• 마이크로전자및패키징학회지
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• 제27권3호
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• pp.9-19
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• 2020

기능성 나노박막을 손상 없이 목표기판으로 옮기는 전사 기술은 나노박막 기반의 차세대 응용 제품 개발을 위한 초석이다. 본 논문에서는 최근 나노박막 전사의 연구 동향을 박막-기판 계면의 박리 원리에 따라 습식 식각 전사, 전기화학적 박리, 기계식 전사 방법 세 가지로 분류하여 간단하게 살펴볼 것이다. 더 나아가, 손쉽고, 기판 재활용이 가능하며, 광범위한 적용 가능성을 가지고 있어 유망 기술로 간주되는 기계식 전사 방법에 대하여 파괴 역학적 관점에 초점을 맞추어 다룰 것이다. 마지막으로, 나노박막의 기계식 전사 방법의 기술 성숙도를 향상시키기 위한 향후 도전 과제와 방향성에 대하여 고찰하고자 한다.

• 한국전자파학회논문지
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• 제28권1호
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• pp.25-32
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• 2017

본 논문에서는 플루오린화 수소산(hydrofluoric acid)과 표면 장력을 이용한 손실이 낮은 광섬유형 방향성 결합기 제작 방법을 제안한다. 제안한 방향성 결합기 제작 방법은 기존에 일반적으로 이용하던 열원을 이용한 제작 방법과는 다르게 다양한 장비들이 요구되지 않으며, 마멸을 이용한 방법보다 손실이 낮으며, 제작 과정이 매우 쉽다. 또한, 제작된 결과물은 테이퍼드(tapered) 형태의 아디아바틱(adiabatic)한 구조로 인해 광통신에서 널리 이용되는 C-band 영역에서 파장 의존성이 낮아 광통신에서 유망한 역할을 맡을 수 있다.

• 한국광학회지
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• 제6권2호
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• pp.148-155
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• 1995

저손실의 단일모드 $Al_{0.042}Ga_{0.958}As/GaAs/Al_{0.042}Ga_{0.958}As$ strip-loaded 도파로들이 유효굴절률 방법으로 설계되고 MOCVD 성장기법과 화학적인 습식 식각방법으로 제작되었다. 제작된 도파로의 전파손실과 도파로 단면의 반사율은 $1.31{\mu}m$ 파장에서 Fabry-Perot 공명방법과 연속적인 절단 실험을 이용하여 측정되었다. 실험결과 폭이 $ w=4.1{\mu}m$인 직선 도파로에 대해 전파손실은 0.62dB/cm로 작았으며 도파로의 반사율은 0.299가 되었다.

• 한국재료학회지
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• 제23권6호
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• pp.322-328
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• 2013

The relationship the between electrical properties and surface roughness (Ra) of a wet-etched silicon wafer were studied. Ra was measured by an alpha-step process and atomic force microscopy (AFM) while varying the measuring range $10{\times}10$, $40{\times}40$, and $1000{\times}1000{\mu}m$. The resistivity was measured by assessing the surface resistance using a four-point probe method. The relationship between the resistivity and Ra was explained in terms of the surface roughness. The minimum error value between the experimental and theoretical resistivities was 4.23% when the Ra was in a range of $10{\times}10{\mu}m$ according to AFM measurement. The maximum error value was 14.09% when the Ra was in a range of $40{\times}40{\mu}m$ according to AFM measurement. Thus, the resistivity could be estimated when the Ra was in a narrow range.

• 한국재료학회지
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• 제23권6호
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• pp.316-321
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• 2013

The electrical properties and surface morphology changes of a silicon wafer as a function of the HF concentration as the wafer is etched were studied. The HF concentrations were 28, 30, 32, 34, and 36 wt%. The surface morphology changes of the silicon wafer were measured by an SEM ($80^{\circ}$ tilted at ${\times}200$) and the resistivity was measured by assessing the surface resistance using a four-point probe method. The etching rate increased as the HF concentration increased. The maximum etching rate 27.31 ${\mu}m/min$ was achieved at an HF concentration of 36 wt%. A concave wave formed on the wafer after the wet etching process. The size of the wave was largest and the resistivity reached 7.54 $ohm{\cdot}cm$ at an 30 wt% of HF concentration. At an HF concentration of 30 wt%, therefore, a silicon wafer should have good joining strength with a metal backing as well as good electrical properties.

