• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2007.06a
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• pp.162-163
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• 2007

The dry etching of Si was investigated using direct dc biasing to the Si substrate. The TCP type etching system with a feed-through for applying a dc bias was used in the etching. The applied dc bias and ICP power was varied to examine the effect on the etching at the fixed chamber pressure and $SF_6$ flow rate of 10 mTorr and 10 sccm during. When the plasma was generated at ICP power of 100 W, the etch rate of Si was increased with the bias for the biased samples. However, the etching of Si for the non-biased sample was enhanced for the increased ICP power.

• Journal of the Institute of Electronics Engineers of Korea TC
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• v.47 no.1
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• pp.53-57
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• 2010

This study proposes the algorithm which drives the powerless without battery. The exiting wire or RF type dosimeter, which is the computation of the real time with battery on the dose radiation exposure, In the Wired dosimeter, it is trouble to need the maintenance and management by periods. Besides, the case of the RF typed dosimeter with battery, it is requested to size bigger and to replace battery frequently and so on. Especially RF typed dosimeter has trouble to need for the embody with large power consumption on the contactless typed dosimeter. As the method for the low power, the study designed to be down the operating clock of the MPC, to improve the efficiency of the rectifier, to eliminate the external memory and the DC-DC converter for the simplification of the circuit We convince our research contributes not only to understand the simplified circuit and miniaturization, but also to help the design and application technology of the powerless dosimeter.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2006.05a
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• pp.902-905
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• 2006

This paper presents a new RF testing scheme based on a design-for-testability (DFT) method for measuring functional specifications of RF integrated circuits (IC). The proposed method provides input impedance. gain, noise figure. input voltage standing wave ratio (VSWR) and output signal-to-noise ratio (SNR) of a low noise amplifier (LNA). The RF test scheme is based on theoretical expressions that produce the actual RF device specifications by output DC voltages from the DR chip.

• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.23 no.1
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• pp.182-187
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• 2009

In this paper, the power management module of wireless sensor node is designed and fabricated utilizing RF energy from reader antenna of commercial RFID system, which is mainly categorized in the energy harvesting. For this, the rectenna and the high efficient boost converter is designed to get the DC power from RF power for the charging the battery. When the RF power from RFID reader antenna is 1.2[W], the DC power of 3.1[mW] at the distance of 1[m] and 1[mW] at 5.5[m] are obtained. Considering the connection to the battery, the boost converter for enhancing the conversion efficiency is designed. The conversion efficiency at the distance of 4[m] is 79.3[%] and the harvested power is 1.36[mW] which is actually used for the charging the battery. This value is available in the wireless sensor networking.

• Journal of the Microelectronics and Packaging Society
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• v.12 no.3 s.36
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• pp.207-212
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• 2005

Al, Ti, Ta, and Cr thin films were deposited on a polyimide substrate using DC magnetron sputter to study the adhesion characteristics of metal films on polyimide substrates, while RF bias of 0 - 400 W was applied to the substrate during DC sputtering. The adhesion strength was evaluated using a 90-degree peel test. The peel tests showed that the adhesion strength was enhanced by applying the RF bias to the substrate in all specimens. Scanning electron microscopy and Auger depth profile of the fractured surfaces indicate that the polyimide underwent cohesive failure during peeling and heavy deformation was also observed in the metal films peeled from the polyimide substrate when the RF bias applied during the deposition. Cross-sectional transmission electron microscopy revealed that the metal/polyimide interface was not clear and complicated. This complicated interface, likely formed due to the RF bias applied to the substrate, was attributed to the adhesion enhancement observed during the bias sputtering.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.15 no.6
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• pp.573-578
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• 2004

EED consists of bridgewire, explosive charge, lead pins and metal case. If a firing signal is injected to EED， the explosive charge in EED is initiated by heating of bridgewire. Electromagnetic waves radiated from high power transmitters or radars can also cause unexpected firing of EED. Therefore, EMC design and test requirements for EED in military specifications are established and applied. This report describes the characteristics of RF sensitivity fur a firing fuse which is used fur EMC test instead of a real EED installed in aircraft. RF firing level of the fuse was predicted using transmission line(TL) theory. n sensitivity and RF sensitivity specified in military specifications were measured.

