• 한국재료학회:학술대회논문집
• /
• 한국재료학회 1999년도 추계학술발표강연 및 논문개요집
• /
• pp.80-80
• /
• 1999

• 한국전기전자재료학회:학술대회논문집
• /
• 한국전기전자재료학회 1995년도 추계학술대회 논문집
• /
• pp.63-66
• /
• 1995

The ohmic characterization of Au/Te/Au/n-GaAs structure is investigated by the application of x-ray diffraction, scanning electron microscopy, Auger electron spectroscopy, the specific contact resistance and I-V measurement. Increasing the annealing temperature, the results of XRD measurement show the sharpening of the Au-Ga peak and the increasing of the intensity of Au peak due to the crystallization. At 400$^{\circ}C$, which is the ohmic onset point, Ga$_2$Te$_3$peak gets evident and GaAs regrowth peak appears for the samples annealed at 500$^{\circ}C$. The variation of shottky contact to ohmic contact is confirmed by the I-V curve transition. The specific contact resistance of 3.8x10$\^$-5/$\Omega$-$\textrm{cm}^2$ is obtained for the sample annealed at 500$^{\circ}C$ and above 600$^{\circ}C$ the specific contact resistance increased due to the decomposition of GaAs substrate.

• 대한전자공학회:학술대회논문집
• /
• 대한전자공학회 2001년도 하계종합학술대회 논문집(2)
• /
• pp.213-216
• /
• 2001

The use of a thin film of indium between the ITO and the $n^{+}$-InP contact layers for InP/InGaAs HPTs was studied without degrading its excellent optical transmittance properties. ITO/$n^{+}$-InP ohmic contact was successfully achieved by the deposition of Indium and thermal annealing. The specific contact resistance of about 6.6$\times$$10^{-4}$$\Omega\textrm{cm}^2$ was measured by use of the transmission line method (TLM). However, as the thermal annealing was just performed to ITO/$n^{+}$-InP contact without the deposition of Indium between ITO and $n^{+}$-InP, it exhibited schottky characteristics. In the applications, the DC characteristics of InP/InGaAs HPTs with ITO emitter contacts was compared with that of InP/InGaAs HBTs with the opaque emitter contacts.

• 한국재료학회지
• /
• 제24권3호
• /
• pp.135-139
• /
• 2014

To obtain the transistor with ambipolar transfer characteristics, IGZO/SiOC thin film transistor was prepared on SiOC with various polarities as a gate insulator. The interface between a channel and insulator showed the Ohmic and Schottky contacts in the bias field of -5V ~ +5V. These contact characteristics depended on the polarities of SiOC gate insulators. The transfer characteristics of TFTs were observed the Ohmic contact on SiOC with polarity, but Schottky contact on SiOC with low polarity. The IGZO/SiOC thin film transistor with a Schottky contact in a short range bias electric field exhibited ambipolar transfer characteristics, but that with Ohmic contact in a short range electric field showed unipolar characteristics by the trapping phenomenon due to the trapped ionized defect formation.

• 한국전기전자재료학회:학술대회논문집
• /
• 한국전기전자재료학회 2004년도 하계학술대회 논문집 Vol.5 No.1
• /
• pp.417-420
• /
• 2004

The electrical effects of dry-etch on n-type GaN by an inductively coupled $Cl_2/CH_4/H_2/Ar$ plasma were investigated as a function of ion energy, by means of ohmic and Schottky metallization method. The specific contact resistivity(${\rho}_c$) of ohmic contact was decreased, while the leakage current in Schottky diode was increased with increasing ion energy due to the preferential sputtering of nitrogen. At a higher rf power, an additional effect of damage was found on the etched sample, which was sensitive to the dopant concentration in terms of the ${\rho}_c$ of ohmic contact. This was attributed to the effects such as the formation of deep acceptor as well as the electron-enriched surface layer within the depletion layer. Furthermore, thermal annealing process enhanced the ohmic and Schottky property of heavily damaged surface.

