• Proceedings of the KIEE Conference
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• 2000.07c
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• pp.1640-1642
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• 2000

We were fabricated of NiCr thin film resitors(TFR) on $Al_{2}O_3$ substrates by dc magnetic sputtering, system. The characteristics of electrical resistance by substrates & annealing condition on the resistors were studied by X-ray Diff. and SEM, ESCA.

• Proceedings of the KIEE Conference
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• 2000.07c
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• pp.1637-1639
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• 2000

Resister networks are used widely in many, high frequency applications for attenuators. In this paper we studied the frequency characteristics of attenuator using network analyzer and compared Ni-Cr thin film resistor with thick film resistor attenuator. Also from return loss, insertion loss and VSWR we obtained the maximum available frequency of these attenuators.

• Journal of the Korean Magnetics Society
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• v.12 no.3
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• pp.94-98
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• 2002

Sputtering conditions and various underlayer such as Al, Cu, Ni, Cr, Ag, Mg, Fe, Co, Pd, Au, Pt, Mo and Hf were investigated for coercivity enhancement of 20 nm Ti/CoCrPt thin films in order to increase the coercivity of the films thinner than 20 nm. Among them, Ag and Mg were effective to increase the coercivity. Particularly 2 nm Ag was very effective to increase the coercivity and nucleation field as well as to reduce ${\alpha}$ value in CoCrPt thin film such that the coercivity of 2 nm Ag/18 nm Ti/10 nm CoCrPt film was 2200 Oe. However, it seemed that other coercivity enhancement mechanism operated in CoCrPt films because Ti (002) preferred texture was not developed with Ag underlayer contrary to a general expectation. And the coercivity and nucleation field were decreased when glass substrate with rougher surface was used.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2001.07a
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• pp.809-812
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• 2001

We were fabricated of NiCr thin film resistors on A1$_2$O$_3$and SiO$_2$/Si substrates by dc magnetron sputtering system. The AC characteristics of resistors were studied. The cut-off frequency were found >10 MHz for the resistors with 39 ohm value of Alumina substrates, but the cut-off frequency were found 400 kHz for the resistors with 168 ohm value of SiO$_2$/Si substrates. In high frequency applications, the substrate selection is the most important factor.

• Journal of the Korean Magnetics Society
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• v.9 no.4
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• pp.210-216
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• 1999

The objective of this paper is to investigate corrosion behaviors of CoCrTa/CrNi thin film and post heat-treatment effect. An electron beam evaporator was used for films deposition. After evaporation, post heat-treatment was carried out under $5.0{\times}10^3$ Torr vacuum condition. Annealing temperature and time were 400 $^{\circ}C$ and 30 min, respectively. To understand the effect of annealing on corrosion behavior of CoCrTa/CrNi, potentiodynamic polarization technique and accelerated corrosion chamber test were undertaken. Corrosion potential is higher for the annealed samples (CoCrTa 400$\AA$/CrNi 1000$\AA$) than for as-deposited one. This is attributed to an enrichment of Cr in the surface layer of the thinfilm resulting in a more corrosion resistant material.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2006.06a
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• pp.337-338
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• 2006

The 200 nm thick-NiCr films grew on $SiO_2$/Si substrates at various deposition temperatures by a dc magnetron co-sputtering technique were characterized for the variation of film texture. The resistivity of the films decreases with increasing deposition temperature and temperature coefficient of electrical resistance (TCR) varies from negative value to a positive one with increasing deposition temperature. The NiCr films deposited at $300^{\circ}C$ exhibit 4 ppm/K being near zero TCR, resulting in TCR suitable for $\pi$-type attenuator applications.