• 한국진공학회:학술대회논문집
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• 한국진공학회 2011년도 제40회 동계학술대회 초록집
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• pp.175-175
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• 2011

인체감지 적외선 센서로 사용되는 마이크로볼로미터 센서 감지재료인 $V_{2-x}W_xO_5$를 증착하고 단위소자를 제작하여 저항 및 센서성능을 측정 조사하였다. 감지재료는 $V_2O_5$에 W을 첨가하여 $V_{2-n}W_nO_5$ 타겟을 제작하였으며 RF sputtering 장비를 이용하여 $V_{1.85}W_{0.15}O_5$ 박막을 증착하였다. 증착온도 $400^{\circ}C$, $Ar/O_2$ 가스비율 50/20, 두께 200nm로 증착된 센서 재료의 특성을 조사한 결과 저항은 약 $20{\sim}70k{\Omega}$이었으며, TCR 값은 -3%/$^{\circ}C$ 이상으로 매우 우수한 박막특성을 얻었다. 볼로미터소자는 $40{\times}40{\sim}140{\times}140um^2$의 셀면적으로 설계하여 전극패턴과 습식식각공정으로 센서 구조체를 제작하였다. 소자의 성능평가는 검출기 측정장비를 이용하여 반응도 및 탐지도 특성을 조사하였다.

• 한국재료학회지
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• 제16권1호
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• pp.63-67
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• 2006

The characteristics of the wet-etching of ZnO thin films were investigated using hydrochloric and phosphoric acid solutions as etchants. The etch rate of ZnO films, using highly diluted hydrochloric acid solutions at a concentration of 0.25% in deionized water, was determined to be about 120 nm/min, and linearly increased with increasing the acid concentration, resulting in $1.17{\mu}m/min$ when a 2% HCl solution was used. The surface of ZnO etched by an HCl solution, observed by scanning electron microscopy, showed a rough morphology with a high density of hexagonal pyramids or cones with sidewall angles of about ${\sim}45^{\circ}C$. Moreover, the sidewall angles of the masked area were similar to those of the pyramids on the surface. In comparison, the surface of ZnO etched by a phosphoric acid had a smooth surface morphology. The origin of this difference is from the very initial stage of etching, indicating that the etch-mechanism is different for each solution. Furthermore, when $H_3PO_4$ was added to the HCl aqueous solution, the morphology of the etched surface was greatly enhanced and the sidewall angle was also increased to about $65^{\circ}C$.

• 한국전기전자재료학회논문지
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• 제15권2호
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• pp.105-109
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• 2002

The wet etching characteristics of magnetic materials such as NiFe and CoFe were investigated in terms of etch rate and etch profile by using variouus etching solutions (etchants). Among the various etching solutions, HNO$_3$, HCl, and H$_2$SO$_4$were selected for the etching of magnetic materials and showed distinct results. In the case of NiFe films, faster etch rate were obtained with HNO$_3$solution. When NiFe films ere etched with HCl solution, white etch residues were found on the surface of etched films. From FEAES analysis of these etch residues, they were proved to be by-product from the reaction of NiFe with Cl element. CoFe thin films showed the similar trend to the case of NiFe films. They were etched fast in HNO$_3$ solution while Chl solution represented slow etching. The etch profiles of CoFe films showed smooth etch profile but revealed the partial etching around the patterns in HNO$_3$solution of relatively high concentration. It was observed that the etched surface was clean and smooth, and that white etch residues were also remained on the etched films.

• 한국재료학회지
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• 제19권5호
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• pp.259-264
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• 2009

In this study we investigated the effect of the multi-step texturing process on the electrical and optical properties of hydrogenated Al-doped zinc oxide (HAZO) thin films deposited by rf magnetron sputtering. AZO films on glass were prepared by changing the $H_2/(Ar+H_2)$ ratio at a low temperature of $150^{\circ}C$. The prepared HAZO films showed lower resistivity and higher carrier concentration and mobility than those of non-hydrogenated AZO films. After deposition, the surface of the HAZO films was multi-step textured in diluted HCl (0.5%) for the investigation of the change in the optical properties and the surface morphology due to etching. As a result, the HAZO film fabricated under the type III condition showed excellent optical properties with a haze value of 52.3%.

• 반도체디스플레이기술학회지
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• 제14권3호
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• pp.7-11
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• 2015

In order to protect the patterned mask from contamination during lithography process, pellicle has become a critical component for Extreme Ultraviolet (EUV) lithography technology. According to EUV pellicle requirements, the pellicle should have high EUV transmittance and robust mechanical property. In this study, silicon nitride, which is well-known for its remarkable mechanical property, was used as a pellicle membrane material to achieve high EUV transmittance. Since long silicon wet etching process time aggravates notching effect causing stress concentration on the edge or corner of etched structure, the remaining membrane is prone to fracture at the end of etch process. To overcome this notching effect and attain high transmittance, we began preparing a rather thick (200 nm) $SiN_x$ membrane which can be stably manufactured and was thinned into 43 nm thickness with HF wet etching process. The measured EUV transmittance shows similar values to the simulated result. Therefore, the result shows possibilities of HF thinning processes for $SiN_x$ EUV pellicle fabrication.