• 한국세라믹학회지
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• 제37권1호
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• pp.82-89
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• 2000

In lithium silicate photosensitive glass-ceramics, the relationship between lithography time and crystallization, and the effect of addition of mineral acid in etching rate and pattern shape were investigated. Irradiation times for micropatterning were less than 5 minutes in which Ce3+ ions in glass were changed rapidly to Ce4+ with ultra violet light. Overexposure to ultra brought about blot of pattern by diffiraction of light. Addition of mineral acid to HF enhanced etching rate as compared with HF solution only. The addition of H2SO4 especially increased the etching rate by 70%. But the mixed solution also increased the etching rate of the noncrystallized portion of the glass and this resulted in heavy etching. Etching with ultrasonic wave showed higher etching rate than that with the static or fluid method.

• 한국전기전자재료학회논문지
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• 제30권12호
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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.

• 멤브레인
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• 제23권1호
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• pp.92-99
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• 2013

본 연구는 인쇄회로기판(PCB) 제조 시 에칭공정에서 발생되는 구리이온($Cu^{+2}$)을 고농도로 함유한 황산 폐에칭액을 NF 막분리법을 사용하여 에칭액 회수와 구리이온 처리를 효율적으로 수행하기 위한 NF 막여과 공정의 운전 조건을 설정하기 위한 기본 자료를 확보하는데 있다. 이를 위해 미국 Koch사의 SelRO MPS-34 4040 NF 막을 대상으로 구리이온을 고농도(5~25 g/L)로 함유한 모의 황산 폐에칭액의 회분식(dead-end) 나노여과 실험을 수행하여 투과 플럭스와 구리이온의 총괄 배제도를 측정하였다. 이 결과 황산용액에의 막 보관기간이 길수록, 황산용액의 pH가 낮을수록 황산에 의한 NF 막의 손상이 더 크게 발생하여 순수 투과 플러스가 증가하였다. 황산 폐에칭액의 투과 플럭스는 황산용액 내 구리이온의 농도가 증가할수록 막 표면에의 구리이온 농축(농도분극)의 증가에 따라 감소하였으며, 구리이온의 배제도는 구리이온의 농도가 높을수록, pH가 낮을수록, 황산용액 내의 막 보관기간이 길수록 낮아져 초기 37%에서 최소 15% 수준으로까지 감소하였다.

• Journal of Electrochemical Science and Technology
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• 제11권4호
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• pp.330-335
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• 2020

Silicon surface nanostructures, which can be easily prepared by electrochemical etching, have attracted considerable attention because of its useful physical properties that facilitate application in diverse fields. In this work, electrochemical and electrochemical-scanning tunneling microscopic (EC-STM) techniques were employed to study the evolution of surface morphology during the electrochemical etching of Si(111)-H in a fluoride solution. The results exhibited that silicon oxide of the Si(111) surface was entirely stripped and then the surface became hydrogen terminated, atomically flat, and anisotropic in the fluoride solution during chemical etching. At the potential more negative than the flat band one, the surface had a tendency to be eroded very slowly, whereas the steps of the terrace were not only etched quickly but the triangular pits also deepened on anodic potentials. These results provided information on the conditions required for the preparation of porous nanostructures on the Si(111) surface, which may be applicable for sensor (or device) preparation (Nanotechnology and Functional Materials for Engineers, Elsevier 2017, pp. 67-91).

• 한국전기전자재료학회논문지
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• 제28권9호
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• pp.607-614
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• 2015

To provide the clear images from the direct light on electrical board and display devices, anti glare treatment of display cover glass is needed. In this study, the effects of surface treatment temperature, concentration, and etching solution coating thickness of the gel phase on optical elements control such as gloss, haze of reflected light and transmittance, were investigated. Cover glasses were treated at different coating thickness and additive concentration. The optical properties were examined using spectrophotometer, gloss and haze meter. The surface morphology and roughness were measured by the optical microscope and Ra measuring instrument. The etching rate and surface morphologies were dramatically affected by the concentration of acid additive in the viscous gel because of re-crystallization of components in the etching solution, hydrogel formation and coagulant after coating on glass substrate. In our experimental range, cover glass which is surface-treated with various optical properties as well as the morphology uniformity was obtained; in particular, optical properties could be controlled by etching solution coating thickness of the gel phase and the concentration of additive. The gloss was depended on the surface roughness and it showed the linear relationship between optical transmittance and haze of reflected light, respectively.

