• 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.

• 소성∙가공
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• 제13권3호
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• pp.268-272
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• 2004

Transparent materials such as fused silica are widely utilized 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. In this study, we made a few 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 solution and toluene were used as etchant. In the side of etch rate, toluene solution was better than pyrene-acetone solution. But we made in wider range of energy density using pyrene-acetone solution. But pyrene-acetone solution gave us wider window of energy density for successful micro patterning.

• 공업화학
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• 제20권5호
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• pp.557-560
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• 2009

본 연구에서는 글라스를 $100{\mu}m$ 이하의 두께로 박판화하기 위한 새로운 습식 에칭방법 및 에칭 용액을 검토하였다. $NH_4F$ 또는 $NH_4HF_2$를 주성분으로 황산 또는 질산을 첨가한 경우 에칭 용액의 불산 함유량을 저감하는 데에 효과가 있었다. 혼산 용액의 조성과 온도의 영향을 검토하였으며, 음이온계 계면활성제의 첨가는 에칭반응에 의해 생성되는 슬러지의 부착을 억제해주는 효과가 있었다. 수류 발생부를 가지는 새로운 파일럿 장비를 사용하여 상용 무알칼리 글라스와 소다라임 글라스의 에칭 실험을 실시하였다. $640{\mu}m$ 두께의 무알칼리 글라스를 $45{\mu}m$ 두께로 $500{\mu}m$ 두께의 소다라임 글라스를 $100{\mu}m$ 두께로 박판화하였으며, 에칭 후의 표면 조도는 $0.01{\sim}0.02{\mu}m$를 유지하였다.

• 한국진공학회지
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• 제17권4호
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• pp.353-358
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• 2008

AlGaInP 기반 수직형 적색 LED (Light Emitting Diode)의 광추출효율을 증가시키기 위하여 화학적 etching 기술을 이용하여 n-AlGaInP 표면에 삼각꼴 모양의 거칠기를 형성하였다. Etching은 $H_3PO_4$계의 용액을 이용하여 화학적 etching을 진행 하였다. AlGaInP etching은 광추출효율의 증가와 밀접한 관련을 갖고 있으며 AFM (Atomic Force Microscope)을 이용하여 AlGaInP 표면을 분석하여 약 44 nm의 RMS (root-mean-square) 거칠기가 형성됨을 알 수 있었다. 광추출효율은 기존 수직형 적색 LED보다 거칠기가 형성된 수직형 적색 LED에서 41%의 높은 발광 효율을 보임으로써 고효율 수직형 적색 LED의 가능성을 보였다.

• Current Photovoltaic Research
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• 제5권3호
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• pp.75-82
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• 2017

High efficiency thin film solar cells require an absorber layer with high absorption and low defect, a transparent conductive oxide (TCO) film with high transmittance of over 80% and a high conductivity. Furthermore, light can be captured through the glass substrate and sent to the light absorbing layer to improve the efficiency. In this paper, morphology formation on the surface of glass substrate was investigated by using HF, mainly classified as random etching and periodic etching. We discussed about the etch mechanism, etch rate and hard mask materials, and periodic light trapping structure.

• 한국전기전자재료학회논문지
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• 제18권12호
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• pp.1106-1110
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• 2005

We fabricated (110) silicon hard master by using anisotropic wet etching for embossing. The etching chemical for the silicon wafer was a TMAH $25\%$ solution. The anisotropic wet etching produces a smooth sidewall surface and the surface roughness of the fabricated master is about 3 nm. After spin coating an organic-inorganic sol-gel hybrid material on a silicon substrate, we employed hot embossing technique operated at a low pressure and temperature to form patterns on the silicon substrate by using the fabricated master. We successfully fabricated the multi-mode planar optical waveguides showing low propagation loss of 0.4 dB/cm. The surface roughness of embossed patterns was uniform for more than 10 times of the embossing processes with a single hydrophobic surface treatment of the silicon hard master.

