• Journal of the Semiconductor & Display Technology
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• v.5 no.2 s.15
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• pp.47-49
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• 2006

Various methods of making thin film is being used in semiconductor manufacturing process. The most common method in this field includes CVD(Chemical Vapor Deposition) and PVD(Physical Vapor Deposition). Thin film is deposited on both the backside and the frontside of wafers. The thin film deposited on the backside has poor thickness profile, and can contaminate wafers in the following processes. If wafers with the thin film remaining on the backside are immersed in batch type process tank, the thin film fall apart from the backside and contaminate the nearest wafer. Thus, it is necessary to etch the backside of the wafer selectively without etching the frontside, and chemical injection nozzle positioned under the wafer can perform the backside etching. In this study, the backside chemical injection nozzle with optimized chemical injection profile is built for single wafer tool. The evaluation of this nozzle, performed on $Si_3N_4$ layer deposited on the backside of the wafer, shows the etching rate uniformity of less than 5% at the etching rate of more than $1000{\AA}$.

• 제어로봇시스템학회:학술대회논문집
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• 2005.06a
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• pp.519-524
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• 2005

A numerical process to simulate SiO2 dry etching with inductively coupled C2F6 plasmas has been constructed using a commercial CFD code as a first step to design a run-to-run control system. The simulator was tuned to reasonably predict the reactive ion etching behavior and used to investigate the effects of plasma operating variables on the etch rate and uniformity. The relationship between the operating variables and the etching characteristics was mathematically modeled through linear regression for future run-to-run control system design.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 1997.10a
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• pp.935-938
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• 1997

Recently, the minimum line width shows a tendency to decrease and the multi-level increase 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. But there are several defects in CMP such as micro-scratches, abrasive contaminations, and non-uniformity of polished wafer edges. Wet etching include of Spin-etching can improve he 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 methods in order to investigate the superiority of wet etching mechanism. In the thin film wafer, the results were evaluated at a viewpoint of material removal rate(MRR) and within wafer non-uniformity(WIWNU). And pattern step height was also compared for planarization characteristics of the patterned wafer.

• Corrosion Science and Technology
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• v.8 no.1
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• pp.15-20
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• 2009

Surface of PEEK(poly-ether-ether-ketone) was modified by chemical etching, plasma treatment and mechanical grinding to improve the plating adhesion. The plating characteristics of these samples were studied by the contact angle, plating thickness, gloss and adhesion. Chemical etching and plasma treatment increased wettability, adhesion and gloss. The contact angle of as-received PEEK was $61^{\circ}$. The contact angles of chemical etched, plasma treated or both were improved to the range of $15{\sim}33^{\circ}$. In the case of electroless plating, the thickest layer without blister was $1.6{\mu}m$. The adhesion strengths by chemical etching, plasma treatment or both chemical etching and plasma treatment were $75kgf/cm^2$, $102kgf/cm^2$, $113kgf/cm^2$, respectively, comparing to the $24kgf/cm^2$ of as-received. In the case of mechanically ground PEEKs, the adhesion strengths were higher than those unground, with the sacrifice of surface gloss. The gloss of untreated PEEK were greater than mechanically ground PEEKs. Plating thickness increased linearly with the plating times.

• Transactions on Electrical and Electronic Materials
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• v.11 no.4
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• pp.174-177
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• 2010

We have developed an environment-friendly etching process, an alternative to the dichromic acid etching process, as a pretreatment of acrylonitrile-butadiene-styrene (ABS) plastic for electroless plating. In order to plate ABS plastic in an electroless way, there should be fine holes on the surface of the ABS plastic to enhance mechanically the adhesion strength between the plastic surface and the plate. To make these holes, the surface was coated uniformly with dispersed chemical foaming agents in a mixture of environmentally friendly dispersant and solvent by the methods of dipping or direct application. The solvent seeps into just below the surface and distributes the chemical foaming agents uniformly beneath the surface. After drying off the surface, the surface was heated at a temperature well below the glass transition temperature of ABS plastic. By pyrolysis, the chemical foaming agents made fine holes on the surface. In order to discover optimum conditions for the formation of fine holes, the mixing ratio of the solvent, the dispersant and the chemical foaming agent were controlled. After the etching process, the surface was plated with nickel. We tested the adhesion strength between the ABS plastic and nickel plate by the cross-cutting method. The surface morphologies of the ABS plastic before and after the etching process were observed by means of a scanning electron microscope.