• 한국재료학회지
• /
• 제13권9호
• /
• pp.567-571
• /
• 2003

We investigate vanadium (V)-based Ohmic contacts on n-GaN ($N_{d}$=$2.0${\times}$10^{18}$ $cm^{-3}$ ) as a function of annealing temperature. It is shown that the V (60 nm) contacts become Ohmic with specific contact resistances of $10^{-3}$ $- 10^{-4}$ Ω$\textrm{cm}^2$ upon annealing at 650 and $850^{\circ}C$. The V(20 nm)/Ti(60 nm)/Au(20 nm)contacts produce very low specific contact resistances of $2.2 ${\times}$ 10^{-5}$ and$ 4.0${\times}$10^{-6}$ Ω$\textrm{cm}^2$ when annealed at 650 and $850{\circ}C$, respectively. A comparison shows that the use of the overlayers (Ti/Au) is very effective in improving Ohmic property. Based on the current-voltage measurement, Auger electron spectroscopy, glancing angle X-ray diffraction, and X-ray photoemission spectroscopy results, the possible mechanisms for the annealing temperature dependence of the Ohmic behavior of the V-based contacts are described and discussed.d.

• 한국축산식품학회지
• /
• 제27권4호
• /
• pp.416-423
• /
• 2007

본 실험은 전압의 증가에 따른 염수 침지식 및 전극 접촉식 ohmic 해동 처리가 돈육의 이화학적 특성에 미치는 효과를 규명하고자 실시되었다. 염수 침지식 ohmic 해동방법은 전압에 의한 염수의 온도 상승에 의하여 시료가 해동 됨으로써 시료 표면의 과열 현상이 효과적으로 억제되었고, 해동 후 높은 보수력 및 전단력의 저하가 관찰되었지만, 육색이 다소 저하되는 단점을 나타내었다. 반면 전극 접촉식 ohmic 해동 방법은 해동 과정 중 얼음의 상전이 구간을 빠르게 통과함으로써 빠른 해동이 가능하였고, 해동 후 식육의 품질 저하가 최소화되었지만, 시료의 크기 및 전압의 증가에 따른 심한 표면 과열 현상이 발생할 수 있는 단점을 보였다. 따라서 염수 침지식 해동은 보다 높은 전압을 이용하여 식육을 빠르게 해동하고, 전극 접촉식 해동은 낮은 전압을 이용하여 표면 과열을 억제하면 보다 효과적인 해동이 가능할 것으로 사료되었다.

• 한국전기전자재료학회논문지
• /
• 제14권2호
• /
• pp.123-129
• /
• 2001

The optimal high temperature processing conditions for the formation of Ohmic contact of Ti/Al/Pt/Au multiple layers were established for the fabrication of n$^{+}$-GaN/AlGaN/GaN HFET device. Contact resistivity as low as 3.4x10$^{-6}$ ohm-$\textrm{cm}^2$ was achieved by the annealing of the sample at 100$0^{\circ}C$ for 10 sec. using the RTA (Rapid Thermal Annealing) system. The fabricated HFET (Heterostructure Field Effect Transistor) with a structure of n'-GaN/undoped AlGaN/undoped GaN exhibited a low knee voltage of 3.5 V and a maximum source-drain current density of 180 mA/mm at Vg=0V.V.

• 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.

• 한국진공학회지
• /
• 제11권4호
• /
• pp.201-206
• /
• 2002

N형 InGaAs에 대한 Pd/Si/Pd/Ti/Au 오믹 접촉의 급속 열처리 조건에 따른 오믹 특성을 조사하였다. $450^{\circ}C$까지의 열처리 동안에 전반적으로 우수한 오믹 특성을 나타내어 $400^{\circ}C$, 20초의 급속 열처리 조건에서 최저 $3.9\times10^{-7}\Omega\textrm{cm}^2$ 의 접촉 비저항을 나타내었다. 이는 열처리에 의해 생성된 Pd-Si계 화합물의 형성 및 Si의 InGaAs 표면으로의 확산과 관련이 있었다. 그러나 $400^{\circ}C$에서 열처리 시간을 30초 이상으로 연장할 경우 접촉 비저항이 low-$10^{-6}\Omega \textrm{cm}^2$ 으로 약간 증가하였고, 열처리 조건을 425~$450^{\circ}C$/10초로 변화시킬 경우 high-$10^{-7}$~low-$10^{-6}\Omega \textrm{cm}^2$으로 약간 증가하였다. 이는 오믹 재료와 InGaAs의 반응에 의해 Pd-Ga계 화합물이 형성된 것과 관련이 있었다. 고온 열처리 후에도 오믹 재료와 InGaAs의 평활한 계면을 유지하면서 우수한 오믹 특성을 나타내어, 화합물 반도체 소자의 오믹 접촉으로 충분히 응용 가능하다고 판단된다.