• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.24 no.6
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• pp.445-448
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• 2011

In this study, the etching characteristics of $Al_2O_3$ thin films were investigated using an ICP (inductively coupled plasma) of $BCl_3$/Ar gas mixture. The etch rate of $Al_2O_3$ thin films as well as the $SiO_2/Al_2O_3$ etch selectivity were measured as functions of $BCl_3$/Ar mixing ratio (0~100% Ar) at a constant gas pressure (10 mTorr), total gas flow rate (40 sccm), input power (800 W) and bias power (100 W). The behavior of the $Al_2O_3$ etch rate was shown to be quite typical for ion-assisted etch processes with a dominant chemical etch pathway. To analyze the etching mechanism using DLP (double langmuir probe), OES (optical emission spectroscopy) and surface analysis using XPS (x-ray photoelectron spectroscopy) were carried out.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.24 no.4
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• pp.276-279
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• 2011

This work, the etching characteristics of $Ba_2Ti_9O_{20}$(BTO) thin films were investigated using an inductively coupled plasma (ICP) of $Ar/Cl_2$ gas mixture. The etch rate of BTO thin films as well as the $BTO/SiO_2$ and BTO/PR etch selectivity were measured as functions of $Ar/Cl_2$ mixing ratio (0~100% Ar) at a constants gas pressure (6 mTorr), total gas flow rate (50 sccm), input power (700 W) and bias power (200 W). The etch rate of BTO thin films decreased with increasing Ar fraction. To analyze the etching mechanism an optical emission spectroscopy (OES), double Langmuir probe(DLP) and surface analysis using X-ray photoelectron spectroscopy (XPS) were carried out.

• Journal of the Microelectronics and Packaging Society
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• v.14 no.3
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• pp.15-20
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• 2007

Low temperature processed ZnO-TFTs on glass below $270^{\circ}C$ for plastic substrate applications were fabricated and their electrical properties were investigated. Films in ZnO-TFTs with bottom gate configuration were made by RF magnetron sputtering system except for $SiO_2$ gate oxide deposited by ICP-CVD. ZnO channel films were grown on glass with various Ar and $O_2$ flow ratios. All of the fabricated ZnO-TFTs showed perfectly the enhancement mode operation, a high optical transmittance of above 80% in visible ranges of the spectrum. In the ZnO-TFTs with pure Ar process, the field effect mobility, threshold voltage, and on/off ratio were measured to be $1.2\;cm^2/Vs$, 8.5 V, and $5{\times}10^5$, respectively. These characteristic values are much higher than those of the ZnO-TFTs of which ZnO channel layers were processed with additional $O_2$ gas. In addition, ZnO-TFT with pure Af process showed smaller swing voltage of 1.86v/decade compared to those with $Ar+O_2$ process.

• Transactions on Electrical and Electronic Materials
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• v.9 no.1
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• pp.12-15
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• 2008

Hafnium oxynitride films have been deposited onto a silicon substrate by means of radio frequency (RF) reactive sputtering using a hafnium dioxide $(HfO_2)$ target with a variety of nitrogen! argon $(N_2/Ar)$ gas flow ratios. Auger electron spectroscopy (AES)results confirm that $N_2$ was successfully incorporated into the HfON films. An increase in the $N_2/Ar$ gas flow ratio resulted in metal oxynitride formation. The films prepared with a $N_2/Ar$ flow ratio of 20/20 sccm show (222), (530), and (611) directions of $HfO_2N_2$, and the (-111), (311) directions of $HfO_2$. From X-ray reflectometry measurements, it can be concluded that with $N_2$ incorporated into the HfON films, the film density increases. The density increases from 9.8 to $10.1g/cm^3$. XRR also reveals that the surface roughness is related to the $N_2/Ar$ flow ratio.

• Journal of the Korean Ceramic Society
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• v.41 no.2
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• pp.106-110
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• 2004

Nickel oxide (NiO) thin films were prepared on Si(100) substrates at room temperature by RF magnetron sputtering using a NiO target. The effects of oxygen flow ratio for the plasma gas on the preferred orientation and surface morphology of the NiO films were investigated. Highly crystalline NiO film with (100) orientation was obtained when it was deposited in pure Ar gas. For NiO film deposited in pure O$_2$ gas, on the other hand, the orientation of the film changed from (100) to (111) and its deposition rate decreased. The origin of the preferred orientation of the films was discussed. NiO films also showed different surface morphologies and roughnesses with the oxygen flow ratio.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2010.06a
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• pp.384-384
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• 2010

The surface reaction characteristics of Zinc Oxide (ZnO) in $Cl_2/BCl_3$/Ar gas ratio using inductively coupled plasma system were investigated. It was found that ZnO etch rate shows a non-monotonic behavior with increasing both Ar fraction in $Cl_2/BCl_3$ plasma, RF power, and gas pressure. The maximum ZnO etch rate of 53 nm/min was obtained for $Cl_2$(3 sccm)/$BCl_3$(16 sccm) /Ar(4 sccm) gas mixture. The chemical state of etched surfaces was investigated with X-ray diffraction (XRD) and the etched surface was investigated to the rms by atomic force microscopy (AFM). From these data, the suggestions on the ZnO etch mechanism were made by secondary ion mass spectrometery (SIMS).

