• Transactions on Electrical and Electronic Materials
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• v.12 no.5
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• pp.209-212
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• 2011

Hafnium nitride (HfN) thin films were deposited onto a silicon substrate by inductive coupled nitrogen plasma-assisted radio frequency magnetron sputtering. The films were prepared without intentional substrate heating and a substrate negative bias voltage ($-V_b$) was varied from -50 to -150 V to accelerate the effects of nitrogen ions ($N^+$) on the substrate. X-ray diffractometer patterns showed that the structure of the films was strongly affected by the negative substrate bias voltage, and thin film crystallization in the HfN (100) plane was observed under deposition conditions of -100 $V_b$ (bias voltage). Atomic force microscopy results showed that surface roughness also varied significantly with substrate bias voltage. Films deposited under conditions of -150 $V_b$ (bias voltage) exhibited higher hardness than other films.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.17 no.7
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• pp.738-746
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• 2004

Recently zinc oxide(ZnO) has emerged as one of the most promising transparent conducting films with a strong demand of low cost and high performance optoelectronic devices, ZnO film has many advantages such as high chemical and mechanical stabilities, and abundance in nature. In this paper, in order to obtain the excellent transparent conducting film with low resistivity and high optical transmittance for Plasma Display Pannel(PDP), aluminium doped zinc oxide films were deposited on Corning glass substrate by dc magnetron sputtering method. The effects of the discharge power and doping amounts of $Al_2$$O_3$ on the electrical and optical properties were investigated experimentally. Particularly in order to lower the electrical resistivity, positive and negative bias voltages were applied on the substrate, and the effect of bias voltage on the electrical properties of ZnO:Al thin film were also studied and discussed. Films with lowest resistivity of $4.3 \times 10 ^{-4} \Omega-cm$ and good transmittance of 91.46 % have been achieved for the films deposited at 1 mtorr, $400^{\circ}C$, 40 W, Al content of 2 wt% with a substrate bias of +30 V for about 800 nm in film thickness.

• Journal of the Microelectronics and Packaging Society
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• v.12 no.3 s.36
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• pp.207-212
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• 2005

Al, Ti, Ta, and Cr thin films were deposited on a polyimide substrate using DC magnetron sputter to study the adhesion characteristics of metal films on polyimide substrates, while RF bias of 0 - 400 W was applied to the substrate during DC sputtering. The adhesion strength was evaluated using a 90-degree peel test. The peel tests showed that the adhesion strength was enhanced by applying the RF bias to the substrate in all specimens. Scanning electron microscopy and Auger depth profile of the fractured surfaces indicate that the polyimide underwent cohesive failure during peeling and heavy deformation was also observed in the metal films peeled from the polyimide substrate when the RF bias applied during the deposition. Cross-sectional transmission electron microscopy revealed that the metal/polyimide interface was not clear and complicated. This complicated interface, likely formed due to the RF bias applied to the substrate, was attributed to the adhesion enhancement observed during the bias sputtering.

• Transactions on Electrical and Electronic Materials
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• v.5 no.4
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• pp.153-157
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• 2004

ITO thin films were deposited on PET and soda-lime glass substrates by a dc reactive magnetron sputtering of In-Sn alloy metal target without substrate heater and post-deposition thermal treatment. The dependency of rf-bias voltage and substrate power during deposition processing was investigated to control the electrical and optical properties of ITO films. The range of rf bias voltage is from 0 to -80 V and the substrate power is applied from 10 to 50 W. The minimum resistivity of ITO film is 5.4${\times}$10$^{-4}$ $\Omega$cm at 50 W power and rf-bias voltage of -20 V. The best transmittance of ITO films at 550 nm wavelength is 91 % in the substrate power of 30 W and rf-bias voltage of -80 V.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.20 no.8
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• pp.706-710
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• 2007

Ti-containing amorphous carbon (a-C:Ti) films shows attractive mechanical properties such as low friction coefficient, good adhesion to various substrate and high wear resistance. The incorporation of titanium in a-C films is able to improve the electrical conductivity, friction coefficient and adhesion to various substrates. In this study, a-C:Ti films were depositied on Si wafer by closed-field unbalanced magnetron (CFUBM) sputtering system composed two targets of carbon and titanium. The tribological properties of a-C:Ti films were investigated with the increase of DC bias voltage from 0 V to - 200 V. The hardness and elastic modulus of films increase with the increase of DC bias voltage and the maximum hardness shows 21 GPa. Also, the coefficient of friction exhibites as low as 0.07 in the ambient. In the result, the a-C:Ti film obtained by CFUBM sputtering method improved the tribological properties with the increase of DC bias volatage.