• Journal of the Institute of Electronics Engineers of Korea SD
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• v.38 no.1
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• pp.13-22
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• 2001

This paper presents three dimensional structure of RF packages and the improvement effect of its electrical characteristics when implementing RF transceivers. We divided RF modules into several subunits following each subunit function based on the partitioning algorithm which suggests a method of three dimension stacking interconnection, PAA(pad area array) interconnection and stacking of three dimensional RF package structures. 224MHz ITS(Intelligent Transportation System) RF module subdivided into subunits of functional blocks of a receiver(RX), a transmitter(TX), a phase locked loop(PLL) and power(PWR) unit, simultaneously meeting the requirements of impedance characteristic and system stability. Each sub­functional unit has its own frequency region of 224MHz, 21.4MHz, and 450KHz~DC. The signal gain of receiver and transmitter unit showed 18.9㏈, 23.9㏈. PLL and PWR modules also provided stable phase locking, constant voltages which agree with design specifications and maximize their characteristics. The RF module of three dimension stacking structure showed $48cm^3$, 76.9％ reduction in volume and 4.8cm, 28.4％ in net length, 41.8$^{\circ}C$, 37% in maximum operating temperature, respectively. We have found that three dimensional PAA package structure is able to produce high speed, high density, low power characteristics and to improve its functional characteristics by subdividing RF modules according to the subunit function and the operating frequency, and the features of physical volume, electrical characteristics, and thermal conditions compared to two dimensional RF circuit modules.

• Transactions on Electrical and Electronic Materials
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• v.14 no.3
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• pp.116-120
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• 2013

This paper proposes a novel RF MEMS dc-contact switch with stiff membrane on a quartz substrate. The uniqueness of this work lies in the utilization of a seesaw mechanism to restore the movable part to its rest position. The switching action is done by using separate pull-down and pull-up electrodes, and hence operation of the switch does not rely on the elastic recovery force of the membrane. One of the main problems faced by electrostatically actuated MEMS switches is the high operational voltages, which results from bending of the membrane, due to internal stress gradient. This is resolved by using a stiff and thick membrane. This membrane consists of flexible meanders, for easy movement between the two states. The device operates with an actuation voltage of 6.43 V, an insertion loss of -0.047 dB and isolation of -51.82 dB at 2 GHz.

• Proceedings of the Korean Vacuum Society Conference
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• 2010.08a
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• pp.8-8
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• 2010

본 발표에서는 OLED, LCD, E-ink 등에 적용되는 고품질 전도성 투명 산화막의 구조, 전기적 성질, 광학적 성질, 표면 거칠기 등에 미치는 공정 변수의 영향을 유연 기판 적용 사례를 들어서 설명한다. 특히 RF superimposed dc sputtering 방법으로 성장시킨 TCO의 특성이 현재 알려진 어떤 방법보다도 우수한 특성들과 유연 기판에 필수적인 내절성을 갖는 결과를 보여주고 있음에 주목하고 그 원리 및 대형화 가능성에 대해서 언급한다. 증착된 박막의 투습성 평가에서 측정 장비의 한계치 이하를 달성하였고 플라즈마를 이용한 중간 처리 과정의 효과로 PC, PET 등의 필름 기판에서도 우수한 성질을 갖는 박막의 성공적인 증착이 이루어 졌음을 설명한다. 여기에는 적절한 산소 분압의 유지가 관건이며 이미 재료연구소에서는 대형 타겟 시스템에 대해서 안정된 공정을 운영하고 있다. RF superimposed dc power의 특징은 타겟에서 반사되는 고속 중성 입자의 유속을 적절하게 제어할 수 있다는 점으로 판단되며 이는 주로 산소 원자와 산소 음이온의 에너지가 높다는 점에 주목할 필요가 있다. Carcia등의 보고에 따르면 산소 음이온의 경우에는 110 eV가 넘는 운동 에너지를 가지고 성장 중인 박막에 입사하여 결함을 생성한다고 한다. 이들 고속 입자들의 에너지를 낮추고 그 수를 감소시킬 수 있는 방법 중의 하나가 RF superimposed dc라고 판단된다.

• Proceedings of the Korean Institute of Surface Engineering Conference
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• 2013.05a
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• pp.202-203
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• 2013

CIGS 단일 타켓을 DC 및 RF 마그네트론 스퍼터링을 이용하여 파워별로 Mo/SLG위에 증착하여 미세구조 및 화학조성 평가를 실시하였다. 파워가 증가함에 따라 이온의 운동에너지 증가에 따라서 결정성이 향상되었음을 확인할 수 있었다. DC 마그네트론 스퍼터링의 경우 40W에서 가장 결정성이 좋았으며, RF 마그네트론 스퍼터링은 80W에서 높은 결정성을 확인할 수 있었다. 이는 DC power 40W와 RF power 80W에서 박막의 조성이 화학양론을 만족하고 grain의 성장이 잘되었기 때문에 높은 결정성을 나타났다고 생각된다. 그리고 최적의 80W에서 기판온도를 100~400도까지 변화하여 증착해본 결과 300도에서 증착 시 가장 높은 결정성이 나타나는 것을 확인할 수 있었다. 이는 400도 이상 온도 증가 시 2차 핵생성 밀도 증가로 인해 결정성이 저하된다고 생각된다.