• Korean Journal of Materials Research
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• v.10 no.12
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• pp.819-824
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• 2000

In this research, the etching characteristics of Ta thin film with chlorine plsama have been studied by Electron Cyclotron Resonance (ECR) plasma etching system. The effects of microwave power, RF bias power, working pressure and gas chemistry on the etching profiles have been investigated. The microloading effect, which was observed at fine pattern formation, was effectively suppressed by double step etching, and anisotropic $0.2{\mu\textrm{m}}$ L&S patterns were successfully generated.

• Progress in Superconductivity and Cryogenics
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• v.17 no.2
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• pp.36-40
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• 2015

Electron cyclotron resonance (ECR) ion source is an essential component of heavy-ion accelerator. For a given design, the intensities of the highly charged ion beams extracted from the source can be increased by enlarging the physical volume of ECR zone [1]. Several models for ECR ion source were and will be constructed depending on their operating conditions [2-4]. In this paper three simulation models with 3, 4 and 6 solenoid system were built, but it's not considered anything else except the number of coils. Two groups of optimization analysis are presented, and the evolution strategy (ES) is adopted as an optimization tool which is a technique based on the ideas of mutation, adaptation and annealing [5]. In this research, the volume of ECR zone was calculated approximately, and optimized designs for ECR solenoid magnet system were presented. Firstly it is better to make the volume of ECR zone large to increase the intensity of ion beam under the specific confinement field conditions. At the same time the total volume of superconducting solenoids must be decreased to save material. By considering the volume of ECR zone and the total length of solenoids in each model with different number of coils, the 6 solenoid system represented the highest coil performance. By the way, a certain case, ECR zone volume itself can be essential than the cost. So the maximum ECR zone volume for each solenoid magnet system was calculated respectively with the same size of the plasma chamber and the total magnet space. By comparing the volume of ECR zone, the 6 solenoid system can be also made with the maximum ECR zone volume.

• Proceedings of the Korean Vacuum Society Conference
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• 1999.07a
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• pp.47-47
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• 1999

2.45 GHz 마이크로웨이브를 이용하는 electron cyclotron resonance plasma enhanced chemical vapor deposition(ECR-PECVD)방법으로 다이아몬드성 탄소박막(diamond-like carbon, DLC)을 증착하였다. DLC 박막의 산업 응용을 위해서는 높은 경도와 밀착력이 필요하다. 그래서 본 실험에서는 DLC 박막의 산업 응용을 위하여 ECR-PECVD 방법으로 증착된 DLC 박막의 분석결과로부터 DLC 박막의 물성과 증착조건의 관계를 조사하였다. 기판으로는 실리콘 웨이퍼와 실험용 SUS 판을 사용하였다. 아르곤 가스를 주입하여 ECR 마이크로 웨이브 플라즈마와 negative DC bias로 기판을 플라즈마 세척한 후, 수소와 메탄가스를 반응기체로 하여 DLC 박막을 증착하였다. 박막 증착시에 13.56MHz RF 전원 공급장치로 기판에 전원을 공급하였다. DLC 박막 증착의 변수는 반응기체의 호합율, 마이크로웨이브 파워, 프로세스 압력 및 RF 전원공급장치에서 유도되는 negative self DC bias 등이다. 이때 사용된 반응기체의 혼합율(메탄/수소)은 10~50%이고, 수소 가스 흐름율은 100sccm, 메탄은 10~50sccm이다. 마이크로웨이브의 크기는 360~900W, negative self DC bias는 -500~-10 V였다. 그리고 본 실험에서는 높은 증착율을 고려하여 프로세스 압력을 10~30mTorr까지 조절하였다. ER-PECVD 방법으로 증착된 DLC 박막은 SEM으로 단면, $\alpha$-Step으로 두께, Raman 분광계로 탄소 결합구조, FTIR 분광계로 탄소와 수소 결합구조, Micro-Hardness로 경도 그리고 Scratch Tester로 밀착력 등을 분석하였다.

• Proceedings of the Korean Vacuum Society Conference
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• 2015.08a
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• pp.70.1-70.1
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• 2015

The facility for RAON superconducting heavy-ion accelerator at a beam power of up to 400 kW will be produced rare isotopes with two electron cyclotron resonance (ECR) ion sources. Highly charged ions generated by the ECR ion source will be injected to a superconducting LINAC to accelerate them up to 200 MeV/u. During the acceleration of the heavy ions, a good vacuum system is required to avoid beam loss due to interaction with residual gases. Therefore ultra-high vacuum (UHV) is required to (i) limit beam losses, (ii) keep the radiation induced within safe levels, and (iii) prevent contamination of superconducting cavities by residual gas. In this work, a RAON vacuum design for all the accelerator system will be presented along with Monte Carlo simulation of vacuum levels in order to validate the vacuum hardware configuration, which is needed to meet the baseline requirements.

• Journal of the Korean Institute of Telematics and Electronics A
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• v.29A no.10
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• pp.35-41
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• 1992

Ultra-thin silicon nitride films were fabricated with ECR(Electron cyclotron Resonance) nitrogen plasma at room temperature. Film thickness was about 50$\AA$ after nitridation for 1min at microwave power of 1000W, RF power of 500W, and NS12T pressure of ${\times}10^{-3}$ torr. 50$\AA$ fo nitride film was grown within 1 min and no appreciable growth occured thereafter. Dielectric breakdown strength and leakage current density in Al/SiN/Si structure were measured to be about 7-11 MV/cm and ${\times}10^{-10}~5{\times}10^{-10}A/cm^{2}$, respectively. Observed linear relationship in 1n(J/E)-vs-E$^{1/2}$ and no polarity-dependence of the leakage current indicated that the Poole-Frenkel emission is mainly responsible for the conduction in this nitrided silicon films.

