• 한국군사과학기술학회지
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• 제12권4호
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• pp.483-490
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• 2009

In this paper, a novel low-damage silicon nitride passivation for 100nm InAlAs/InGaAs MHEMTs has been developed using remote ICPCVD. The silicon nitride deposited by ICPCVD showed higher quality, higher density, and lower hydrogen concentration than those of silicon nitride deposited by PECVD. In particular, we successfully minimized the plasma damage by separating the silicon nitride deposition region remotely from ICP generation region, typically with distance of 34cm. The silicon nitride passivation with remote ICPCVD has been successfully demonstrated on GaAs MHEMTs with minimized damage. The passivated devices showed considerable improvement in DC characteristics and also exhibited excellent RF characteristics($f_T$of 200GHz).The devices with remote ICPCVD passivation of 50nm silicon nitride exhibited 22% improvement(535mS/mm to 654mS/mm) of a maximum extrinsic transconductance($g_{m.max}$) and 20% improvement(551mA/mm to 662mA/mm) of a maximum saturation drain current ($I_{DS.max}$) compared to those of unpassivated ones, respectively. The results achieved in this work demonstrate that remote ICPCVD is a suitable candidate for the next-generation MHEMT passivation technique.

• 한국표면공학회지
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• 제32권3호
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• pp.239-243
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• 1999

At Present, 200mm wafer technology is being applied for commercial fabrications of 64, 128, and 256 M DRAM devices, and 300mm technology will be evolved for 1G DRAM devices in the early 21th century, recognizing limitations of several process technologies. In particular recognition has been realized in harmful effects of surface contamination of trace metals introduced during devicing processes. Such a guide line for surface metal contamination has been proposed as 1E9 and 1E10 atoms/$\textrm{cm}^2$ of individual metal contamination for wafering and devicing of 1G DRAM, respectively, and so its measurement limit should be at least 1E8 atoms/$\textrm{cm}^2$. The detection limit of present measurement systems is 2E9 atoms/$\textrm{cm}^2$ obtainable with TRXFA(Total Reflection X-Ray Fluorescence Analysis). TRXFA is nondestructive and the simplest in terms of operation, and it maps the whole wafer surfaces but needs detection improvement. X-Ray intensity produced with synchrotron accelerator is much higher than that of conventional X-ray sources by order of 4-5 magnitudes. Hence theoretically its reactivity with silicon surfaces is expected to be much higher than the conventional one, realizing improvement of detection limit. X-ray produced with synchrotron accelerator is illuminated at a very low angle with silicon wafer surfaces such as 0.1 degree and reflects totally. Hence informations only from surface can be collected and utilized without overlapping with bulk informations. This study shows the total reflection phenomenon and quantitative improvement of detection limit for metallic contamination. It is confirmed that synchrotron X-ray can be a very promising alternative for realizing improvement of detection limit for the next generation devices.

• 대한수의학회지
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• 제55권2호
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• pp.97-103
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• 2015

In this study, the Korean veterinary medical devices management system was evaluated relative to systems in the USA, EU, and Japan. Veterinary medical devices are regulated in Korea based on the Medical Appliance Act of 1997. This was initially supervised by the Ministry of Agriculture, Food and Rural Affairs and Korea Animal Health Products Association, and subsequently by the Animal and Plant Quarantine Agency (QIA) in 2000. These devices were classified approximately 1,400 categories as instruments, supplies, artificial insemination apparatus, and other categories. Each of these devices was assigned to four regulatory grades by the QIA in 2007. The ranking system for veterinary medical devices was implemented in 2014 with 820 products from 162 companies registered by that year. However, in vitro diagnostic devices (IVDDs) for animals were managed as medical devices and biological medicine. In vitro diagnostic reagents for treating infection diseases are not subjected to either a classification or grading system. Veterinary medical devices are currently exempt from good manufacturing practices (GMP) and device tracking requirements. Due to gradual growth of the domestic veterinary medical devices market since 2008, regulation of these devices should be improved with re-examination of IVDDs and GMP certification for the effective operating system.

• 동의생리병리학회지
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• 제28권6호
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• pp.662-667
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• 2014

The purpose of this clinical study is to develop structured clinical trial protocol and guideline for improvement of safety, useful and effective of pulse diagnosis devices. As a first step, papers on pulse diagnosis and pulse diagnosis devices from 2001 and 2013 were systematically reviewed. In the next step, we have collected the opinions from the specialists, companies, and statistician in pulse diagnosis to evaluate the current condition, the state and problem of domestic clinical trial cases of pulse diagnosis device. And we have to created protocol and case report form (CRF) in regards to site condition and characteristics of pulse diagnosis devices, and showed the guideline of eligibility criteria, operation process, investigation items, evaluation items and so on. This clinical protocol will become a basic information for a researcher in designing or performing a clinical study of pulse diagnosis devices, and be used as a useful material during acquisition of good clinical data. Furthermore, we hope to enhance the invigoration of pulse diagnosis clinical trials and the performance improvement of pulse diagnosis devices.