• The Transactions of the Korean Institute of Electrical Engineers P
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• v.61 no.4
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• pp.225-227
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• 2012

This paper presents a chemical etching system for groove manufacturing for the fluid and aero dynamic bearings. To manufacture the grooves to thrust and journal surface of the fluid and aero dynamic bearing, it is very important for grooves' depth to be smaller tolerance. It is very difficult for the internal surface of journal bearing to make the grooves precise. If the precision of the groove is not exact, we can not get the desirable performance for the target of the dynamic bearing. To make the groove of bearing precise, we propose the method of chemical etching system. It has known that the method of chemical etching can not make the groove on the internal surface of journal bearing excepts for on the surface of thrust bearing. However, this paper has shown the solution to make the grooves on it. We obtain the condition and the parameters of the system such as time, chemical material composition and so on. In this paper, we get the experimental results to verify the precise groove manufacturing for the fluid and aero dynamic bearing.

• Journal of the Korean Crystal Growth and Crystal Technology
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• v.24 no.4
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• pp.135-139
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• 2014

The hydride vapor phase epitaxy (HVPE) grown GaN samples to precisely measure the surface characteristics was applied to a molten KOH/NaOH wet chemical etching. The etching rate by molten KOH/NaOH wet chemical etching method was slower than that by conventional etching methods, such as phosphoric and sulfuric acid etching, which may be due to the formation of insoluble coating layer. Therefore, the molten KOH/NaOH wet chemical etching is a better efficient method for the evaluation of etch pits density. The grown GaN single crystals were characterized by using X-ray diffraction (XRD) and X-ray rocking curve (XRC). The etching characteristics and surface morphologies were studied by scanning electron microscopy (SEM). From etching results, the optimum etching condition that the etch pits were well independently separated in space and clearly showed their shape, was $410^{\circ}C$ and 25 min. The etch pits density obtained by molten KOH/NaOH wet chemical etching under optimum etching condition was around $2.45{\times}10^6cm^{-2}$, which is commercially an available materials.

• 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.30 no.12
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• pp.800-805
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• 2017

Randomly patterned and wet chemical etching processes were used to treat anti-glare of display cover glasses. The surface and optical properties of grain size and surface morphology controlled by randomly patterned etching and wet chemical solution etching were investigated. The surface morphology and roughness of the etched samples were examined using a spectrophotometer and a portable surface roughness (Ra) measuring instrument, respectively. The gloss caused by reflection from the glass surface was measured at $60^{\circ}$ using a gloss meter. The surface of the sample etched by the doctor-blade process was more uniform than that obtained from a screen pattern etching process at gel state etching process of the first step. The surface roughness obtained from the randomly patterned etching process depended greatly on the mesh size, which in turn affected the grain size and pattern formation. The surface morphology and gloss obtained by the etching process in the second step depended primarily on the mesh size of the gel state etching process of the first step. In our experimental range, the gloss increased on decreasing the grain size at a lower mesh size for the first step process and for longer reaction times for the second step process.

• Korean Journal of Metals and Materials
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• v.49 no.10
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• pp.797-804
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• 2011

In this study, the mechanisms of the three steps (the polymer deposition step, the polymer etching step and the Si etching step) that constitute the Bosch process were investigated. The effects of radicals and ions on each step were quantitatively analyzed by comparing the simulated aspect ratio dependency of the deposition or etch rate with the experimental results. In the polymer deposition step, fluorocarbon polymer is deposited by chemical reactions of $CF_x$ radicals, of which the reaction probability is 0.13. Although the polymer etching step and the Si etching step were conducted under the same conditions, the etching mechanisms of polymer and Si were found to be quite different. In the polymer etching step, both chemical etching and physical sputter-etching contribute to the polymer etching. Whereas, in the Si etching step, Si is chemically etched by F radicals, of which the reactivity is greatly increased by the bombardment of energetic ions.