• Proceedings of the Korean Vacuum Society Conference
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• 2010.02a
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• pp.436-436
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• 2010

국내 반도체 시장은 세계 1위의 시장점유율을 가지고 있지만 핵심장비의 경우 국내 장비 기술의 낙후로 인해 대부분을 선진국에 의존하는 실정이다. 따라서 국내 장비 기술의 발전 요구에 따라 연구가 진행되었으며 기존 PE-CVD (Plasma Enhanced Chemical Vapor Deposition) 장비에서의 하전입자에 의한 기판 손상 가능을 제거하고 개개의 반응 원소의 에너지와 플럭스를 조절하여 다양한 공정온도에서 증착을 구현할 수 있는 HNB-CVD(Hyperthermal Neutral Beam Chemical Vapor Deposition) 장비를 개발하였다. 고밀도 플라즈마 생성을 위한 마이크로웨이브 SLAN(Slot Antenna) 소스를 사용하였으며 대면적 공정에 적합하도록 설계하였다. 최적의 설계와 진단을 위한 마이크로웨이브 SLAN 소스내의 E-field 분포 시뮬레이션과 Langmuir Probe 진단이 이루어졌다.

• Asian Journal of Turfgrass Science
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• v.20 no.2
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• pp.223-235
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• 2006

Soil testing laboratories unfamiliar with turfgrasses will often overestimate the plant's need for phosphorus and underestimate the need for potassium. This is partly due to differences in rooting between grasses and many garden plants and crops. The grasses are generally more efficient in extracting phosphorus from the soil, reducing their need for phosphorus fertilizer. The fact that crop yield is often the primary objective in field crop production, and is usually of little interest in turfgrass management, may affect soil test interpretation for potassium. Potassium levels above those required for maximum tissue yield of grasses may improve stress tolerance and turfgrasses will usually benefit from higher applications of this element. There are also diffrrences in soil testing philosophies. Some laboratories use the sufficiency level of available nutrients(SLAN) approach, whereas others prefer the basic cation saturation ratio(BCSR) approach. Some will use a combination of the two methods. The use of the BCSR theory easily lends itself to abuse and questionable fertilizer applications and products are sometimes recommended citing imbalances in cation ratios. The usefulness of the BCSR ratio theory of soil testing varies with soil texture and interpretations on tests performed on sand-based media are particularly a problem. Other soil testing problems occur when sand-based media used on sports fields and golf greens contain free calcium carbonate. The ammonium acetate extractant at pH 7.0 dissolves excessive amounts of calcium that can bias cation exchange capacity measurements and measurements of cation ratios. Adjusting the pH of the extractant to 8.1 can improve the accuracy of the testing procedure for calcareous media.

• Proceedings of the Korean Vacuum Society Conference
• /
• 2010.02a
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• pp.435-435
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• 2010

A inclined slot-excited plasma source is newly designed and constructed for higher flux HNB(Hyperthermal Neutral Beam) generation. The present source is different from the vertical SLAN(SLot ANtenna) sources [1] in two aspects. One is that the slots are inclined, and the other is that the magnetic field is configured to a cusp type. These modifications are intended to make the source plasma operated in sub-milli-torr pressure regime and as thin as possible, both of which is to get higher HNB flux by decreasing the re-ionization rate of the reflected atoms from the neutralizer [2]. The plasma is generated in a quartz tube of internal diameter 170 mm enclosed in a aluminum application chamber of larger diameter 250 mm. The microwave power is fed to the plasma chamber by 8 inclined slots cut into the application chamber wall. The slots are coupled the chamber to a WR280 waveguide wound around it to form a ring resonator. In order to make two slots $\lambda_g/2$ apart in phase, the adjacent slots are rotated in opposite directions. The rotation angle of the slots are set to $60^{\circ}$ from the chamber axis. Between the quartz chamber and the aluminum cylindrical chamber 8 NdFeB magnets are equally spaced and fixed to form the cusp magnetic field confinement and ECR (Electron Cyclotron Resonance) field. In this presentation, the magnetic and electromagnetic simulations, and the measured plasma parameters are given for both the inclined and the vertical slot-excited plasma sources. We also discuss how the sources can be tailored to suit better-performing HNB sources.