• Journal of the Korean Vacuum Society
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• v.9 no.4
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• pp.428-435
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• 2000

Negative ion generation in an inductively coupled oxygen plasma was investigated by using a Langmuir probe. It was observed that the probe current ratio of the positive ion saturation current and the negative current which is consisted of the electron current and the negative ion current, and also the potential difference between the floating potential and plasma potential vary with the RF input power and more sensitively with the operating pressure, respectively. Results show that the operating condition to achieve the maximum probe current ratio and the minimum potential difference shift from the low pressure region to the high pressure regions with increasing the input power. It implies that the generation of the negative oxygen ions increases and the recombination of the positive and negative ions are enhanced in the plasma.

• Journal of Astronomy and Space Sciences
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• v.15 no.2
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• pp.401-415
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• 1998

This paper reports the results obtained from the Langmuir probe (LP) and Electron Temperature Probe (ETP) experiments on the sounding rocket KSR-II (Korean Scientific Rocket - II) which was launched on Jun 11, 1998 at 10:00 KST from Tae-An peninsula (37$^{\circ}$ N, 126$^{\circ}$ E). The instruments successfully measured the electron density, electron temperature, and the floating potential at altitudes of 73km to 130km. While the electron temperature measurement is not easy in this region, since the temperature is very low and the contamination effect of the probe may give rise to a problem, we were able to obtain a reasonable electron temperature profile by employing two independent methods, the pulse modulated Langmuir Probe and Electron Temperature Probe. The preliminary results show that electron density increases sharply at about 90km, and forms a peak at 102km. The density profile is roughly consistent with IRI (International Reference Ionosphere)95-model or PIM (Parameterized Ionospheric Model) results except that the peak density appears at 110km in the model and model electron density is slightly lower than the observed one. Electron temperature obtained from ETP fluctuates between 200$^{\circ}$K and 700$^{\circ}$K, an effect presumably coming from the wakes developed by LP, and it tends to increase with the altitude, which is consistent with the LP results.

• Journal of the Korean institute of surface engineering
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• v.44 no.1
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• pp.26-31
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• 2011

Numerical modeling is used to investigate the perturbation of a single Langmuir probe (0.2 mm diameter shielded with 6 mm insulator) inserted along the center axis of a cylindrical inductively coupled plasma chamber filled with Ar at 10 mTorr and driven by 13 MHz. The probe was driven by a sine wave. When the probe tip is close to a substrate by 24.5 mm, the probe characteristics was unperturbed. At 10 mm above the substrate, the time averaged electric potential distribution around the tip was severly distorted making a normal probe analysis impossible.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2006.05a
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• pp.91-95
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• 2006

In whole world consciousness of environment maintenance have increased very quickly for the end of the 20th century. To use and disuse toxic substances have been controled at the field of industry. Also the field of lighting source belong to environmental control. And in the future the control will be strong. In radiational mechanism of fluorescence lamp mechanism is the worst environmental problem. In radiational mechanism of fluorescence lamp mercury is the worst environmental problem root. In the mercury free lighting source system the Xe gas lamp is one type. And the Ne:Xe mixing gas lamp improvements firing voltage of Xe gas lamp. Purpose and subject of this study are understand, efficiency, ideal of Ne:Xe plasma which mercury free lamp. Before ICP was designed, basic parameters of plasma, which are electron temperature and electron density, were measured and calculated by Langmuir probe data. Property of electron temperature and electron density were confirmed by changing ratio of Ne:Xe.

• Publications of The Korean Astronomical Society
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• v.15 no.spc2
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• pp.37-44
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• 2000

Two different types of plasma probes have been developed and are currently in operation on board the KOMPSAT-l. One is the cylindrical Langmuir Probe (LP) that measures the electron density and temperature from its current-voltage characteristics in thermal plasmas, and the other is the Electron Temperature Sensor (ETS) which directly gives the information of the ambient electron temperatures. These plasma probes provide the electron properties of the local nighttime ionosphere at the KOMPSAT-l altitudes. In this paper we briefly describe the probes and the initial results obtained from these probes since the beginning of their normal operation in April, 2000.

