• 한국전기전자재료학회논문지
• /
• 제27권9호
• /
• pp.582-588
• /
• 2014

3 mol% Co-added $Ni(OH)_2$ fine powders, which showed ${\beta}$-phase, as positive electrode materials have been fabricated using $NiSO_4{\cdot}6H_2O$ aqueous solution by ultrasonic spray-chemical precipitation and subsequent hydrothermal method, and sheet-like Ni nanopowder was fabricated by mechano-chemical reduction method. The addition effects of the sheet-like Ni nanopowder on the electrochemical properties of the positive electrode in Ni-Zn Redox flow battery were investigated. Impedance spectroscopy revealed that the addition of the sheet-like Ni nanopowder resulted in decrease in the electrical resistivity; 10 wt.% addition reduced the electrical properties by a fifth. Cyclic voltammetry showed the addition of the sheet-like Ni nanopowder resulted in decrease in the potential difference of oxidation and reduction; this means the increase in the reversability for electrode reduction. Charge/discharge measurement confirmed that the addition of the sheet-like Ni nanopowder resulted in the increase in the discharge efficiency.

• 대한전기학회논문지:전기물성ㆍ응용부문C
• /
• 제53권10호
• /
• pp.495-499
• /
• 2004

Characteristics of ohmic Ni/Si/Ni contacts to n-type 4H-SiC are investigated systematically. The ohmic contacts were formed by annealing Ni/Si/Ni sputtered sequentially The annealings were performed at 950℃ using RTP in vacuum ambient and N₂ ambient, respectively. The specific contact resistivity(p/sub c/), sheet resistance(R/sub s/), contact resistance (R/sub c/) transfer length(L/sub T/) were calculated from resistance(R/sub T/) versus contact spacing(d) measurements obtained from TLM(transmission line method) structure. While the resulting measurement values of sample annealed at vacuum ambient were p/sub c/ = 3.8×10/sup -5/Ω㎠, R/sub c/ = 4.9 Ω and R/sub T/ = 9.8 Ω, those of sample annealed at N₂ ambient were p/sub c/ = 2.29×10/sup -4/Ω㎠, R/sub c/ = 12.9 Ω and R/sub T/ = 25.8 Ω. The physical properties of contacts were examined using XRD 3nd AES. The results showed that nickel silicide was formed on SiC and Ni was migrated into SiC. This result indicates that Ni/Si/Ni ohmic contact would be useful in high performance electronic devices.

• 한국진공학회:학술대회논문집
• /
• 한국진공학회 2014년도 제46회 동계 정기학술대회 초록집
• /
• pp.342.1-342.1
• /
• 2014

The electrical, optical and structural properties of Ti doped $In_2O_3$ (TIO) ohmic contacts to p-type GaN were investigated using linear facing target sputtering (LFTS) system. Sheet resistance and resistivity of TIO films are decreased with increasing rapid thermal annealing (RTA) temperature. Although the $400^{\circ}C$ and $500^{\circ}C$ annealed samples showed rectifying behavior, the $600^{\circ}C$ and $700^{\circ}C$ annealed samples showed linear I-V characteristics indicative of the formation of an ohmic contact between TIO and p-GaN. The annealing of the contact at $700^{\circ}C$ resulted in the lowest specific contact resistivity of $9.5{\times}10^{-4}{\Omega}cm^2$. Based on XPS depth profiling and synchrotron X-ray scattering analysis, we suggested a possible mechanism to explain the annealing dependence of the properties of TIO layer on rapid thermal annealing temperature.

• 한국전기전자재료학회:학술대회논문집
• /
• 한국전기전자재료학회 1995년도 추계학술대회 논문집
• /
• pp.244-247
• /
• 1995

Physical, electrical and optical properties of Aluminum(Al) thin films were investigated in order to establish the optimum sputtering parameters in mirror reflection films. Al. thin films deposited on corning glass substrate by DC magnetron sputtering were grown as a variation of the input power, operation pressure and deposition time. The properties of the Al thin films have been discussed by deposition rate, SEM, XRD, sheet resistivity, resistivity and reflectance. Al thin films were obtained at the deposition conditions as follows: operating pressure, 3 mtorr; DC input power desnsitiy, 3W/$\textrm{cm}^2$.

• 한국전기전자재료학회:학술대회논문집
• /
• 한국전기전자재료학회 2003년도 하계학술대회 논문집 Vol.4 No.1
• /
• pp.267-269
• /
• 2003

반도체 웨이퍼 및 각종 박막의 면/비저항(sheet/resistivity resistance)의 측정에 비교적 간단히 측정할 수 있고 측정정확도가 높은 4탐침(four-point probe)방법이 널리 사용되고 있다 또한 4탐침 측정방법은 높은 분해능의 contour map작성과 ion implantation의 doping accuracy 및 doping uniformity의 측정에도 사용된다. 최근 재료의 소형, 박막화 경향으로 볼 때 정확한 비저항 측정의 필요성이 요구되고 있으며 이에 따라 4탐침 측정기술인 single 및 dual configuration method로 실리콘 웨이퍼에 대한 비저항의 측정 정확도를 고찰한 결과 dual configuration 측정방법이 single configuration측정 방법에 비하여 정밀 정확도가 더 좋은 것으로 고찰되었다.

