• Journal of the Korean Society for Precision Engineering
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• v.19 no.5
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• pp.149-158
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• 2002

Recently, the minimum line width shows a tendency to decrease and the multi-level increases in semiconductor. Therefore, a planarization technique is needed and chemical mechanical polishing(CMP) is considered as one of the most suitable process. CMP accomplishes a high polishing performance and a global planarization of high quality. However there are several defects in CMF, such as micro-scratches, abrasive contaminations and non-uniformity of polished wafer edges. Wet etching process including spin-etching can eliminate the defects of CMP. It uses abrasive-free chemical solution instead of slurry. On this study, ILD(Interlayer-Dielectric) was removed by CMP and wet etching process using DHF(Diluted HF) in order to investigate the possibility of planrization by wet etching mechanism. In the thin film wafer, the results were evaluated from the viewpoint of material removal rate(MRR) and within wafer non-uniformity(WIWNU). And the pattern step heights were also compared for the purpose of planarity characterization of the patterned wafer. Moreover, Chemical polishing process which is the wet etching process with mechanical energy was introduced and evaluated for examining the characteristics of planarization.

• Proceedings of the IEEK Conference
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• 2001.06b
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• pp.237-240
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• 2001

In this paper, we have presented processing technique about wet etching for silicon membrane construction formation. In order to make selective etching of backside silicon wafer, we used Si$_3$N$_4$ layer by PECVD(Plasma Enhanced Chemical Vapor Deposition). We have measured the surface thickness in backside silicon wafer after anisortropic wet etching with KOH:distilled water solutions. Through this experiment, we acquired the etching rate for 1.29${\mu}{\textrm}{m}$/min. The average rough of Si-membrane frontside and backside was 0.26${\mu}{\textrm}{m}$, 0.90${\mu}{\textrm}{m}$, respectively.

• Journal of the Korean Ceramic Society
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• v.42 no.10 s.281
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• pp.645-648
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• 2005

To fabricate a (100) silicon hard master, we used anisotropic wet etching for the embossing. The etching chemical for the sili­con wafer was a TMAH 25$\%$ solution. The anisotropic wet etching produces a smooth sidewall surface inclined at 54.7°, and the surface roughness of the fabricated master is about 1 nm. After spin coating an organic-inorganic sol-gel hybrid resin on a silicon substrate, we used the fabricated master to form patterns on the silicon substrate. Thus, we successfully obtained patterns via the hot embossing technique with the (100) silicon hard master. Moreover, by using a single hydrophobic surface treatment of the master, we succeeded in achieving uniform surface roughness of the embossed patterns for more than ten embossments.

• Korean Chemical Engineering Research
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• v.58 no.3
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• pp.474-479
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• 2020

The etching solution for slimming of glass substrates was manufactured and HF was used as the main ingredient of wet etching solutions. Various types of strong acids such as HCl, HNO₃, H₂SO₄, amino acids and carboxylic acids such as citric acid, and etched solutions, respectively, were used to measure the etching rates and changes in surface shape of the glass. Regardless of the type of strong acids, the etching rate of the glass increased linearly as the added amount increased, and the sludge removal effect of the glass surface was also shown. The etching solution containing HCl showed more efficient results than other strong acids in the etching rate and the effect of removing sludge. The addition of carboxylic acid did not significantly affect the variation of etching rate, but had the effect of removing sludge. However, if amino acids were added, changes in etching rate and sludge removal were not significant.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.26 no.3
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• pp.194-197
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• 2013

We investigated the effect of etching time on the surface roughness, and electrical and optical properties of ZnO and 2 wt% Al-doped ZnO (AZO) films. The ZnO and AZO films were deposited on glass substrates by RF magnetron sputtering technique. The etching experiment was carried out using a solution of 5% HCl at room temperature. The surface roughness was characterized by Atomic Force Microscopy. The electrical property was measured by Hall measurement system and 4-point probe. The optical property was characterized by UV-vis spectroscopy. After the wet chemical etching, the surface textures were obtained on the surface of the ZnO and AZO films. With the increase of etching time, the surface roughness (RMS) of the films increased and the transmittance of the films was observed to decrease. For the AZO film, a low resistivity of $1.0{\times}10^{-3}\;{\Omega}{\cdot}cm$ was achieved even after the etching.