• 반도체디스플레이기술학회지
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• 제2권4호
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• pp.37-40
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• 2003

반도체 장비의 기능성과 신뢰성을 높이기 위하여 부품의 제조기술은 점차 마이크로 머신 기술을 요구하고 있다. 마이크로머신 기술 중 hot junction이 위치하는 멤브레인 구조는 각종 센서와 히터의 미세부품에서 가장 이용도가 큰 구조이다. 실험에서는 마이크로머신의 기본 구조인 멤브레인 형태를 만들기 위해 KOH 용액과 TMAH 용액으로 단결정 실리콘을 이방성 습식식각 하였다. 실험결과, 식각액의 온도와 농도, 마스크 패턴과 웨이퍼의 결정성의 일치 등을 고려해야 하며, 식각 속도는 KOH 농도 및 온도에 따라 크게 변함을 알 수 있었다. KOH 용액은 30 wt% 80~$90^{\circ}C$ 온도 범위에서 가장 좋은 특성을 나타냈다. 한편, TMAH용액이 실리콘을 식각하는 용액으로 관심을 끄는 것은 단결정에서 상대적으로 $SiO_2$ 박막을 마스크로 사용할 수 있을 뿐 아니라 $SiO_2$ 박막을 마스크로 사용할 수 있을 뿐 아니라 다른 식각액보다 찌꺼기가 적다는 장점 때문이다. 그러나, 다른 용액에 비해 가격이 고가이며 식각 속도가 낮다는 것이 실용적인 측면에서 큰 단점이다. 실험결과를 종합적으로 고려할 때 KOH 용액 농도 30wt%와 온도 $90^{\circ}C$가 마이크로머신 기술에 의한 멤브레인 구조 제작에서 적합한 공정조건이라고 할 수 있다.

• 한국표면공학회지
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• 제49권3호
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• pp.301-306
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• 2016

The effects of nanotexturing and post-etching on the reflection and quantum efficiency properties of diamond wire sawn (DWS) multicrystalline silicon (mc-Si) solar cell have been investigated. The chemical solutions, which are acidic etching solution (HF-$HNO_3$), metal assisted chemical etching (MAC etch) solutions ($AgNO_3$-HF-DI, HF-$H_2O_2$-DI) and post-etching solution (diluted KOH at $80^{\circ}C$), were used for micro- and nano-texturing at the surface of diamond wire sawn (DWS) mc-Si wafer. Experiments were performed with various post-etching time conditions in order to determine the optimized etching condition for solar cell. The reflectance of mc-Si wafer texturing with acidic etching solution showed a very high reflectance value of about 30% (w/o anti-reflection coating), which indicates the insufficient light absorption for solar cell. The formation of nano-texture on the surface of mc-Si contributed to the enhancement of light absorption. Also, post-etching time condition of 240 s was found adequate to the nano-texturing of mc-Si due to its high external quantum efficiency of about 30% at short wavelengths and high short circuit current density ($J_{sc}$) of $35.4mA/cm^2$.

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 2000년도 춘계학술대회 논문집 전자세라믹스 센서 및 박막재료 반도체재료 일렉트렛트 및 응용기술
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• pp.112-116
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• 2000

This paper presents anisotropic ethcing characteristics of single-crystal silicon in tetramethylammonium hydroxide(TMAH):isopropyl alcohol(IPA) solutions containing pyrazine. With the addition of IPA to TMAH solutions, etching characteristics are exhibited that indicate an improvement in flatness on the etching front and a reduction in undercutting, but the etch rate on (100) silicon is decreased. The (100) silicon etch rate is improved by the addition of pyrazine. An etch rate on (100) silicon of $0.8\;{\mu}m/min$, which is faster by 13 % than a 20 wt.% solution of pure TMAH, is obtained using 20 wt.% TMAH:0.5 g/100 ml pyrazine solutions, but the etch rate on (100) silicon is decreased if more pyrazine is added. With the addition of pyrazine to a 25 wt.% TMAH solution, variations in flatness on the etching front were not observed and the undercutting ratio was reduced by 30 ~ 50 %.

• 대한전기학회논문지
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• 제36권9호
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• pp.636-639
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• 1987

In this study, we investigate the etching characteristics of a-Se75 Ge25 thin films. Etching properties are revealed as a function of obliqueness, temperature and concentraction of the etching solution. As the increase of obliqueness, selective etching effect increase rapidly by 35% at 80 obliqueness, and the etching rate increase the elevated temperature of the solution. The change of etching rate with obliqueness are related closely to the optical change due to the band gap illumination. We obtained clear pattern of 1.5um linewidth.

• 한국세라믹학회지
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• 제34권10호
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• pp.1021-1026
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• 1997

RuO2 thin film has reasonably good conductivity and stiffness and it is thought to substitute for the cantilever beam made up of Pt and Si3N4 double layers in microactuators. Therefore, anisotopic Si etching was performed using RuO2 thin film as a mask layer in 25 wt. % TMAH water solution. In the etching temperature ranging from 6$0^{\circ}C$ to 75$^{\circ}C$, the etch rates of all the crystallographic directions increased linearly as the etching temperature increased. The etch rate ratio(selectivity) of [111]/[100] which varied from 0.08 to 0.14, was not sensitive to temperature. The activation energies for [110] direction, [100] direction and [111] direction were 0.50, 0.66 and 1.04eV, respectively. RuO2 cantilever beam with a clean surface was formed at the etching temperatures of 6$0^{\circ}C$ and $65^{\circ}C$. But the damages due to formation of pin holes on RuO2 surface were observed beyond 7$0^{\circ}C$. The tensile stress of RuO2 thin films caused the cantilever bending upward. As a result, it was demonstrated that the formation of conducting oxide RuO2 cantilever beam which can replace the role of an electrode and supporting layer could be possible by TMAH solution.