• Proceedings of the International Microelectronics And Packaging Society Conference
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• 2003.11a
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• pp.84-87
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• 2003

Since Pb-free solder alloys have been used extensively in microelectronic packaging industry, the interaction between UBM (Under Bump Metallurgy) and solder is a critical issue because IMC (Intermetallic Compound) at the interface is critical for the adhesion of mechanical and the electrical contact for flip chip bonding. IMC growth must be fast during the reflow process to form stable IMC. Too fast IMC growth, however, is undesirable because it causes the dewetting of UBM and the unstable mechanical stability of thick IMC. UP to now. Ni and Cu are the most popular UBMs because electroplating is lower cost process than thin film deposition in vacuum for Al/Ni(V)/Cu or phased Cr-Cu. The consumption rate and the growth rate of IMC on Ni are lower than those of Cu. In contrast, the wetting of solder bumps on Cu is better than Ni. In addition, the residual stress of Cu is lower than that of Ni. Therefore, the alloy of Cu and Ni could be used as optimum UBM with both advantages of Ni and Cu. In this paper, the interfacial reactions of Sn-3.5Ag-0.7Cu solder on Ni-xCu alloy UBMs were investigated. The UBMs of Ni-Cu alloy were made on Si wafer. Thin Cr film and Cu film were used as adhesion layer and electroplating seed layer, respectively. And then, the solderable layer, Ni-Cu alloy, was deposited on the seed layer by electroplating. The UBM consumption rate and intermetallic growth on Ni-Cu alloy were studied as a function of time and Cu contents. And the IMCs between solder and UBM were analyzed with SEM, EDS, and TEM.

• Electrical & Electronic Materials
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• v.8 no.4
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• pp.464-471
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• 1995

메그네트론 스퍼터링으로 제작한 고밀도 다층박막($Co_75{{Pt_12}{Cr_13}}$합금) 디스크를 투과전자현미경을 이용해 단면 및 평면의 미세조직의 조사 혹은 미소부위 성분분석을 할 경우, 선행되어야하는 시편준비 경로와 각 단계별 구체적방법 및 그 효과를 연구하였다. Ion밀링시간이 증가함에 따라 시료가 얇게 되는과정에서 스퍼터링된 물질이 관찰될 시편부위의 다른 표면에 증착되므로써 미세조직의 선명도를 해칠 수 있고, 이로인한 해석상의 오류가능성이 시사되었다. 또한, 자기박막 디스크와 같이 다층으로 구성된 단면분석용 시료에서는 서로 맞붙인 실리콘 단결정 접착면을 따라 밀링속도가 선택적으로 커서 우선축이 생김으로써 양질의 시편을 얻기 어려운 문제점이 제기되었다. 이같은 문제를 포함한 전자현미경 시료준비과정에서 생길 수 있는 문제를 해결할 수 있는 실마리와 이를 이용해 수행한 전자현미경 분석결과 및 효과적인 시편준비방법이 본 논문에서 언급되었다.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.23 no.10
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• pp.763-766
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• 2010

By improving the conducting process of metal source/drain (S/D) in direct contact with the channel, schottky barrier metal-oxide-semiconductor field effect transistors (SB MOSFETs) reveal low extrinsic parasitic resistances, offer easy processing and allow for well-defined device geometries down to the smallest dimensions. In this work, we investigated the arrhenius plots of the SB MOSFETs with different S/D schottky barrier (SB) heights between simulated and experimental current-voltage characteristics. We fabricated SB MOSFETs using difference S/D metals such as Cr (${\Phi}_{Cr}$ ~4.5 eV) and Ni (${\Phi}_{Ni}$~5.2 eV), respectively. Schottky barrier height (${\Phi}_B$) of the fabricated devices were measured to be 0.25~0.31 eV (Cr-S/D device) and 0.16~0.18 eV (Ni-S/D device), respectively in the temperature range of 300 K and 475 K. The experimental results have been compared with 2-dimensional simulations, which allowed bandgap diagram analysis.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.20 no.4
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• pp.352-356
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• 2007

The Ni/Cr/Al/Cu (51/41/4/4 wt%) thin films were deposited by using DC magnetron sputtering method for the application of the resistors having low TCR (temperature coefficients of resistance) and high resistivity from the former printed-results[3]. The TCR values measured on the as-deposited thin film resistors were less than ${\pm}10\;ppm/^{\circ}C$ and $-6{\sim}+1\;ppm/^{\circ}C$ after annealing and packaging process. The TCR values were $-3{\sim}1\;ppm/^{\circ}C$ (ratio of variation : about 0.02 %) and $-30{\sim}20\;ppm/^{\circ}C$ (ratio of variation : about $0.5{\sim}1\;%$) for the thermal cycling and PCT (pressure cooker test), respectively. It was confirmed that the reliability properties of the thin film resistor were good for electronic components.