• 한국표면공학회지
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• 제34권5호
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• pp.384-390
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• 2001

The hollow cathode discharge is a kind of plasma formation scheme in which plasma is formed inside a hollow structure, the cathode, with current to a nearby anode of arbitrary shape. In this scheme, electrons reflex radially within the hollow cathode, establishing an efficient ionization mechanism for gas within the cavity. An existence condition for the hollow cathode effect is that the electron mean-free-path for ionization is of the order of the cavity radius. Thus the size of this kind of plasma source must decrease as the gas pressure is increased. In fact, the hollow cathode effect can occur even at atmospheric pressure for cathode diameters of order 10-100 $\mu\textrm{m}$. That is, the "natural" operating pressure regime for a "micro hollow cathode discharge" is atmospheric pressure. This kind of plasma source has been the subject of increasing research activity in recent years. A number of geometric variants have been explored, and operational requirements and typical plasma parameters have been determined. Large arrays of individual tiny sources can be used to form large-area, atmospheric-pressure plasma sources. The simplicity of the method and the capability of operation without the need for the usual vacuum system and its associated limitations, provide a highly attractive option for new approaches to many different kinds of plasma applications, including plasma surface modification technologies. Here we review the background work that has been carried out in this new research field.

• 대한전기학회논문지:전기물성ㆍ응용부문C
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• 제53권2호
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• pp.62-66
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• 2004

This paper investigated the characteristics of a newly developed high density hollow cathode plasma (HCP) system and its application for the etching of silicon wafers. We used SF$_{6}$ and $O_2$ gases in the HCP dry etch process. Silicon etch rate of $0.5\mu\textrm{m}$/min was achieved with $SF_6$$O_2$plasma conditions having a total gas pressure of 50mTorr, and RF power of 100 W. This paper presents surface etching characteristics on a crystalline silicon wafer and large area cast type multicrystlline silicon wafer. The results of this experiment can be used for various display systems such as thin film growth and etching for TFT-LCDs, emitter tip formations for FEDs, and bright plasma discharge for PDP applications.s.

• 전기학회논문지
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• 제57권1호
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• pp.78-81
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• 2008

A hollow cathode which has extremely stable discharge characteristic has been developed. This is composed of the two separated lanthanum hexaboride(LaB6) of a disk type in the tube as the electron emitters. The way of design is of great advantage to extend the surface discharge area of the LaB6, which is also useful for optimal fixing of the LaB6. The hollow cathode is capable of producing 30 kW(100 V, 300 A) of power continuously. Because the generated plasma beam with the high temperature(above $3000^{\circ}C$) from the hollow cathode passes through the center hole of the two intermediate electrodes, it is designed with the high temperature material of the tungsten and the suitable structure of the water cooling. The combinations of the hollow cathode and the two intermediate electrodes are practically useful for the ion plating plasma beam source.

• Journal of Information Display
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• 제2권4호
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• pp.1-7
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• 2001

This paper investigates the characteristics of a newly developed high density hollow cathode plasma(HCP) system and its application for the etching of silicon wafers. We used $SF_6$ and $O_2$ gases in the HCP dry etch process. This paper demonstrates very high plasma density of $2{\times}10^{12}cm^{-3}$ at a discharge current of 20 rna, Silicon etch rate of 1.3 ${\mu}m$/min was achieved with $SF_6/O_2$ plasma conditions of total gas pressure of 50 mTorr, gas flow rate of 40 seem, and RF power of200W. This paper presents surface etching characteristics on a crystalline silicon wafer and large area cast type multicrystlline silicon wafer. We obtained field emitter tips size of less than 0.1 ${\mu}m$ without any photomask step as well as with a conventional photolithography. Our experimental results can be applied to various display systems such as thin film growth and etching for TFT-LCDs, emitter tip formations for FEDs, and bright plasma discharge for PDP applications. In this research, we studied silicon etching properties by using the hollow cathode plasma system.

