• 반도체디스플레이기술학회지
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• 제12권1호
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• pp.41-45
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• 2013

IGZO transparent conductive thin films were widely used as transparent electrode of optoelectronic devices. We have studied the optical and electrical properties of IGZO thin films. The IGZO thin films were deposited on the corning 1737 glass by RF magnetron sputtering method. The RF power in sputtering process was varied as 25, 50, 75and 100 W, respectively. All of the thin films transmittance in the visible range was above 85%. XRD analysis showed that amorphous structure of the thin films without any peak. The thin films were electrically characterized by high mobility above $13.4cm^2/V{\cdot}s$, $7.0{\times}10^{19}cm^{-3}$ high carrier concentration and $6{\times}10^{-3}{\Omega}-cm$ low resistivity. By the studies we found that IGZO transparent thin film can be used as transparent electrodes in electronic devices.

• Journal of Electrical Engineering and Technology
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• 제13권1호
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• pp.387-392
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• 2018

Static characteristics of SiC (silicon carbide) lateral p-i-n diodes implemented on semi-insulating substrate without an epitaxial layer are inVestigated. On-axis SiC HPSI (high purity semi-insulating) and VDSI (Vanadium doped semi-insulating) substrates are used to fabricate the lateral p-i-n diode. The space between anode and cathode ($L_{AC}$) is Varied from 5 to $20{\mu}m$ to inVestigate the effect of intrinsic-region length on static characteristics. Maximum breakdown Voltages of HPSI and VDSI are 1117 and 841 V at $L_{AC}=20{\mu}m$, respectiVely. Due to the doped Vanadium ions in VDSI substrate, diffusion length of carriers in the VDSI substrate is less than that of the HPSI substrate. A forward Voltage drop of the diode implemented on VDSI substrate is 12 V at the forward current of $1{\mu}A$, which is higher than 2.5 V of the diode implemented on HPSI substrate.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2006년도 제37회 하계학술대회 논문집 C
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• pp.1351-1352
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• 2006

In this paper, the impedance properties of degraded thyristor with heat and voltage were presented. As degraded thyristor, 8 thyristors with each other different reverse blocking voltage used. Its impedance and resistance properties were measured from frequency 100Hz to 10MHz applied with bias voltage from 0V to 40V. As a result, at low frequency region, that is, at the frequency 100-10kHz, the abrupt increasement of its capacitance was confirmed. And also, at high frequency region, the capacitance peak move toward low frequency in the region of frequency 4 - 6MHz as degradation of thyristor.

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 2004년도 하계학술대회 논문집 Vol.5 No.1
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• pp.365-368
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• 2004

Charge compensation effects in multi-resurf structure make possible to obtain high breakdown volatage and low on-resistance in vertical MOSFET. In this paper, electrical characteristics of the vertical MOSFET with multi epitaxial layer is presented. Proposed device has n and p-pillar for obtaining the charge compensation effects and The doping concentration each pillar is varied from $5{\times}10^{14}\;to\;1{\times}10^{16}/cm^3$. The thickness of the proposed device also varied from $400{\mu}m\;to\;500{\mu}m$. Due to the charge compensation effects, 4500V of breakdown voltage can be obtained.

• 설비공학논문집
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• 제22권11호
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• pp.760-766
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• 2010

Excessive heat occurs during semiconductor manufacturing process. Thus, precise control of temperature is required to maintain constant chamber-temperature and also wafer-temperature in the chamber. Compared to an industrial chiller, semiconductor chiller's power consumption is very high due to its continuous operation for a year. Considering the high power consumption, it is necessary to develop an energy efficient chiller by optimizing operation control. Therefore, in this study, a semiconductor chiller is experimentally investigated to suggest energy-saving direction by conducting load change, temperature rise and fall and control precision experiments. The experimental study shows the cooling capacity of dual-channel chiller rises over 30% comparing to the conventional chiller. The time and power consumption in the temperature rising experiment are 43 minutes and 8.4 kWh, respectively. The control precision is the same as ${\pm}1^{\circ}C$ at $0^{\circ}C$ in any cases. However, it appears that the dual channel's control precision improves to ${\pm}0.5^{\circ}C$ when the setting temperature is over $30^{\circ}C$.