• Journal of the Korean institute of surface engineering
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• v.24 no.4
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• pp.215-221
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• 1991

Microstructure evolution during low temperature vapor deposition exhibits wel-developed columnar structure mainly owing to geometrical shadowing effect of surface roughness. It is concluded that this structure is concided with many theoretical models suggested so far. In case of aluminum nitride film deposition consisted of etching and nitriding step employing ECR plasma, the rougher the surface before etching, the finer and more cone-and-whisker structure can be developed. In turn, this fine structure affects the formation and growth of columnar as well as offers many sites available for mechanical lock-up. Conclusively, the formation of well-defined columnar structures depends on the initial surface roughness.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2005.07a
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• pp.153-156
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• 2005

원자층 증착 (atomic layer deposit : ALD) 방식으로 증착한 $Al_2O_3$의 건식식각 특성을 연구하였다. 전자 싸이클로트론 공진 (electron cyclotron resonance : ECR) 방식의 건식식각장치에서 source power, bias power, 압력 그리고 $Cl_2$ 가스를 변수로 하여 $Al_2O_3$의 식각속도와 Poly-Si 의 $Al_2O_3$에 대한 선택비를 측정하였다. bias power가 감소할수록 그리고 압력이 증가할수록 $Al_2O_3$의 식각속도는 감소하였고 Poly-Si 의 $Al_2O_3$에 대한 선택비는 증가하였다. 이 특성을 이용하여 TiN/$Al_2O_3$/Poly-Si 구조의 캐패시터와 Periphery 회로영역의 레지스터를 $Al_2O_3$를 식각 정지막으로 이용하여 구현하였다.

• Korean Journal of Materials Research
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• v.14 no.3
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• pp.203-210
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• 2004

Effects of various pretreatments on the adhesion of copper-coated polymer films were investigated. Copper-coated polymer films were prepared by an electron cyclotron resonance-metal organic chemical vapor deposition (ECR-MOCVD) coupled with a DC bias system at room temperature. PET(polyethylene terephthalate) film was employed as a substrate material and it was pretreated by industrially feasible methods such as chromic acid, sand-blasting, oxygen plasma and ion-implantation treatment. Surface characterization of the copper-coated polymer film was carried out by AFM(Atomic Force Microscopy) and FESEM(Field Emission Scanning Electron Microscopy). Surface energy was calculated by based on the value of the contact angle measured. The adhesion of copper/PET films was determined by a pull-off test according to ASTM D-5179. It was found that suitable pretreatment of the PET substrate was required for obtaining good adhesion property between copper films and the substrate. In this study the highest adhesion was observed in sand-blasting, and then followed by those of acid and oxygen plasma treatment. However, the effect of surface energy was insignificant in our experimental range. This is probably due to compensating the difference in surface energy from various pretreatments by exposing substrate to ECR plasma for 5 min or longer at the early stage of the copper deposition. Therefore, it can be concluded that surface roughness of the polymer substrate plays an important role to determine the adhesion of copper-coated polymer for the deposition of copper by ECR-MOCVD.

• Journal of the Korean Vacuum Society
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• v.10 no.1
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• pp.119-126
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• 2001

Hydrogenated amorphous carbon (a-C:H) films were deposited by ECR-PECVD (electron cyclotron resonance-plasma enhanced chemical vapor deposition) method with deposition conditions such as ECR plasma source power, gas composition of methane and hydrogen, deposition time and substrate bias voltage. The hydrogen content in the films has been measured by ERDA (elastic recoil detection analysis) using 2.5 MeV $He^{++}$ ion beam. From the results of AES (Auger electron spectroscopy), RBS (Rutherford backscattering spectrometry) and ERDA, the composition elements of deposited film were confirmed the carbon atom and the hydrogen atom. It was observed by FTIR (Fourier transform infrared) that the hydrogen contents in the film varied according to the deposition conditions. In deposition condition of substrate bias voltage, the hydrogen contents were decreased remarkably because the amount of dehydrogenation in films was increased as the substrate bias voltage increased. In the rest deposition conditions, the hydrogen contents in the film were measured in the range 45~55%.

• Journal of the Korean Magnetics Society
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• v.25 no.4
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• pp.117-122
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• 2015

The holes with a diameter of $35{\mu}m$ inside the GMR-SV (giant magnetoresistance-spin valve) film were patterned by using the photolithography process and ECR (electron cyclotron resonance) Ar-ion milling. From the magnetoresistance curves of the GMR-SV film with holes measuring by 4-electrode method, the MR (magnetoresistance ratio) and MS (magnetic sensitivity) are almost same as the values of initial states. On other side hand, the $H_{ex}$ (exchange bias coupling field) and $H_c$ (coercivity) dominantly increased from 120 Oe and 10 Oe to 190 Oe and 41 Oe as increment of the number of holes inside GMR-SV film respectively. These results were shown to be attributed to major effect of EMD (easy magnetic domian) having a region positioned between two holes perpendicular to the sensing current. On the basis of this study, the fabrication of GMR-SV applying to the hole formation improved the magnetoresistance properties having the thermal stability and durability of bio-device.