• 한국전기전자재료학회논문지
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• 제18권4호
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• pp.381-385
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• 2005

The plasma temperature of Ar gas in hollow cathode discharge were measured. This is done by measuring the line profile of the 1s/sub 8/-2p/sub 8/ transition in Ar, using a single-frequency diode laser. Low power diode lasers have been successfully used for investigation of the line profiles of Ar transitions in hollow cathode discharges. It turns out that the plasma temperature of Ar is 640∼783 K in the discharge current range at 7∼10 mA.

• 한국재료학회지
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• 제15권8호
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• pp.521-527
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• 2005

Surface modification of polypropylene hollow fiber membranes was peformed in order to develop blood-compatible biomaterials for use in the blood contacting and oxygenation membranes of a lung-assist device(LAD). Blood compatibility was determined by using anticoagulation blood and evaluating formation of blood clots on their surfaces as well as activation of plasma coagulation cascade, platelet adhesion, and aggregation. It was verified that the number of platelets on the silicone coated fibers was significantly lower than those on polypropylene. It was also found that the polypropylene hollow fiber membranes using plasma treatment exhibited suppression of complement activation in blood compatibility test.

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 2002년도 추계학술대회 논문집 Vol.15
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• pp.488-491
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• 2002

We report the observation of line shapes in the optogalvanic spectrum, which are different from those of absorption, for transitions origination from the $3P_2$ ($1s_5$ in Paschen notation) metastable level of argon. The OG line shapes resemble those of absorption and be used to diagnose the characteristics of the discharge plasma. The measured plasma temperatures of Ar hollow cathode discharge for several metal cathodes are about 620~780K at discharge current of 7~10mA.

• 멤브레인
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• 제15권3호
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• pp.233-240
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• 2005

유용하고 중요한 의료기기인 폐 보조 장치(LAD)의 혈액 접촉 표면과 인공 폐 막에 사용하기 위한 혈액 적합성 생체 재료를 개발하기 위해 폴리프로필렌 중공사 막의 표면 개질을 수행하였다. 재료의 혈액적합성은 항응고 처리된 혈액을 사용하였고 플라스마 응고 형성, 혈소판 접착 및 플라스마 응고 활성화, 그들의 표면 혈전 형성을 평가하여 결정하였다. 실험 결과는 실리콘 코팅 중공사들에 부착한 혈소판 수가 우수한 혈액 적합성을 나타내는 폴리프로필렌에 부착한 혈소판 수보다도 상당히 더 낮았음이 확인되었다. 또한, 상대적으로 플라스마 표면 처리한 폴리프로필렌 중공사 막이 혈액 적합성 평가에서 보체 활성화 억제를 보였음이 확인되었다.

• 열처리공학회지
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• 제25권2호
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• pp.80-84
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• 2012

An apparatus was constructed to nitrify small metallic sintered components by using a hollow-cathode discharge plasma method. A stainless steel basket, which contains a sintered part to be nitrified, is potentially grounded and serves as hollow-cathode electrode. Hollow-cathode plasma was produced by supplying the positive voltage to the anode. In this study sintered carbon iron and stainless steel were used as testing specimens. It was shown that an effective nitrifying took place by controlling the total pressure of nitrogen and hydrogen gas and applied voltage.

• 공업화학
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• 제18권5호
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• pp.438-443
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• 2007

본 연구에서는 티타늄 산화막을 상온에서 HCP (hollow cathode plasma) 반응기에 의하여 증착하였다. HCP 반응기에 대한 시뮬레이션 결과, 전극에서의 열 발생에 관계없이 기판 표면에서의 온도분포는 일정하였다. 그리고 전극과의 거리가 증가하면서 기판 표면에서의 유체는 일정한 것으로 나타났으며, 표면 조도는 거리에 따라 감소하였다. 출력이 증가할수록 산소의 조성은 증가하는 것으로 나타났으며, 출력이 240 watt와 반응 거리가 3 cm에서 Ti와 O의 비율이 1 : 2에 가깝게 결합이 이루어졌다.