• Journal of the Korean Vacuum Society
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• v.7 no.3
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• pp.169-175
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• 1998

The plasma etching of polysilicon was performed with the HBr/$Cl_2/He-O_2$ gas mixture. The residual layers after photoresist strip were investigated using x-ray photoelectron spectroscopy (XPS) and scanning electron microscopy (SEM). The etch residue was identified as silicon oxide deposited on the top of the patterned polysilicon. In order to clarify the formation mechanism of the etch residue, the effects of various gas mixtures such as $Cl_2/He-O_2$and HBr/$Cl_2$were investigated. We found that the etch residue is well formed in the presence of oxygen, suggesting that the etch residue is caused by the reaction of oxvgen and non-volatile silicon halide compounds. Wet cleaning and dry etch cleaning processes were applied to remove the polysilicon etch residue, which can affect the electrical characteristics and further device processes. XPS results show that the wet cleaning is suitable for the removal of the etch residue.

• Journal of the Korean institute of surface engineering
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• v.41 no.6
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• pp.269-273
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• 2008

The etch of $(Na_{0.5}K_{0.5})NbO_3$ (NKN) thin film was performed in $BCl_3/Cl_2/Ar$ inductively coupled plasma. It was found that the 1sccm addition $BCl_3$ (5%) into $Cl_2/Ar$ plasma caused a non-monotonic behavior of the NKN etch rate. The maximum etch rate of NKN was 95.3 nm/min at $BCl_3$ (1 sccm)/$Cl_2$ (16 sccm)/Ar (4 sccm), 800 W ICP power, 1 Pa pressure and 400 W bias power. The NKN etch rate shows a monotonic behavior a s the bias power increases. The analysis of the narrow scan spectra of XPS for both a s-deposited and etched NKN films allowed one to assume ion assisted etch mechanism. The most probable reason for the maximum etch rate can be defined as a concurrence of chemical and physical etch pathways.

• Transactions on Electrical and Electronic Materials
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• v.8 no.6
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• pp.229-233
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• 2007

In this study, we carried out an investigation of the etching characteristics(etch rate, selectivity) of $HfO_2$ thin films in the $CH_4/Ar$ inductively coupled plasma. It was found that variations of input power and negative dc-bias voltage are investigated by the monotonic changes of the $HfO_2$ etch rate as it generally expected from the corresponding variations of plasma parameters. At the same time, a change in either gas pressure or in gas mixing ratio result in non-monotonic etch rate that reaches a maximum at 2 Pa and for $CH_4(20%)/Ar(80%)$ gas mixture, respectively. The X-ray photoelectron spectroscopy analysis showed an efficient destruction of the oxide bonds by the ion bombardment as well as showed an accumulation of low volatile reaction products on the etched surface. Based on these data, the ion-assisted chemical reaction was proposed as the main etch mechanism for the $CH_4-containing$ plasmas.

• Journal of the Microelectronics and Packaging Society
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• v.8 no.3
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• pp.63-67
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• 2001

Up to now, most studies about Pt-etching have been focused on physical sputtering mechanism with Cl-based plasma, while only a limited results are available for etching characteristics with fluorine-based plasma. In this study, etch characteristics of Pt thin film with $Cl_2$/Ar and $SF_{6}$/Ar Ar gas chemistries have been studied with ECR plasma etching system. It is confirmed that $SF_{6}$/Ar Ar plasma chemistry could make volatile etch-products through the reaction with Pt thin film. Also the improvement in etch rate, etch profile and surface roughness is obtained due to the formation of volatile platinum fluoride compounds.

• Proceedings of the Korean Institute of Navigation and Port Research Conference
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• 2000.11a
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• pp.40-44
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• 2000

In this paper, since the research on the etching of SrBi$_2$Ta$_2$O$_{9}$ (SBT) thin film was few (specially Cl$_2$-base ), we had studied the surface reaction of SBT thin films using the OES in high density plasma etching as a function of rf power, dc bias voltage, and Cl$_2$/(C1$_2$+Ar) gas mixing ratio. It had been found that the etch rate of SBT thin films appeared to be more affected by the physical sputtering between Ar ions and surface of the SBT compared to the chemical reaction in our previous papers$^{1.2}$ . The change of Cl radical density that is measured by the OES as a function of gas combination showed the change of the etch rate of SBT thin films. Therefore, the chemical reactions between Cl radical in plasma and components of the SBT enhance to increase the etch rates of SBT thin films and these results were confirmed by XPS analysis.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2000.11a
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• pp.40-44
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• 2000

In this paper, since the research on the etching of SrBi$_2$Ta$_2$O$_{9}$ (SBT) thin film was few (specially Cl$_2$-base ), we had studied the surface reaction of SBT thin films using the OES in high density plasma etching as a function of rf power, dc bias voltage, and Cl$_2$(Cl$_2$+Ar) gas mixing ratio. It had been found that the etch rate of SBT thin films appeared to be more affected by the physical sputtering between Ar ions and surface of the SBT compared to the chemical reaction in our previous papers$^{1.2}$ . The change of Cl radical density that is measured by the OES as a function of gas combination showed the change of the etch rate of SBT thin films. Therefore, the chemical reactions between Cl radical in plasma and components of the SBT enhance to increase the etch rates of SBT thin films and these results were confirmed by XPS analysis.

• Corrosion Science and Technology
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• v.2 no.4
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• pp.189-193
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• 2003

The Ru etching using $O_2/C_{12}$ plasmas has been studied by employing the helicon etcher. The changes of Ru etch rate, Ru to $SiO_2$ etch selectivity and Ru electrode etching slope with varied process variables were investigated. The Ru etching slope at the optimized etching condition was measured to be $84^{\circ}$. We reveal that the Ru etching using $O_2/C_{12}$ plasma generates the $RuO_2$ thin film. Possible mechanism of Ru etching is discussed.

• Transactions on Electrical and Electronic Materials
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• v.18 no.2
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• pp.74-77
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• 2017

In this work, we investigated the etching characteristics of TaNO thin films and the selectivity of TaNO to $SiO_2$ in an $O_2$/CF4/Ar inductively coupled plasma (ICP) system. The maximum etch rate of TaNO thin film was 297.1 nm/min at a gas mixing ratio of O2/CF4/Ar (6:16:4 sccm). At the same time, the etch rate was measured as a function of the etching parameters, such as the RF power, DC-bias voltage, and process pressure. X-ray photoelectron spectroscopy analysis showed the efficient destruction of the oxide bonds by the ion bombardment, as well as the accumulation of low volatile reaction products on the etched surface. Based on these data, the ion-assisted chemical reaction was proposed as the main etch mechanism for the $CF_4$-containing plasmas.

• 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 Korean Institute of Electrical and Electronic Material Engineers
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• v.16 no.4
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• pp.286-291
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• 2003

(Pb,Sr)TiO$_3$(PST) thin films have attracted great interest as new dielectric materials of capacitors for Gbit dynamic random access memories. In this study, inductively coupled CF$_4$/Ar plasma was used to etch PST thin films. The maximum etch rate of PST thin films was 740 $\AA$/min at a CF$_4$(20 %)/Ar(80 %) 9as mixing ratio, an RF power of 800 W, a DC bias voltage of -200 V, a total gas flow of 20 sccm, and a chamber pressure of 15 mTorr. To clarify the etching mechanism, the residue on the surface of the etched PST thin films was investigated by X-ray photoelectron spectroscopy. It was found that Pb was mainly removed by physically assisted chemical etching. Sputter etching was effective in the etching of Sr than the chemical reaction of F with Sr, while Ti can almost removed by chemical reaction.