• 전자공학회논문지A
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• 제32A권8호
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• pp.126-132
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• 1995

The electrical stress of short channel polycrystalline silicon (poly-Si) thin film transistor (TFT) has been investigated. The device characteristics of short channel poly-Si TFT with 5$\mu$m channel length has been observed to be significantly degraded such as a large shift in threshold voltage and asymmetric phenomena after the electrical stress. The dominant degradation mechanism in long channel poly-Si TFT's with 10$\mu$m and 20$\mu$m channel length respectively is charage trappling in gate oxide while that in short channel device with 5.mu.m channel length is defect creation in active poly-Si layer. We propose that the increased defect density within depletion region near drain junction due to high electric field which could be evidenced by kink effect, constitutes the important reason for this significant degradation in short channel poly-Si TFT. The proposed model is verified by comparing the amounts of the defect creation and the charge trapping from the strechout voltage.

• JSTS:Journal of Semiconductor Technology and Science
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• 제15권2호
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• pp.249-254
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• 2015

Solution-derived amorphous indium-gallium-zinc oxide (a-IGZO) thin-film-transistor (TFTs) were developed using a microwave irradiation treatment at low process temperature below $300^{\circ}C$. Compared to conventional furnace-annealing, the a-IGZO TFTs annealed by microwave irradiation exhibited better electrical characteristics in terms of field effect mobility, SS, and on/off current ratio, although the annealing temperature of microwave irradiation is much lower than that of furnace annealing. The microwave irradiated TFTs showed a smaller $V_{th}$ shift under the positive gate bias stress (PGBS) and negative gate bias stress (NGBS) tests owing to a lower ratio of oxygen vacancies, surface absorbed oxygen molecules, and reduced interface trapping in a-IGZO. Therefore, microwave irradiation is very promising to low-temperature process.

• 한국진공학회:학술대회논문집
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• 한국진공학회 2014년도 제46회 동계 정기학술대회 초록집
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• pp.238.1-238.1
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• 2014

이번 연구는 system-on-panel에 적용하기 위한 비휘발성 메모리의 메모리 윈도우 특성 향상에 관한 연구이다. 이를 위해 SiO2/SiNX/SiOXNY의 메모리 구조를 이용하였으며, 채널층으로 투명한 비정질 인듐-주석-아연-산화물을 이용하였다. N형 물질의 특성인 수많은 전자로 인해 erasing의 어려움이 발생하는데 이는 빛과 전압의 동시 인가로 해결하였다. 전하트랩층은 비휘발성 메모리에서 가장 널리 이용되는 질화막을 이용하였으며, SiH4과 NH3의 비율은 8대 1에서 1대 2까지 이용하였다. 이번 연구에서 SiH4과 NH3의 비율이 2대 1일 때 쓰기 전압 +13V와 지우기 전압 -6V에서 약 3.7V의 높은 메모리 윈도우를 얻을 수 있었다.

• 대한전기학회:학술대회논문집
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• 대한전기학회 1990년도 하계학술대회 논문집
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• pp.243-246
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• 1990

The theory was analyzed and the computer program was developed for simulation about ceramic filter in the state of the one-strip electrode using the energy trapping effect. They were fabricated using the PZT-4 specimen. Each of the average differances of the resonant point and bandwidth between by the theoretical calculations and by experiment results was 5.6[%] and 3.72[%], and it is considered that this differance is originated from the high temperature and stress during the process that the ceramic filter was fabricated It is considered that the one-strip ceramic filter having a wanted characteristics and the lowest differance is fabricated easily by means of the simulation developed in this paper and the fabrication methods.

• Current Photovoltaic Research
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• 제2권2호
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• pp.73-77
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• 2014

To investigate the effect of metal back-reflective layers (MBLs) on the performance of GaAs solar cells, we fabricated GaAs solar cells on Al and Ag metal layers using the transfer printing technique. We also investigated the effect of MBL texturing on the performance of transfer printed GaAs solar cells. Transfer printed solar cells with MBLs exhibited improved photovoltaic performance compared to solar cells without MBLs due to light trapping. We demonstrated GaAs solar cells with MBLs on a flexible substrate and performed systematic bending tests. All the measured characteristics of solar cells showed little change in performance.

• 한국자동차공학회논문집
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• 제5권2호
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• pp.69-79
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• 1997

This paper deals with the measurement and analysis on the scavenging performance of the oppet-valve type two-stroke engine with different shroud system. The scavenging flow characteristics is investigated by flow visualization under steady condition, in which a dye is introduced into single-cycle method using the difference of specific gravity between two working fluids is used to evaluate the scavenging efficiency and the trapping efficiency. The 90° shroud system was found to be the highest efficiency system through both flow visualization and single-cycle test, as well as the shroud system to generally be efficient for reducing a short-circuiting flow during scavenging process in a two-stoke engine.

• 대한전기학회:학술대회논문집
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• 대한전기학회 1987년도 정기총회 및 창립40주년기념 학술대회 학회본부
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• pp.242-244
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• 1987

Using the energy trapping theory and the acoustic coupling theory. the Bandpass filter(center frequency = 10.7 MHz) of the fundamental thickness mode was made from the composition of $Pb_{0.96}Sr_{0.04}(Zr_{0.53}Ti_{0.47})O_3$+ 1wt% $Fe_2O_3$. Also, in the double mode monolithic filter, It was observed that as decreasing the size of the electrodes, or shortening the gap between two electrodes, the percent frequency separation was increased. Based on these. a 10.7 MHz uniwafer filter was made having the characteristics that bandwidth was 700 KHz and the percent frequency separation was 6 [dB] and selectivity was 29 [dB], end spurious response was 24 [dB] and insertion loss was 7 [dB].

• International Journal of Naval Architecture and Ocean Engineering
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• 제4권4호
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• pp.437-446
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• 2012

An ocean buoy energy farm is considered for Green energy generation and delivery to small towns along the Korean coast. The present study presents that the floating buoy-type energy farm appears to be sufficiently feasible for trapping more energy compared to affixed cylinder duck array. It is also seen from the numerical results that the resonated waves between spaced buoys are further trapped by floating buoy motion.Our numerical study is analyzed by a plane-wave approximation, in which evanescent mode effects are included in a modified mild-slope equation based on the scattering characteristics for a single buoy.

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 2000년도 하계학술대회 논문집
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• pp.82-85
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• 2000

The less sensitive structure to the surface effect has been presented utiliting an undoped GaAs layer on the n-GaAs channel. The undoped layer has been found to be effective to supress the frequency dispersion phenomena caused by a surface trapping effect and to raise the MESFET's performance. The gate structure, with an undoped layer underneath the gate metal has been found to be effective to improve the breakdown voltage. GaAs MESFETS with different physical structures are fabricated and DC characteristics are measued. GaAs MESFET's are fabricated on epi-wafers which have an undoped GaAs layer in between n+ and n GaAs layers grown by MBE.

• 한국전기전자재료학회논문지
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• 제17권7호
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• pp.788-792
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• 2004

The Electromagnetic properties in BiPbSrCaCuO superconductor was studied. In the measurement of current-voltage characteristics, a voltage across the superconducting sample was observed on applying an external magnetic field. The voltage continues to appear the removal of the magnetic field. The appearance of the voltage is ascribed to the trapping of magnetic flux. Depanding on the direction of appied magnetic flux less than $2.5\times{10}^-5$ T, the voltage in the magnetized sample increases or decreases. It is considered that mechanism of voltage occurrence can be explained by applying filament model.