• Journal of the Korean Vacuum Society
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• v.1 no.1
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• pp.145-152
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• 1992

Si surfaces exposed to CHF3/C2F6 gas plasmas ih reactive ion etching (RIE) have been characterized by X-ray photoelectron spectroscopy (XPS). CHF3/C2F6 gas plasma exposure of Si surface leads to the deposition of residual film containing carbon and fluorine. The narrow scan spectra of C 1s show various bonding states of carbon as C-Si, C-F/H, C-CFx(x $\leq$ 3), C-F, C-F2, and C-F3. The chemical bonding states of fluorine are described with F-Si, F-C and F-O. And the oxygen and silicon are also detected. The effects of parameters for reactive ion etching as CHF3/C2F6 gas ratio, RF power, and pressure are investigated.

• The Transactions of the Korean Institute of Electrical Engineers
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• v.41 no.5
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• pp.492-501
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• 1992

In this paper, an ion analyzer is used in conjunction with a Langmuir probe to study the chracteristics of ECR plasma such as the ion temperature, ion current density and electron temperature as the operating pressure, ${\mu}$-wave power and axial position change, Silicon etching has been performed with RF-biasing and its etching chracteristics have been discussed in terms of the ion energy distribution function. The maximum value of ion current density appears in the range of 10S0-3T mbar and the broadening of ion energy distribution function increases as pressure increases. Therefore, as pressure decreases, anisotropy increases but selectivity to photoresist decreases.

• Journal of the Semiconductor & Display Technology
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• v.21 no.2
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• pp.45-50
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• 2022

The etching with high selectivity of silicon dioxide over silicon nitride is essential in semiconductor fabrication, and gas phase etch (GPE) can increase the competitiveness of the selective dielectric etch. In this work, GPE of plasma enhanced chemical vapor deposited SiO₂ was performed, and the effects of process parameters, such as temperature, partial pressure ratio, and gas supply cycle, are investigated in terms of etch rate and within wafer uniformity. Employing multiple regression analysis, the importance of each parameter elements is analyzed.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2000.04b
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• pp.10-13
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• 2000

The notching effect in etching of un doped amorphous silicon gate had different characteristics and mechanism comparing with reported ones. The undoped amorphous silicon was etched by using HBr gas plasma, First, in the region of small line width, the potential was increased as a result of ions in the exposed surface of oxide, and the incident ions between the small line width were deflected more wide range, therefore the depth of notching was shallow and wide, Second, in the region of large line width of gate, electrons were charged on the top of photoresist and the side of gate, a part of ions deflected, The deflected ions were locally charged positive on the side of gate, and then the potential difference was produced, therefore, ions stored up more at independent line than at dense line, and nothing became deeper by Br ion bombardment.

• Electrical & Electronic Materials
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• v.8 no.1
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• pp.90-94
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• 1995

Reactive Ion Etching(RIE) of Si$_{3}$N$_{4}$ in a CF$_{4}$/O$_{2}$ gas plasma exhibits such good anisotropic etching properties that it is widely employed in current VLSI technology. However, the RIE process can cause serious damage to the silicon surface under the Si$_{3}$N$_{4}$ layer. When an atmospheric pressure chemical vapor deposited(APCVD) SiO$_{2}$ layer is used as a etch-stop material for Si$_{3}$N$_{4}$, it seems inevitable to get a good etch selectivity of Si$_{3}$N$_{4}$ with respect to SiO$_{2}$. Therefore, we have undertaken thorough study of the dependence of the etch rate of Si$_{3}$N$_{4}$ plasmas on $O_{2}$ dilution, RF power, and chamber pressure. The etch selectivity of Si$_{3}$N$_{4}$ with respect to SiO$_{2}$ has been obtained its value of 2.13 at the RF power of 150 W and the pressure of 110 mTorr in CF$_{4}$ gas plasma diluted with 25% $O_{2}$ by flow rate.