• Journal of the Korean institute of surface engineering
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• v.36 no.2
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• pp.148-154
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• 2003

Short ($\tau$=40 $mutextrm{s}$) and high-voltage ($U_{sub}$=2~8 kV) negative substrate bias pulses were used to assist pulsed magnetron sputtering DLC films deposition. Space- and time-resolved probe measurements of the plasma characteristics have been performed. It was shown that in case of high-voltage substrate bias spatial non-uniformity of the magnetron discharge plasma density greatly affected DLC deposition process. By Raman spectroscopy it was found that maximum percentage of s $p^3$-bonded carbon atoms (40 ~ 50%) in the coating was attained at energy $E_{c}$ ~700 eV per deposited carbon atom. Despite rather low diamond-like phase content these coatings are characterized by good adhesion due to ion mixing promoted by high acceleration voltage. Short duration of the bias pulses is also important to prevent electric breakdowns of insulating DLC film during its growth.wth.

• Journal of the Korean Electrochemical Society
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• v.6 no.4
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• pp.261-265
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• 2003

The heat treatment process of thin film microbatteries manufacturing processes has several Problems. This study, without heat treatment, considered the characteristics of $LiCoO_2$ thin films deposited by bais sputtering method inducing the structural change of the thin film. The properties of deposited $LiCoO_2$ thin films such as crystal structure, morphology, and discharge capacity were observed by various analysis methods. Among $LiCoO_2$ thin films deposited by substrate bias $voltage(V_b)$, the one deposited by substrate bias voltage of -50V had the highest initial discharge capacity of about $60{\mu}Ah/cm^2{\mu}m.$ We confirmed that $LiCoO_2$ thin film could be used as cathode material of lithium thin film microbatteries without annealing.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.17 no.3
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• pp.278-282
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• 2004

The Hydrogenated amorphous carbon(a-C:H) thin films are deposited on silicon with a close field unbalanced magnetron(CFUBM) sputtering systems. The experimental data are obtained on the depositon rate and physical properties of a-C:H films using DC bias voltage and Ar/C$_2$H$_2$ pressure. The depostion rate and the surface roughness decrease with DC bias voltage, but the hardness of the thin films increases with DC bias voltage. And the position of G-peak moves to lower wavenumber indicating an increase in diamond-like carbon characteristics with the lower Ar/C$_2$H$_2$ pressure.

• Journal of the Korean institute of surface engineering
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• v.41 no.6
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• pp.287-291
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• 2008

Reactively magnetron sputtered TiN films were deposited on Si wafers under varying bias voltage and characterized by X-ray diffraction, field-emission scanning electron microscopy and Nanoindentation. The films deposited under an Ar + $N_2$ atmosphere exhibited a mixed (200)-(111) orientation with a strong (200) texture, which subsequently changed to a strong (111) texture with increasing bias voltage. The changes in texture and grain size of the TiN thin films are due to one or a combination of factors such as strain energy, surface free energy, surface diffusivity and adatom mobility. The influence of each factor depends on the processing conditions. The average deposition rate and grain size were calculated from FE-SEM images of the films indicating that the deposition rate was lower at the films deposited under bias voltage.

• Journal of the Korean institute of surface engineering
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• v.29 no.3
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• pp.149-156
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• 1996

Conducting diamond-like carbon films are synthesized using Triode Magnetron Sputtering-Plasma Enhanced Chemical Vapor Deposition(TMS-PECVD), and are examined by four point probe, microhardeness tester, and scanning electron miscroscopy(SEM). As the target bias and Ar/CH$_4$, ratio increase, the electrical resitivity and microhardness of the films are found to decrease, and also, their surface morphologies tend to be rough. While the resistivities of the films are shown to increase in proportion to the increase of the substrate bias, the microhardness of the films is shown to be maximun value(1600kg/$\textrm{mm}^2$) at a certain substrate bias(-70V). We can obtain the conducting diamond-like carbon films with the microhardness of 1600(kg/$\textrm{mm}^2$) and electrical resitivity of 16($\Omega$cm) at the process condition such as target bias -400V, substrate bias -70V, and Ar/$CH_4$ ratio 20.