• 한국광학회:학술대회논문집
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• 한국광학회 2009년도 동계학술발표회 논문집
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• pp.133-134
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• 2009

Cold temperature development (CTD) of electron beam (EB) patterned resists and subsequent dry etching were investigated for fabrication of nano-patterned Niobium (Nb). Bulky Nb fims on GaAs substrates were deposited with EB evaporation. Line patterns on Nb cathode were fabricated by EB patterning and reactive ion etching (RIE). Size deviations of nano-sized line patterns from CAD designed patterns are dependent on the EB total exposure, but it can be improved by CTD of EB-exposed resist. Line patterns of 10 to 300 nm widths of EB-exposed resist patterns were drawn under various exposure conditions of $0.2{\mu}s$/dot (total 240,000 dot) with a constant current (50 pA). Compared with room temperature development (RTD), the CTD improves pattern resolution due to the suppression of backscattering effect. RIE with $CF_4$ was performed for formation of several nano-sized line patterns on Nb. Each EB-resist patterned samples with RTDs and CTDs were etched with two different $CF_4$ gas pressures of 5 Pa. Nb etching rate increases while GaAs (or ZEP) etching rate decreases as the chamber pressure increases. This different dependent of the etching rate on the $CF_4$ pressure between Nb and GaAs (or ZEP) has a significant meaning because selective etching of nano-sized Nb line patterns is possible without etching of the underlying active layer.

• 전자공학회논문지
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• 제51권8호
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• pp.167-171
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• 2014

평판 디스플레이(plate panel display)가 휴대용으로 발전하면서 박막화, 고색재현성, 고휘도에 관한 연구가 활발히 이루어지고 있으며, 광원으로써 LED, OLED가 주로 이용되고 있다. 이러한 광원의 소재로 양자점에 관한 연구가 많이 이루어 지고 있는데, 양자점은 고색재현성과 유연디스플레이 구현에 있어서 주목받는 차세대 반도체 나노형광체 이다. 본 연구에서는 평판 디스플레이를 구현함에 있어서 양자점을 이용하는 방법에 관하여 제시하였다. CdSe/ZnS 양자점을 PET베리어 필름에 $100{\mu}m$ 두께로 도포하고 455nm의 파장을 갖는 청색 LED를 광원으로하여 빛을 조사하는 디바이스를 제작하고 광특성을 평가하였으며, LCD의 색변환 필름으로써 양자점의 적용 가능성을 제시하였다.

• 한국전기전자재료학회논문지
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• 제18권12호
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• pp.1069-1074
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• 2005

In this work, nano-needle structures ate formed to solve problem, related to low density of quantum dots for nano floating gate memory. Such structures ate fabricated and electrical properties' of MIS devices fabricated on the nano-structures are studied. Nano floating gate memory based on quantum dot technologies Is a promising candidate for future non-volatile memory devices. Nano-structure is fabricated by reactive ion etching using $SF_6$ and $O_2$ gases in parallel RF plasma reactor. Surface morphology was investigated after etching using scanning electron microscopy Uniform and packed deep nano-needle structure is established under optimized condition. Photoluminescence and capacitance-voltage characteristics were measured in $Al/SiO_2/Si$ with nano-needle structure of silicon. we have demonstrated that the nano-needle structure can be applicable to non-volatile memory device with increased charge storage capacity over planar structures.

• 한국정밀공학회지
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• 제24권11호
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• pp.108-115
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• 2007

We have designed a high transmission C-shaped aperture using finite differential time domain (FDTD) technique. The C-shaped aperture was fabricated in the aluminum thin film on a glass substrate using a focused ion beam (FIB) milling. Nano-size patterning was demonstrated with a vacuum contact device to keep tight contact between the Al mask and the photoresist. Using 405 nm laser, we recorded a 50 nm-size dot pattern on the photoresist with the aperture and analyzed the spot size dependent on the dose illuminated on the aperture.