• 대한의용생체공학회:의공학회지
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• 제44권5호
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• pp.315-323
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• 2023

The objective of this study is to identify the selective application targets for reporting on details of supply of class 1 and 2 medical devices as part of the improvement of the reports on details of supply of medical device system, and to analyze its effectiveness. Therapeutic materials covered by health insurance and secondhand medical devices were chosen based on the transparency of health insurance coverage and the management of medical device distribution. As a result, approximately 85% of groups can be excluded from the reporting requirements compared to reporting all items under Class 1 and 2 medical devices. This is expected to enhance the efficiency of supply reporting tasks. Additionally, the information on supply details managed by the regulatory authority can be utilized for statistical analysis and periodic monitoring, serving as fundamental data for the development of medical device-related policies and research in the field of medical devices.

• 한국분무공학회지
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• 제19권2호
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• pp.75-81
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• 2014

Swirl flow in the gun type burner has a decisive effect on the stabilization of the flame, improvement of the combustion efficiency, and also a reduction of NOx. This swirl flow is created by the spinner which is inside the airtube that guide the combustion air. Gun type burner has generally the inner devices composed nozzle adapter, spark gap ignitor, and spinner. These inner components change the air flow behavior passing through air tube. Meanwhile, turbulent characteristics of this air flow are important to understand the combustion phenomena in the gun type burner, because the mixture of fuel and air are depended on. However, nearly all of the studies have been analyzed the turbulent flow of simplified combustion formation without the inner devices. So, this study conducted the measurement using by hot-wire anemometer and analyzed turbulent flow characteristics of the swirl flow discharged from the air tube with inner devices. Turbulence characteristics come up in this study were turbulence intensity, kinetic energy and shear stress of the air flow with the change of the distance of axial direction from the exit of the air tube.

• 센서학회지
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• 제31권4호
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• pp.238-243
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• 2022

In this study, a pyrene-core single molecule with amino (-NH₂) functional group material was hybridized using ZnO quantum dots (QDs). The suppressed performance of the 1-aminopyrene (1-PyNH₂) single molecule as an emissive layer (EML) in light-emitting diodes (LEDs) was exploited by adopting the ZnO@1-PyNH₂ core-shell structure. Unlike pristine 1-PyNH₂ molecules, the ZnO@1-PyNH₂ hybrid QDs formed energy proximity levels that enabled charge transfer. This result can be interpreted as an improvement in surface roughness. The uniform and homogeneous EML alleviates dark-spot degradation. Moreover, LEDs with the ITO/PEDOT:PSS/TFB/EML/TPBi/LiF/Al configuration were fabricated to evaluate the performance of two emissive materials, where pristine-1-PyNH₂ molecules and ZnO@1-PyNH₂ QDs were used as the EML materials to verify the improvement in electrical characteristics. The ZnO@1-PyNH₂ LEDs exhibited blue luminescence at 443 nm (FWHM = 49 nm), with a turn-on voltage of 4 V, maximum luminance of 1500 cd/m², maximum luminous efficiency of 0.66 cd/A, and power efficiency of 0.41 lm/W.

• Journal of Power Electronics
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• 제18권4호
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• pp.985-996
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• 2018

The implementation and performance evaluation of an interleaved boundary conduction mode (BCM) boost power factor correction (PFC) converter is presented in this paper by employing three wide band-gap switching devices: a super junction silicon (Si) MOSFET, a silicon carbide (SiC) MOSFET and a gallium nitride (GaN) high electron mobility transistor (HEMT). The practical considerations for adopting wide band-gap switching devices to BCM boost PFC converters are also addressed. These considerations include the gate drive circuit design and the PCB layout technique for the reliable and efficient operation of a GaN HEMT. In this paper it will be shown that the GaN HEMT exhibits the superior switching characteristics and pronounces its merits at high-frequency operations. The efficiency improvement with the GaN HEMT and its application potentials for high power density/low profile BCM boost PFC converters are demonstrated.

• 에너지공학
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• 제22권1호
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• pp.58-81
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• 2013

탄화규소(SiC)나 질화갈륨(GaN)과 와이드갭 반도체를 이용한 전력소자의 생산기술이 크게 발전하여 그간 널리 사용되어 온 실리콘(Si) 전력소자와 비교하여 작동전압, 스위칭 속도 및 on-저항 등이 크게 향상되어 몇 개 기업은 제품화를 시작하였다. 내압 등 기술적 과제 등을극복하여 산업화를 하고자하는 움직임을 소개하고 아울러 연구동향도 분석한다.

• 한국전기전자재료학회논문지
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• 제25권4호
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• pp.266-269
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• 2012

The most recently IGBT (insulated gate bipolar mode transistor) devices are in the most current conduction capable devices and designed to the big switching power device. Use this number of the devices are need to high voltage and low on-state voltage drop. And then in this paper design of field stop IGBT is insert N buffer layer structure in NPT planar IGBT and optimization design of field stop IGBT and trench field stop IGBT, both devices have a comparative analysis and reflection of the electrical characteristics. As a simulation result, trench field stop IGBT is electrical characteristics better than field stop IGBT.