aspect-ratio nanostructures due to the limitation of EBL resolution. In this study, the precision assembly and alignment of DNA molecule was demonstrated using sub-5 nm nanostructures formed by a combination of conventional electron-beam lithography (EBL) and plasma ashing processes. The ma-N2401 (EBL-negative tone resist) nanostructures were patterned by EBL process at a dose of $200\;{\mu}C/cm2$ with 25 kV and then were ashed by a chemical dry etcher at microwave (${\mu}W$) power of 50 W. We confirmed that this method was useful for sub-5 nm patterning of high-aspect-ratio nanostructures. In addition, we also utilized the surface-patterning technique to create the molecular pattern comprised 3-(aminopropyl) triethoxysilane (APS) as adhesion layer and octadecyltrichlorosilane (OTS) as passivation layer. DNA-templated gold nanoparticle chain was attached only on the sub-5 nm APS region defined by the amine groups, but not on surface of the OTS region. We were able to obtain DNA molecules aligned selectively on a SiO2/Si substrate using atomic force microscopy (AFM).