• Journal of the Microelectronics and Packaging Society
• /
• v.8 no.3
• /
• pp.49-53
• /
• 2001

Vortical etching experiments of ($SrBi_2Ta_2O_9$)/Si thin films have been performed by using the inductively coupled plasma reactive ion etching (ICP-ME) apparatus. The purposes of these experiments are to get the effective area of vertical surface. Because this technology is very important to get good qualities of ferroelectric gate structure, capacitor and the minimum parasitic effects related to the excellent performances of the FRAM (Ferroelectric Random Access Memory) device. The reacting gases were Ar and $Cl_2$gases, and various $Ar/C1_2$flow ratios were used. The etching experiments were carried out at various RF powers such as 700, 700, 500W and at various DC powers such as 200, 150, 100, 50W, respectively. The maximum etch rate of $SrBi_2Ta_2O_9$/Si thin films was 1050 A/min at the $Ar/C1_2$ gas ratio of 20/16, RF power of 700 W and DC power of 200 W. From the SEM (scanning electron microscopy) image of the SBT thin films, the wall angle was as good as about $82^{\circ}$.

• Journal of the Korean Vacuum Society
• /
• v.19 no.1
• /
• pp.45-51
• /
• 2010

We measured the temperature of target surface inducing by various physical phenomenon on magnetron sputtering target and confirmed the possibilities if the temperature distribution could affect plasma and deposited thin film. The target of magnetron sputtering has two types: round type and rectangular type. In a rectangular target, the concentrated discharge area by corner effect by magnetic field and non-uniform erosion of target are generated. And we found the generation of non-uniform temperature distribution on the target surface from this. This area was $10{\sim}20^{\circ}C$ higher than non-sputtering area. And if particles are generated during sputtering process, they were $20^{\circ}C$ higher than the area where is higher than non-sputtering area. These effects result in non-uniformity of thin films, crack of ceramic target, and shortening target life by non-uniform erosion.

• Applied Chemistry for Engineering
• /
• v.19 no.3
• /
• pp.270-276
• /
• 2008

$N_2$ doped $TiO_2$ nano-sized powder was prepared using a DC arc plasma jet and investigated with XRD, BET, SEM, TEM, and photo-catalytic decomposition. Recently the research interest about the nano-sized $TiO_2$ powder has been increased to improve its photo-catalytic activity for the removal of environmental pollutants. Nitrogen gas, reacting gas, and titanium tetrachloride ($TiCl_4$) were used as the raw materials and injected into the plasma reactor to synthesize the $N_2$ doped $TiO_2$ power. The particle size and XRD peaks of the synthesized powder were analyzed as a function of the flow rate of the nitrogen gas. Also, the characteristics of the photo-catalytic decomposition using the prepared powder were studied. For comparing the photo-catalytic decomposition performance of $TiO_2$ powder with that of $TiO_2$ coating, $TiO_2$ thin films were prepared by the spin coating and the pulsed laser deposition. For the results of the acetaldehyde decomposition, the photo-catalytic activity of $TiO_{2-x}N_x$ powder was higher than that of the pure $TiO_2$ powder in the visible light region. For the methylene blue decomposition, the decomposition efficiency of $TiO_2$ powder was also higher than that of $TiO_2$ film.

• The Transactions of the Korean Institute of Electrical Engineers C
• /
• v.49 no.5
• /
• pp.265-269
• /
• 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).

• Proceedings of the Korean Institute of IIIuminating and Electrical Installation Engineers Conference
• /
• 2001.11a
• /
• pp.39-46
• /
• 2001

The plasma display panel with the electrode structure of new discharge AND gate was developed and the driving system for experiment was developed. And discharge AND gate operation was verified. Discharge AND gate operated by the operation speed of 8$mutextrm{s}$ and the operation margin of 20V. It was known to be able to control the discharge of the adjoining scan electrode accurately. Because this method uses the DC discharge, the control of the discharge can be facilitated compared with conventional discharge AND gate. Moreover, because the imput discharge and the output discharge of AND gate are separate, the display discharge can be prevented from passing AND gate. Therefore, it is possible to apply to the large screen plasma display. And the decrease of contrast ratio does not occur because the scanning electrical discharge does not influence the picture quality.

• The Proceedings of the Korean Institute of Illuminating and Electrical Installation Engineers
• /
• v.10 no.6
• /
• pp.73-80
• /
• 1996

본 논문은 펄스 형태의 출력전류를 얻기 위한 직류 직원 장치의 성능분석에 관한 것이다. 직류 전원장치의 입력은 3상 3,300[V]이고 펄스 출력용량은 4.2MW( 600VDC, 7kADC)이며 용도는 플라즈마의 밀폐 및 구속을 위한 전자적 구동용이다. 펄스폭인 10초인 펄스 파형이 150초 주기로 출력되면서 동작함에 따라 전원장치를 구성하는 변압기와 위상제어 정류기의 용량선정시 전원장치의 성능과 설비비를 고려하여 최적화할 필요가 있다. 본 논문에서는 변압기의 용량선정시 역률과 전압강하를 고려하여 가능한 한 용량을 최소화하였으며 선정된 변압기에 대하여 변압기의 %Z에 따른 직류 출력전압 강하, 역류, 전고조파 왜율 등의 특성을 시뮬레이션을 통하여 분석하였으며 제작된 전원장치의 실험을 통하여 분석하였으며 제작된 전원장치의 실험을 통하여 분석의 타당성을 검증하였다. 특히, 전원장치의 과부하 동작시 변압기의 %Z가 출력성능에 미치는 영향에 대하여 중점적으로 시뮬레이션 하였으며 실험적으로 확인하였다.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
• /
• 1998.11a
• /
• pp.323-326
• /
• 1998

The current-voltage characteristic have been measured in a gas stabilized DC arc generated in a non-transferred arc plasma torch operating on a mixture of argon and nitrogen. Relation between voltage and current to these arcs has been examined by plasma power and current under different flow rates and gas mixture ratios. Firstly, the voltage and current of arc plasma used argon was measured and secondly, in argon-nitrogen mixed gas regime, the flow rate of nitrogen was increased slowly. When the flow rate of nitrogen was increased, electrode drop of potential was increased.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
• /
• 2001.07a
• /
• pp.866-869
• /
• 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.

• Proceedings of the KIEE Conference
• /
• 1989.07a
• /
• pp.451-454
• /
• 1989

A DC thermal plasma generation system for both LPPS and APPS was designed and its characteristics was analysed. Discharge experiments for 60 conical and cylindrical type anode nozzle were conducted and the results were compaerd each other. The flow dependence and the electrode gap dependence were precisely explained and especially voltage jump phenomena under the existance of the parallel magnetic field was studid.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
• /
• 2010.06a
• /
• pp.385-385
• /
• 2010

In this work, we have investigated the etching characteristics of $TiO_2$ and selectivity of $TiO_2$ over $SiO_2$ thin films as resistance in ReRAM using the inductively coupled plasma. The etch rate and selectivity were measured by varying the $BCl_3$ addition into Ar plasma. The maximum etchrate was obtained at 110.1nm/min at $BCl_3$/Ar=5sccm/10sccm, 500W for RFpower, -100v for DC-bias voltage, and 2Pa for the process pressure. The etched $TiO_2$ surface was investigated with X-ray photo electron spectroscopy. We explained the etching mechanism in two etch mechanisms, physiclas puttering and chemical reaction.