• Transactions on Electrical and Electronic Materials
• /
• 제10권2호
• /
• pp.44-48
• /
• 2009

A simulation study of a 10-bit two-stage DAC was done by using a conventional current switch cell. The DAC adopts the segmented architecture in order to reduce the circuit complexity and the die area. The 10-bit CMOS DAC was designed in 2 blocks, a unary cell matrix for 6 MSBs and a binary weighted array for 4 LSBs, for fabrication in a 0.35-${\mu}m$ CMOS process. To cancel the accumulation of errors in each current cell, a symmetrical switching sequence is applied in the unary cell matrix for 6 MSBs. To ensure high-speed operation, a decoding circuit with one stage latch and a cascode current source were developed. Simulations show that the maximum power consumption of the 10-bit DAC is 74 mW with a sampling frequency of 100 MHz.

• 반도체디스플레이기술학회지
• /
• 제14권1호
• /
• pp.27-30
• /
• 2015

SiC based Schottky barrier diodes were prepared by using the facing targets sputtering method. In this research, 4H-SiC polytypes of SiC were adopted and Molybdenum, Titanium was employed as the Schottky metal of the metal-semiconductor contacts. Both structures showed the rectifying nature in their forward and reverse J-V characteristic curve and the ideality factors calculated from these plots that were close to unity were represented the nearly ideal behavior. Difference of Schottky barrier height between prepared devices was also corresponding with the electrical characteristics of themselves. Therefore the suitability of the facing targets sputtering method for fabrication of Schottky diodes could be suggested from these results.

• 대한전자공학회:학술대회논문집
• /
• 대한전자공학회 1998년도 추계종합학술대회 논문집
• /
• pp.601-604
• /
• 1998

NOX detecting gas sensors using TiO2 doped tungsten oxide semiconductor were prepared and their electrical and sensing characteristics have been investigated. In normal air condition, the sensors of WO3, TiO2 doped WO3 show grain boundary heights of 0.34 eV, 0.25 eV, respectively. The grain boundary barrier energy variation was increased by doping TiO2 into large variation of resistance to NOX gases. And doping the TiO2 4 wt.%, the particle size of WO3 polycrystal films showed higher sensitivity and better sorption characteristics to NOX gas than the pure WO3 films material in air at operating temperature of $350^{\circ}C.$ The TiO2 doped WO3 semiconductor gas sensor shows nano-sized particle size and good sensitivity to sub-ppm concentration of NOX.

• 전력전자학회:학술대회논문집
• /
• 전력전자학회 2003년도 춘계전력전자학술대회 논문집(1)
• /
• pp.125-127
• /
• 2003

Lateral MCT(MOS-controlled thyristor)소자의 전기 적 특성 Parameters의 변화에 따른 스위칭 특성을 조사하였다. 제안된 Lateral 구조의 MCT는 채널과 drift영역의 제작과정이 간편하여 ON저항이 작으면서, 대전류용인 전력소자의 제작이 가능할 것으로 사료되는데, SPICE와 MEDICI 시뮬레이션을 이용하여 drift 저항, transit time및 불순물 농도 분포에 따른 전기적 특성을 알아보았다. 불순물의 농도와 채널길이의 변수에 의한 소자의 저항을 변화시켜 U 특성과 주파수 특성을 조사하였는데, 저항이 커질수록 turn-off 시간과 ON 저항은 증가함을 나타냈다.

• Transactions on Electrical and Electronic Materials
• /
• 제14권6호
• /
• pp.304-307
• /
• 2013

Reverse engineering of semiconductor devices utilizes delayering processes, in order to identify how the interconnection lines are stacked over transistor gates. Cu metal has been used in recent fabrication technologies, and de-processes becomes more difficult with the shrinking device dimensions. In this article, reverse engineering technologies to reveal the Cu interconnection lines and Cu via-plugs embedded in dielectric layers are investigated. Stacked dielectric layers are removed by $CF_4$ plasma etching, then the exposed planar Cu metal lines and via-plugs are selectively delineated by wet chemical solution, instead of the commonly used plasma-based dry etch. As a result, we have been successful in extracting the layouts of multiple layers within a system IC, and this technique can be applicable to other logic IC, analog IC, and CMOS IC, etc.

• 산업공학
• /
• 제17권spc호
• /
• pp.131-140
• /
• 2004

The purpose of this paper is to develop and show the efficiency of the URL(Unload Request Logic) and LRL(Load Request Logic) of the dispatcher in the Fab(Fabrication) Manufacturing Execution System. These logics are the core procedures which control the material(wafer and glass substrate) flow efficiently in the semiconductor and LCD fab considering inter-bay as well as intra-bay material flow. We use the present and future status information of the system by look-ahead and the information about the future transportation schedule of Automated Guided Vehicles. The simulation results show that the URL and LRL presented in this paper reduce the average lead time, average and maximum WIP level, and the average available AGV waiting time.

• 대한전기학회:학술대회논문집
• /
• 대한전기학회 1987년도 전기.전자공학 학술대회 논문집(II)
• /
• pp.1221-1224
• /
• 1987

In this paper, we had designed and fabricated the integrated circuit of AM tuner system for car. The very important characteristics of this system need very good sensitivity, selectivity and very strong automatic gain control function. In this system we had designed, maximum sensitivity is about 21dBu, selectivity above 40dB, AGC range above 80dB, etc. We had fabricated this IC using SST standard linear process.

• 반도체디스플레이기술학회지
• /
• 제5권2호
• /
• pp.1-5
• /
• 2006

The GaN thin film on the 8 periods InGaN/GaN multi-quantum well structure was grown on the sapphire substrate using metal-organic chemical vapor deposition. The nano-scaled triangular-lattice holes with the diameter of 150 nm were patterned on a polymethylmethacrylate blocking film using an electron beam nano-lithography system. The thin slab and two-dimensional photonic crystals with the thickness of 28 nm were fabricated on the GaN layer for the blue light diffraction sources. The photonic crystal with the lattice parameter of 460 nm enhances spectral intensity of photoluminescence indicating that the photonic crystals provides the source of nano-diffraction for the blue light of the 450-nm wavelength.

• 전자공학회논문지D
• /
• 제34D권5호
• /
• pp.61-66
• /
• 1997

In this paper we report the fabrication of an InGaAs metal-semiconductor-metal (MSM) photodiode(PD) which an InAlAs barrier enhancement layer that has very low dark current and high speed chracteristics. The detector using Cr/Au schottky metal fingers with 4um spacing on a large active area of 300*300um$^{2}$ offers a low dark current of 38nA at 10V, a low capacitance of 0.8pF, and a high 3-dB bandwidth of 2.4 GHz. To our knowledge, these characteristics are better than any previously published results obtained from large area InGaAs MSM PD's. The RC equivalent model and frequency domain current response model considering transit time were also used to analyze the frequency characteristic of the fabricated device.

• 한국전기전자재료학회:학술대회논문집
• /
• 한국전기전자재료학회 2004년도 추계학술대회 논문집 Vol.17
• /
• pp.260-263
• /
• 2004

During the last few years, there have been many efforts on the fabrication of electronic and optical devices based on semiconductor nanowires. Room-temperature ultraviolet lasing in GaN nanowire, ultraviolet light sensing in ZnO nanowire, and dramatically improved hall mobility in Si nanowire have been demonstrated in this article. The studies on semiconductor nanowire based electronic and optical device is reviewed.