• 열처리공학회지
• /
• 제25권2호
• /
• pp.85-89
• /
• 2012

Transparent conductive ZnO/Ag/ZnO (ZAZ) multilayer films were deposited by Radio frequency (RF) magnetron sputtering and direct current (DC) magnetron sputtering. The effects of post deposition vacuum annealing temperature on the structural, electrical and optical properties of the ZAZ multilayer films were investigated. The thickness of ZAZ films is kept constant at ZnO 50 nm/Ag 5nm/ZnO 45 nm, while the vacuum annealing temperatures were varied from 200 and $400^{\circ}C$, respectively. As-deposited ZAZ films exhibit a sheet resistance of $6.1{\Omega}/{\Box}$ and optical transmittance of 72.7%. By increasing annealing temperature to $200^{\circ}C$, the resistivity decreased to as low as $5.3{\Omega}/{\Box}$ and optical transmittance also increased to as high as 82.1%. Post-deposition annealing of ZAZ multilayer films lead to considerably lower electrical resistivity and higher optical transparency, simultaneously by increased crystallization of the films.

• 한국재료학회지
• /
• 제21권5호
• /
• pp.255-262
• /
• 2011

This paper has relatively high technical standard and experimental skill. The fabrication of TCO film with high transparency, low resistance and low chromaticity require exact control of several competing factors. This paper has resolved these problems reasonably well, thus recommended for publication. Indium tin oxide(ITO) thin films were by D.C. magnetron roll-to-roll sputter system utilizing ITO and $SiO_2$ targets of ITO and $SiO_2$. In this experiment, the effect of D.C. power, winding speed, and oxygen flow rate on electrical and optical properties of ITO thin films were investigated from the view point of sheet resistance, transmittance, and chromaticity($b^*$). The deposition of $SiO_2$ was performed with RF power of 400W, Ar gas of 50 sccm and the deposition of ITO, DC power of 600W, Ar gas of 50 sccm, $O^2$ gas of 0.2 sccm, and winding speed of 0.56m/min. High quality ITO thin films without $SiO_2$ layer had chromaticity of 2.87, sheet resistivity of 400 ohm/square, and transmittance of 88% and $SiO_2$-doped ITO Thin film with chromaticity of 2.01, sheet resistivity of 709 ohm/square, and transmittance of more than 90% were obtained. As a result, $SiO_2$ was coated on PET before deposition of ITO, their chromaticity($b^*$) and transmittance were better than previous results of ITO films. These results show that coating of $SiO_2$ induced arising chromaticity($b^*$) and transmittance. If the thickness of $SiO_2$ is controlled, sheet resistance value of ITO film will be expected to be better for touch screen. A four point probe and spectrophotometer are used to investigate the properties of ITO thin films.

• 대한전기학회:학술대회논문집
• /
• 대한전기학회 1991년도 하계학술대회 논문집
• /
• pp.322-325
• /
• 1991

An induction type small size electrostatic actor has been fabricated and tested using different rotor dielectric sheet type materials and 3 phase ac various frequencies ans volatages. It's maximum no-load speed was about 2800rpm at the applied voltage of 3030V and frequency of 47Hz for the rotor material of polypropylene sheet. The motor speed was increased linearly by increasing with an applied volatage and frequency, and it also influenced greatly by the electrical properties of rotor dielectric material of relative dielectric constant, resistivity and relaxtion time

• 대한전자공학회논문지
• /
• 제27권12호
• /
• pp.1852-1858
• /
• 1990

The sheet resistance and thickness of Ti-Silicides treated RTA at 600, 700, 800\ulcorner was measured with amount of BF2 implanted in Si substrate. And the profile of BF2 was studied by SIMS. The formation of TiSi2 starts at 700\ulcorner. The Ti-Silicides almost consist of TiSi2 and have a low resistivity about 16列 cm at 800\ulcorner. The sheet resistances of Ti-silicides increase and thicknesses of it decrease with increasing dose of BF2. Considering the results of SIMS and the thickness of native oxide, the decrease of thickness of Silicides chiefly results from the increase of native oxide thickness with increasing dopants.

• 한국전기전자재료학회:학술대회논문집
• /
• 한국전기전자재료학회 2002년도 하계학술대회 논문집
• /
• pp.318-321
• /
• 2002

This paper presents a proper condition to achieve high conversion efficiency using PC1D simulator on sri-crystalline Si solar cells. Various efficiency influencing parameters such as rear surface recombination velocity and minority carrier diffusion length in the base region, front surface recombination velocity, junction depth and doping concentration in the Emitter layer, BSF thickness and doping concentration were investigated. Optimized cell parameters were given as rear surface recombination of 1000 cm/s, minority carrier diffusion length in the base region 200 $\mu\textrm{m}$, front surface recombination velocity 100 cm/s, sheet resistivity of emitter layer 100 Ω/$\square$, BSF thickness 5 $\mu\textrm{m}$, doping concentration 5${\times}$10$\^$19/ cm$\^$-3/. Among the investigated variables, we learn that a diffusion length of base layer acts as a key factor to achieve conversion efficiency higher than 19 %.