• 한국전기화학회:학술대회논문집
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• 2002.10a
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• pp.49-49
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• 2002

• Journal of the Korean Vacuum Society
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• v.17 no.1
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• pp.73-79
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• 2008

In order to apply for transparent conductive oxide(TCO), we deposited ZnO thin films on the glass at room temperature by RF magnetron sputtering method. Deposition conditions for high transmittance and low resistivity were optimized in our previous studies. Under the deposition condition with the RF power of 200 W, target to substrate distance of 30 mm and working pressure of 5 mTorr, highly conductive($7.4{\times}10^{-3}{\Omega}cm$) and transparent(over 85%) ZnO films were prepared. Highly oriented ZnO film in the [002] direction were obtained with specifically designed ZnO targets. Systematic study on dependence of deposition parameters on electrical and optical properties of the as-grown ZnO films were mainly investigated in this work. And for application tests using these films as transparent conductive oxide anodes, wet chemical etching behaviors of ZnO films were also investigated using various chemicals. Wet-chemical etching behavior of ZnO films were investigated using various acid solutions. The concentrations of these different acid solutions were controlled to study the etching shapes and etching rate. ZnO films were anisotropically etched at various concentrations and wet etching led to crater-like surface structure. Also we firstly found that the etching rate and etching shapes of ZnO films strongly depended on the etchant concentrations (i.e. pH) and the etching rate is exponentially decreased with increasing pH values regardless of the acid etchants.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2010.06a
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• pp.339-339
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• 2010

Photo-assisted wet chemical etching of GaN thin film was studied using KOH based solutions. A $2{\mu}m-2{\mu}m$ titanium line-and-space pattern was used as a etching mask. It is found that the etching characteristics of the GaN thin film is strongly dependent on the pattern direction by unisotropic property of KOH based solution. When the pattern was aligned to the [$11\bar{2}0$] directions, ($10\bar{1}n$)-facet is revealed constructing V-shaped sidewalls.

• Journal of the Korean Society for Precision Engineering
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• v.24 no.5
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• pp.104-109
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• 2007

Photochemical patterning of self-assembled mono layers (SAMs) has been performed by diode pumped solid state (DPSS) 3rd harmonic Nd:$YVO_4$ laser with wavelength of 355 nm. SAMs patternings of parallel lines have subsequently been used either to generate compositional chemical patterns or fabricate microstructures by a wet etching. This paper describes a selective etching process with patterned SAMs of alkanetiolate molecules on the surface of gold. SAMs formed by the adsorption of alkanethiols onto gold substrate employs as very thin photoresists. In this paper, the influence of the interaction between the functional group of SAMs and the etching solution is studied with optimal laser irradiation conditions. The results show that hydrophobic functional groups of SAMs are more effective for selective chemical etching than the hydrophilic ones.

• Proceedings of the Korean Society for Technology of Plasticity Conference
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• 2004.05a
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• pp.245-249
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• 2004

Transparent materials such as fused silica are important materials in optical and optoelectronics field because of its outstanding properties, such as transparency in a wide wavelength range, strong damage resistance for laser irradiation, and high thermal and chemical stability. However, these properties make it difficult to micromachine silica in micro-sized quantities. In this study, we fabricated a micro patterns on the surface of fused silica plate using laser induced wet etching. KrF excimer laser was used as a light source. There were no burrs and micro cracks on the etched surface of fused silica and the flatness of the etched surface was fairly good. We investigated the influence of etchant upon the etch rate and quality in laser induced wet etching. Pyrene-acetone, toluene, and pyrene-toluene solution were used as etchant. In the side of etch rate, toluene and pyrene-toluene solution were better than pyrene-acetone solution.