• Transactions on Electrical and Electronic Materials
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• v.11 no.3
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• pp.116-119
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• 2010

The etching characteristics of zinc oxide (ZnO) were investigated, including the etch rate and the selectivity of ZnO in a $Cl_2/BCl_3$/Ar plasma. It was found that the ZnO etch rate, the RF power, and the gas pressure showed non-monotonic behaviors with an increasing Cl2 fraction in the $Cl_2/BCl_3$/Ar plasma, a gas mixture of $Cl_2$(3 sccm)/$BCl_3$(16 sccm)/Ar (4 sccm) resulted in a maximum ZnO etch rate of 53 nm/min and a maximum etch selectivity of 0.89 for ZnO/$SiO_2$. We used atomic force microscopy to determine the roughness of the surface. Based on these data, the ion-assisted chemical reaction was proposed as the main etch mechanism for the plasmas. Due to the relatively low volatility of the by-products formed during etching with $Cl_2/BCl_3$/Ar plasma, ion bombardment and physical sputtering were required to obtain the high ZnO etch rate. The chemical states of the etched surfaces were investigated using X-ray photoelectron spectroscopy (XPS). This data suggested that the ZnO etch mechanism was due to ion enhanced chemical etching.

• 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.

• The Transactions of the Korean Institute of Electrical Engineers C
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• v.49 no.5
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• pp.265-269
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• 2000

$(Ba, Sr)TiO_3$thin films were etched with a magnetically enhanced inductively coupled plasma (MEICP) at different CF4/Ar gas mixing ratios. Experimental was done by varying the etching parameters such as rf power, dc bias and chamber pressure. The maximum etch rate of the BST films was $1800{AA}/min$ under $CF_4/(CF_4+Ar)$ of 0.1, 600 W/350 V and 5 mTorr. The selectivity of BST to Pt and PR was 0.6, 0.7, respectively. X-ray photoelectron spectroscopy (XPS) results show that surface reaction between Ba, Sr, Ti and C, F radicals occurs during the (Ba, Sr)TiO3 etching. To analyze the composition of surface residue after the etching, films etched with different CF_4/Ar$ gas mixing ratio were investigated using XPS and secondary ion mass spectroscopy (SIMS).

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2000.04b
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• pp.52-55
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• 2000

In this study, (Ba,Sr)$TiO_3$(BST) thin films were etched with a magnetically enhanced inductively coupled plasma(MEICP) as a function Ar/$CF_4$ gas mixing ratio. Experiment was done by varying the etching parameters such as rf power, dc bias voltage and chamber pressure. The maximum etch rate of the BST films was 1700 ${\AA}/min$ under $CF_4/(CF_4+Ar)$ of 0.1, 600 W/350 V and 5 mTorr. The selectivity of BST to Pt and PR was 0.6, 0.7, respectively. X -ray photoelectron spectroscopy(XPS) studies shows that there are surface reaction between Ba, Sr, Ti and C, F radicals during the etching. To analyze the composition of surface residue remaining after the etching, films etched with different $CF_4$/Ar gas mixing ratio were investigated using XPS.

• Proceedings of the KIEE Conference
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• 1997.11a
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• pp.276-278
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• 1997

The reliable etching process is one of the essential steps in fabricating GaN based-device. High etch rate is needed to obtain a deeply etched structure and perfect anisotropic etched facet is needed to obtain lasing profile. In the research, therefore, we had proposed a planar inductively coupled plasma etcher (Planar ICP Etcher) as a high density plasma source, and studied the etching mechanism using the $CH_4/H_2$/Ar gas mixture. Dry etching characteristics such as etch rate, anisotropic etching profile and so on, for the III-V nitride layers were investigated using Planar ICP Etcher, based on the plasma characteristic as a variation of plasma process parameters.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2005.11a
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• pp.124-125
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• 2005

ZnS:Mn thin films have attracted great interest as electroluminescence devices. In this study, inductively coupled BCl$_3$/Ar plasma was used to etch ZnS:Mn thin films. We obtained the maximum etch rate of ZnS:Mn thin films was 2209 ${\AA}$/min at a BCl$_3$(20%)/Ar(80%) gas mixing ratio, an RF power of 700 W, a DC bias voltage of-250 V, a total gas flow of 20 sccm, and a chamber pressure of 1 Pa. It was proposed that sputter etching is dominant etching mechanism while the contribution of chemical reaction is relatively low due to low volatility of etching products.

• 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.

• Proceedings of the KIEE Conference
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• 2004.11a
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• pp.98-100
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• 2004

In this study, PST thin films were etched with inductively coupled $Cl_2/(Cl_2+Ar)$ plasmas. The etch characteristics of PST thin films as a function of $Cl_2/(Cl_2+Ar)$ gasmixtures were analyzed by using quadrupole mass spectrometer (QMS). Systematic studies were carried out as a function of the etching parameters, including the RF power and the working pressure. The maximum PST film etch rate is 56.2 nm/min, because a small addition of $Cl_2$ to the $Cl_2$/Ar mixture increased the chemical effect. It was proposed that sputter etching is the dominant etching mechanism while the contribution of chemical reaction is relatively low due to low volatility of etching products.

• Journal of the Korean institute of surface engineering
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• v.32 no.3
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• pp.416-422
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• 1999

The characteristics of inductively coupled Cl$_2$/BCl$_3$ plasmas during the GaN etching were studied using plasma mass spectrometry by measuring the relative amounts of reactive ions, neutrals, and etch products. GaN etch rates increased with the increase of pressure and showed a maximum near 25mTorr for the pure $Cl_2$ and near 30mTorr for $Cl_2$$BCl_3$. The addition of$ BCl_3$ to $Cl_2$ also was increased GaN etch rates until 50%BCl$_3$ was mixed to $Cl_2$. The GaN etching with pure $Cl Cl_2$ appears to be related to the combination of Cl$_2^{+}$ ion bombardment and the chemical reaction of Cl radicals. In the case of the GaN etching with Cl$_2$/BCl$_3$, in addition to the combined effect of$_2^{ +}$ ions and Cl radicals, $_BCl2^{+ }$ ions appear to be responsible for some of GaN etching even though they do not have significant effect on the GaN etching compared to $Cl_2^{+}$ and Cl. $Ga^{+ }$ , $GaCl^{+}$ , $GaCl_2^{+}$ , and $N_2^{+}$ were observed as the positive ions of etch products, and the intensities of these etch products showed the same trends as those of GaN etch rate. Among the etch products, Ga and $N_2$ appear to be the main etch products.

• Journal of the Institute of Electronics Engineers of Korea SD
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• v.39 no.8
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• pp.12-16
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• 2002

It is confirmed that the ITO(Indium Tin Oxide) thin films can be etched by low-temperature plasma at atmospheric pressure. The etching happened deepest at a hydrogen flow rate of 4 sccm, and the etch rate was 120 /min. The etching speed corresponded to the H$\alpha$* emission intensity The etching mechanism of the ITO thin films is as follows; thin films were reduced by H$\alpha$*, and the metal compound residues were detached from the substrate by reacting on the CH* The etching was started after etching time of initial 50 sec and above the threshold temperature of 145$^{\circ}C$. The activation energy of 0.16 eV(3.75 Kcal/mole) was obtained from the Arrehenius plots.