• Journal of Sensor Science and Technology
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• v.6 no.6
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• pp.430-436
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• 1997

A piezoresistive acceleration sensor for 30 G has been fabricated by silicon micromachining method using SDB(silicon direct bonding) wafer. The structure of the piezoresistive acceleration sensor consists of a seismic square pillar type mass and four beams. This structure was fabricated by reactive ion etching and chemical etching using KOH-etchant. The rectangular square structure is used in order to compensate the deformation of the edges due to underetching. The fabricated sensor showed a linear output voltage-acceleration characteristics and its sensitivity was about $88{\mu}V/V{\cdot}g$ from 0 to 10 G.

• Journal of the Korean Institute of Telematics and Electronics
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• v.21 no.5
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• pp.41-45
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• 1984

The production of high-quality epitaxial layers almost always involves an etching step of silicon substrates with HCl gas prior to epitaxy, In this work, an investigation has been made on the etch rate and the etch-pit formation as a function of HCl gas concentration and etch temperature at atmospheric pressure (1 atm.) and reduced pressure (0.1 atom.). As a result, it is found that the etch rate is proportional to the square of the HCI gas concentration (XHC12) and the apparent ativation energy is between 0 and 111 Kcal/mole for both ammospheric and reduced pressure operation. From these results, it is expected that the HCI etching of silicon in reduced pressure operation proceeds, as in atmospheric operation, via the reaction ; Si + 2HCl ↔ SiCl2 + H2.

• Korean Journal of Materials Research
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• v.34 no.7
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• pp.370-376
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• 2024

In this study, we report significant improvements in lithium-ion battery anodes cost and performance, by fabricating nano porous silicon (Si) particles from Si wafer sludge using the metal-assisted chemical etching (MACE) process. To solve the problem of volume expansion of Si during alloying/de-alloying with lithium ions, a layer was formed through nitric acid treatment, and Ag particles were removed at the same time. This layer acts as a core-shell structure that suppresses Si volume expansion. Additionally, the specific surface area of Si increased by controlling the etching time, which corresponds to the volume expansion of Si, showing a synergistic effect with the core-shell. This development not only contributes to the development of high-capacity anode materials, but also highlights the possibility of reducing manufacturing costs by utilizing waste Si wafer sludge. In addition, this method enhances the capacity retention rate of lithium-ion batteries by up to 38 %, marking a significant step forward in performance improvements.

• Proceedings of the Materials Research Society of Korea Conference
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• 2011.05a
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• pp.37.1-37.1
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• 2011

Miniaturization of lenses has been widely researched by various scientific and engineering techniques. As a result, micro scaled lens structure could be easily achieved from various fabrication techniques; nevertheless it is still challenging to make nano scaled lenses. This paper reports a novel fabrication method of silicon nanotemplate for nanolens array. The inverse structure of nanolens array was fabricated on silicon substrate by reactive ion etching (RIE) process. This technique has a flexibility to produce different tip shapes using different pattern masks. Once the silicon nano-tip array structure is well-defined using an optimized recipe, it is followed by polymer molding to duplicate nanolens array from the template. Finally, the nanostructures formed on silicon nanotemplate and polymer replica were investigated using FE-SEM and AFM measurements. The nano scaled lens can be manufactured from the same template, also using other replication techniques such as imprinting, injection molding and so on.

• Journal of the Korean Society for Precision Engineering
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• v.23 no.3 s.180
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• pp.56-60
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• 2006

A high-resolution shadow mask, or called a nanostencil was fabricated for high resolution lithography. This high-resolution shadowmask was fabricated by a combination or MEMS processes and focused ion beam (FIB) milling. 500 nm thick and $2{\times}2mm$ large membranes wore made on a silicon wafer by micro-fabrication processes of LPCVD, photolithography, ICP etching and bulk silicon etching. A subsequent FIB milling enabled local membrane thinning and aperture making into the thinned silicon nitride membrane. Due to the high resolution of the FIB milling process, nanoscale apertures down to 70 nm could be made into the membrane. By local deposition through the apertures of nanostencil, nanoscale patterns down to 70 nm could be achieved.