• 대한전기학회:학술대회논문집
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• 대한전기학회 1996년도 추계학술대회 논문집 학회본부
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• pp.248-250
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• 1996

VTR 자기헤드의 핵심소재로 사용되는 ferrite는 VTR 의 주기능인 영상의 기록 및 재생역할에 가장 중요한 소재이다. 이러한 종류의 head는 지금까지 mask wet chemical etching과 mechanical Process 에 의해 제작 되어왔다. 그러나 기록용량의 중가로 자기장치의 recording density를 높일것이 요구됨에 따라 자기헤드의 gap width를 줄일 필요가 있게 되었다. 본 연구는 mask와 photoresist를 사용하지 않고 ferrite를 직접 미세가공 하는 laser-induced wet etching을 이용하여 자기헤드의 기록용량을 높이고자 하였다. $Ar^+$ laser ( 파장 514 nm )를 빔 확장기와 렌즈를 사용 하여 직경 $1.8{\mu}m$ 로 집속하고, $100{\sim}500\;mW$의 출력 변화를 주어 실험을 하였다. 인산 수용액 (45, 65, 85 %)을 etchant로 사용하여 $5{\sim}30{\mu}m/sec$의 주사속도로 etching 하여, 미세선폭과 high aspect ratio를 갖는 groove를 얻을 수 있었다.

• 한국염색가공학회지
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• 제22권2호
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• pp.123-131
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• 2010

Shape and size controlled synthesis of gold particles has been studied by using wet-chemical method. When ${AuCl_4}^-$ in aqueous $HAuCl_4$ precursor was reduced using $Na_2SO_3$ as a reducing agent, mixtures of spherical, triangular and hexagonal particles were prepared in a few minutes. It was found that the shape selective oxidative etching by ${AuCl_4}^-\;+\;Cl^-$ anions and crystal growth took place simultaneously. As the ${AuCl_4}^-$ and $Cl^-$ concentration increased, yields of large triangular and hexagonal plate type particles increased, while the spherical particles decreased in most cases. Possible etching and growth mechanisms are discussed.

• 한국전기전자재료학회논문지
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• 제24권2호
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• pp.152-155
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• 2011

Even though nano-scale materials were very advantageous for various applications, there are still problems to be solved such as the stabilization of surface state and realization of low contact resistances between a semiconducting nanowire and electrodes in nano-electronics. It is well known that the effects of contacts barrier between nano-channel and metal electrodes were dominant in carrier transportation in individual nano-electronics. In this report, it was investigated the electrical properties of GaN nanorod devices after chemical etching and rapid thermal annealing for making good contacts. After KOH wet-etching of the contact area the devices showed better electrical performance compared with non-treated GaN individual devices but still didn't have linear voltage-current characteristics. The shape of voltage-current properties of GaN devices were improved remarkably after rapid thermal annealing as showing Ohmic behaviors with further bigger conductivities. Even though chemical etching of the nanorod surfaces could cause scattering of carriers, in here it was shown that the most important and dominant factor in carrier transport of nano-electronics was realization of low contact barrier between nano-channel and metal electrodes surely.

• 한국진공학회:학술대회논문집
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• 한국진공학회 2016년도 제50회 동계 정기학술대회 초록집
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• pp.243.1-243.1
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• 2016

Recently, many groups have attempted to fabricate 3-dimensional (3D) structures of GaN such as pyramids, rods, stripes and annulars. Since quantum structures on non-polar and semi-polar planes of 3D structures have less influence of internal electric filed, multi quantum wells (MQWs) formed on those planes have high quantum efficiency. Especially, pyramidal and annular structures consist of various crystal planes with different emission wavelength, providing a possibillity of phosphor-free white light emtting diodes (WLEDs).[1] However, it still has problem to obtain high color rendering index (CRI) number because of narrow-band emission and poor indium composition caused by the formation of few number of facets during metal-organic chemical vapor deposition growth.[2] If we can fabricate 3D structure having more various facets, we can make broad-band emittied WLEDs and improve CRI number. In this study, we suggest a simple method to fabricate 3D structures having various facet and containing high indium composition by means of a combination of metal-organic chemical vapor deposition and wet chemical etching techniques.