• Journal of the Semiconductor & Display Technology
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• v.9 no.1
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• pp.35-40
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• 2010

We have investigated the effects of hydrogen injection via in-situ gas addition ($O_2$, $H_2$, or $O_2$ + $H_2$ gas) and plasma post-treatment (Ar or Ar + H plasma) on material properties of ZnO that is considered to be as a channel layer in transparent thin film transistors. The variations in the electrical resistivity, optical transmittance and bandgap energy, and crystal quality of ZnO thin films were characterized in terms of the methods and conditions used in hydrogen injection. The resistivity was significantly decreased by injection of hydrogen; approximately $10^6\;{\Omega}cm$ for as-grown, $1.2\;{\times}\;10^2\;{\Omega}cm$ for in-situ with $O_2/H_2\;=\;2/3$ addition, and $0.1\;{\Omega}cm$ after Ar + H plasma treatment of 90 min. The average transmittance of ZnO films measured at a wavelength of 400-700 nm was gradually increased by increasing the post-treatment time in Ar + H plasma. The optical bandgap energy of ZnO films was almost monotonically increased by decreasing the $O_2/H_2$ ratio in in-situ gas addition or by increasing the post-treatment time in Ar + H plasma, while the post-treatment using Ar plasma hardly affected the bandgap energy. The role of hydrogen in ZnO was discussed by considering the creation and annihilation of oxygen vacancies as well as the formation of shallow donors by hydrogen.

• Journal of the Korean Ceramic Society
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• v.32 no.9
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• pp.1085-1091
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• 1995

Molybdenum disilicide (MoSi2) was synthesized from Mo, MoO3, Si and Al powders by self-propagating high temperature synthesis (SHS). The effect of processing parameters such as Mo/MoO3 molar ratio, Ar gas pressure in the reactor and pressing pressure of compacts in synthesis of MoSi2 were investigated. h-MoSi2 was transformed into t-MoSi2 with increasing the Mo/MoO3 mole ratio, and only t-MoSi2 phase was identified above 3.5 : 1 (molar ratio). The synthesized phases did not change with the variation of Ar gas pressure and pressing pressure of compacts. It was found that the combustion temperature was above 2,50$0^{\circ}C$. The products were separated into MoSi2 (s) and $\alpha$-Al2O3 by the difference of their specific grativities. Bending strength, hardness and density of sintered specimen exhibited 82 MPa, 5.368 GPa and 5.43 g/㎤, respectively.

• Proceedings of the Korean Institute of Navigation and Port Research Conference
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• 2000.11a
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• pp.25.1-28
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• 2000

In this study, $Y_2O_3$ thin films were etched with inductively coupled plasma (ICP). The etch rate of $Y_2O_3$ , and the selectivity of $Y_2O_3$ to YMnO$_3$were investigated by varying $Cl_2$/($Cl_2$+Ar) gas mixing ratio. The maximum etch rate of $Y_2O_3$ , and the selectivity of $Y_2O_3$ to YMnO$_3$ were 302/min, and 2.4 at $Cl_2$/($Cl_2$+Ar) gas mixing ratio of 0.2 repetitively. In x-ray photoelectron spectroscopy (XPS) analysis, $Y_2O_3$ thin film was dominantly etched by Ar ion bombardment, and was assisted by chemical reaction of Cl radical. These results were confirmed by secondary ion mass spectroscopy(SIMS) analysis. YCl, and $YC_3$ existed at 126.03 a.m.u, and 192.3 a.m.u, respectively.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2000.11a
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• pp.25-28
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• 2000

In this study, $Y_2$O$_3$ thin films were etched with inductively coupled plasma (ICP). The etch rate of $Y_2$O$_3$, and the selectivity of $Y_2$O$_3$ to YMnO$_3$ were investigated by varying Cl$_2$/(Cl$_2$+Ar) gas mixing ratio. The maximum etch rate of $Y_2$O$_3$, and the selectivity Of $Y_2$O$_3$ to YMnO$_3$ were 302/min, and 2.4 at Cl$_2$/(Cl$_2$+Ar) gas mixing ratio of 0.2 repectively. In x-ray photoelectron spectroscopy (XPS) analysis, $Y_2$O$_3$ thin film was dominantly etched by Ar ion bombardment, and was assisted by chemical reaction of Cl radical. These results were confirmed by secondary ion mass spectroscopy(SIMS) analysis. YCI, and YCl$_3$ existed at 126.03 a.m.u, and 192.3 a.m.u, respectively