• Proceedings of the KIEE Conference
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• 2011.07a
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• pp.1528-1529
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• 2011

플라즈마 변수를 측정하기 위한 가장 일반적인 방법은 정전탐침(Langmuir Probe)을 이용하는 것이다. 정전탐침은 RF 플라즈마 내에 삽입될 경우 탐침의 전위가 플라즈마 전위에 의해 진동하여 탐침전류의 왜곡이 발생하여 정확한 플라즈마 변수 측정이 어렵다. 탐침 전위의 변동을 최소화하기 위해 임피던스가 큰 인덕터를 탐침 회로 내에 삽입한다. 본 연구에서는 자기 공명 주파수가 13.56MHz 근방의 인덕터 3종류를 선정하여 간단한 RF 보상 정전탐침을 제작하여 유도결합형 플라즈마의 특성을 측정하였다. RF 보상 정전탐침에 의해 구해진 플라즈마의 전자 온도 및 플라즈마 전위는 감소하며, 플라즈마의 전자 밀도는 증가함을 알 수 있었다.

• Proceedings of the Korean Institute of Surface Engineering Conference
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• 2009.05a
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• pp.247-247
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• 2009

3차원 반도체 패키징에서 관통전극 Through Silicon Via (TSV)를 형성하기 위하여 이온과 래디컬의 활성도 조절이 가능한 pulsating inductively coupled plasma (ICP) 식각을 수행하였다. 본 식각공정에서는 펄스주파수 ($50{\sim}500Hz$)와 듀티 싸이클 ($20{\sim}99%$)을 조절하여, 플라즈마 내 이온과 래디컬들의 활성도 변화를 발생시켰다. 플라즈마 공정변수에 따라 식각형태가 달라짐을 S.E.M을 이용하여 확인했으며, 이온(SFx+, O+)과 래디컬 ($SF^*$, $F^*$, $O^*$)의 농도 및 활성도 변화를 측정하기 위하여 광학적 기술인 optical emissin spectroscopy와 전기적 특성 측정 기술인 Langmuir probe 시스템을 직접 제작 설치하여 펄스플라즈마를 진단하였다.

• Proceedings of the Korean Vacuum Society Conference
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• 2011.02a
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• pp.216-216
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• 2011

There have been various direct or indirect methods to measure the characteristics of plasma. Comparing to direct method like Langmuir probe method, indirect measurements which give information as some external parameters like current, voltage, or phase are easier to obtain. In this research, an indirect method to measure averaged plasma density in a transformer coupled plasma(TCP) has been proposed and evaluated. With a simple analytic model connecting electrical characteristics to plasma impedance, direct measurement via double Langmuir probe has been performed. This result may play a meaningful role to diagnose TCP or similar plasma sources

• Proceedings of the Korean Vacuum Society Conference
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• 2011.02a
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• pp.213-213
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• 2011

DC arc plasmatron is powerful plasma source to apply etching and texturing processing. Even though DC arc plasmatron has many advantages, it is difficult to apply an industry due to the small applied area. To increase an effective processing area, we suggest a DC-RF hybrid plasma system. The DC-RF hybrid plasma system was designed and made. This system consists of a DC arc plasmatron, RF parts, reaction chamber, power feeder, gas control system and vacuum system. To investigate a DC-RF hybrid plasma, we used a Langmuir probe, OES (Optical emission spectroscopy), infrared (IR) light camera. For RF matching, PSIM software was used to simulate a current of an impedance coil. The results of Langmuir probe measurements, we obtain a homogeneous plasma density and electron temperature those are about $1{\times}1010$ #/cm3 and 1~4 eV. The DC-RF hybrid plasma source is applied for plasma etching experimental, and we obtain an etching rate of 10 ${\mu}m$/min. through a 90 mm of reaction chamber diameter.

• Proceedings of the KIEE Conference
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• 1998.07e
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• pp.1797-1799
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• 1998

Plasma source ion implantation(PSII) is a non-line-of-sight technique for surface modification of materials which is effective for non-planar targets. A apparatus of 30kV PSII is established and plasma characteristics are diagnosed by using a Langmuir probe. A spherical target is immersed in argon plasma and biased negatively by a series of high voltage pulses. Sheath evolution is measured by using a Langmuir probe and compared with the result of computer simulations.