• 반도체디스플레이기술학회지
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• 제11권2호
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• pp.85-91
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• 2012

In this paper, the large data processing and suitable FAT32 file system for industrial system using a PLC and CF memory was implemented. Most of PLC can't save the large data in user data memory. So it's required to the external devices of CF memory or NAND flash memory. The CF memory is used in order to save the large data of PLC system. The file system using the CF memory is NTFS, FAT, and FAT32 system to configure in various ways. Typically, the file system which is widely used in industrial data storage has been implemented as modified FAT32. The conventional FAT 32 file system was not possible for multiple writing and high speed data accessing. The proposed file system was implemented by the large data processing module can be handled that the files are copied at the 40 bytes for 1msec speed logging and creating 8 files at the same time. In a sudden power failure, high reliability was obtained that the problem was solved using a power fail monitor and the non-volatile random-access memory (NVSRAM). The implemented large data processing system was applied the modified file system as FAT32 and the good performance and high reliability was showed.

• 조명전기설비학회논문지
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• 제16권1호
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• pp.35-43
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• 2002

새로운 형태의 고체 상태의 대전력, 고속전자장치인 광전도 전력스위치(PCPS)의 개발과 대전력 및 고전압 상태하에서 광전도 전력스위치의 고전계 동작특성을 규명하기 위해서 많은 연구가 행해지고 있다. 그러나 표면 섬락 현상이 확실하고 효과 있는 고속, 고압스위칭 소자의 실현을 방해하고 있다. 이러한 연면방전의 물리적 현상의 명백한 이해는 새로운 기술과 소자구성을 발전시키는데 매우 중요할 뿐 아니라, 고전계·고전압에서의 동작특성을 향상시키는데 있어서도 특별한 의미를 가진다. 뿐만 아니라 고전계, 고전력 소자들을 안전하게 동작할 수 있게 하기 위해서도 필요하다. 연면방전 및 표면 절연파괴현상은 반도체 벌크 파괴 전계보다 훨씬 낮은 전계에서 적용되어 파괴된 모든 소자들에서 발생하기 때문에 이러한 문제를 해결하는 매우 실용적인 방법이 소자의 표면을 절연물로 페시베이션하는 것이다. 페시베이션된 소자들은 고전계에서 언페시페이션된 소자에 비해 매우 좋은 동작특성을 나타내므로, 본 논문에서는 페시베이션된 소자와 언페시베이션된 소자간의 I-E특성과 파괴 메커니즘을 규명하고 더 나아가 다중 페시베이션에 대한 몇몇 특성 값을 제시한다.

• 반도체디스플레이기술학회지
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• 제1권1호
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• pp.41-45
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• 2002

In modem manufacturing, new applations and technologies demand smaller, and functional devices to replace large systems. As miniaturization becomes a necessity, many companies are interested in small pumps for use in creating ultra-high vacuum, but past efforts to develop such systems have failed due to problems with vibration, stress, heat and power consumption. This paper shows analysis-based design techniques for high vacuum turbomolecular pump by finite element analysis.

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 2003년도 하계학술대회 논문집 Vol.4 No.1
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• pp.249-251
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• 2003

This paper discribes the analysis of the breakdown voltage characteristics of SOI LIGBT with dual epi-layer. In case of SOI LIGBT with dual epi-layer, if we used high doping concentration in epi-layer, we obtained higher breakdown voltage compared with typical device because of charge compensation effect, and we obtained low on-state resistivity characteristic in the same breakdown voltage. In this paper, we analyzed on-state and off-state characteristics of SOI LIGBT with dual epi-layer. Breakdown voltage of proposed LIGBT was shown 125V when $T_1=T_2=2.5{\mu}m$, $N_1=7{\times}10^{15}/cm^3$ and $N_2=3{\times}10^{15}/cm^3$, respectively Although we used high doping concentration and thin epi-layer thickness, breakdown voltage was increased compared with conventional devices.

• JSTS:Journal of Semiconductor Technology and Science
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• 제13권5호
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• pp.500-510
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• 2013

In this paper, a high-sensitivity low power photodetector using double gate (DG) MOSFET is proposed for the first time using change in subthreshold current under illumination as the sensitivity parameter. An analytical model for optically controlled double gate (DG) MOSFET under illumination is developed to demonstrate that it can be used as high sensitivity photodetector and simulation results are used to validate the analytical results. Sensitivity of the device is compared with conventional bulk MOSFET and results show that DG MOSFET has higher sensitivity over bulk MOSFET due to much lower dark current obtained in DG MOSFET because of its effective gate control. Impact of the silicon film thickness and gate stack engineering is also studied on sensitivity.