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 2005년도 추계학술대회 논문집 Vol.18
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• pp.128-129
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• 2005

In this research, non-volatile memory effects and nano-crystal creation have been investigated in SiNx containing Si nano-crystals (Si-nc) produced by ICP-CVD and rapid thermal annealing. The quantum dots were created during rapid thermal annealing of Si-rich SiNx thin films. The quantum dot creation was analyzed with photoluminescence spectra, and in case of Si-rich SiNx, it is conformed that the quantum dots are formed easily at 750$\sim$800nm wavelength.

• 한국표면공학회:학술대회논문집
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• 한국표면공학회 2009년도 추계학술대회 초록집
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• pp.247-247
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• 2009

본 연구에서는 indium-tin oxide (ITO) 나노 입자 용액을 이용하여 간단한 공정을 통해 ITO 나노 패턴을 직접적으로 제작하는 기술에 대한 연구를 진행하였다. 이를 이용하여 300nm급 ITO 나노 dot 패턴을 제작하는데 성공하였으며 이를 glass 표면에 구현하는데 성공하였다.

• 한국진공학회:학술대회논문집
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• 한국진공학회 2012년도 제42회 동계 정기 학술대회 초록집
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• pp.191-191
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• 2012

InP quantum dot (QD) - organosilicon nanocomposites were synthesized and their photoluminescence quenching was mainly investigated because of their applicability to white LEDs (light emitting diodes). The as-synthesized InP QDs which were capped with myristic acid (MA) were incompatible with typical silicone encapsulants. Post ligand exchange the MA with a new ligand, 3-aminopropyldimethylsilane (APDMS), resulted in soluble InP QDs bearing Si-H groups on their surface (InP-APDMS) which allow embedding the QDs into vinyl-functionalized silicones through direct chemical bonding, overcoming the phase separation problem. However, the ligand exchange from MA to APDMS caused a significant decrease in the photoluminescent efficiency which is interpreted by ligand induced surface corrosion relying on theoretical calculations. The InP-APDMS QDs were cross-linked by 1,4-divinyltetramethylsilylethane (DVMSE) molecules via hydrosilylation reaction. As the InP-organosilicon nanocomposite grew, its UV-vis absorbance was increased and at the same time, the PL spectrum was red-shifted and, very interestingly, the PL was quenched gradually. Three PL quenching mechanisms are regarded as strong candidates for the PL quenching of the QD nano-composites, namely the scattering effect, Forster resonance energy transfer (FRET) and cross-linker tension preventing the QD's surface relaxation.

• 한국진공학회:학술대회논문집
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• 한국진공학회 2014년도 제46회 동계 정기학술대회 초록집
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• pp.298-298
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• 2014

Quantum dot infrared photodetectors (QDIPs) based on Stranski-Krastanov (SK) quantum dots (QDs) have been widely explored for improved device performance using various designs of heterostructures. However, one of the biggest limitations of this approach is the "pancake" shape of the dot, with a base of 20-30 nm and a height of 4-6 nm. This limits the 3D confinement in the quantum dot and reduces the ratio of normal incidence absorption to the off-axis absorption. One of the alternative growth modes to the formation of SK QDs is a sub-monolayer (SML) deposition technique, which can achieve a much higher density, smaller size, better uniformity, and has no wetting layer as compared to the SK growth mode. Due to the advantages of SML-QDs, the SML-QDIP design has attractive features such as increased normal incidence absorption, strong in-plane quantum confinement, and narrow spectral wavelength detection as compared with SK-DWELL. In this study, we report on the improved device performance of InAs/InGaAs SML-QDIP with different composition of $Al_xGa1-_xAs$ barrier. Two SML-QDIPs (x=0.07 for sample A and x=0.20 for sample B) are grown with the 4 stacks 0.3 ML InAs. It is investigated that sample A with a confinement-enhanced (CE) $Al_{0.22}Ga_{0.78}As$ barrier had a single peak at $7.8{\mu}m$ at 77 K. However, sample B with an $Al_{0.20}Ga_{0.80}As$ barrier had three peaks at (${\sim}3.5{\mu}m$, ${\sim}5{\mu}m$, ${\sim}7{\mu}m$) due to various quantum confined transitions. The measured peak responsivities (see Fig) are ~0.45 A/W (sample A, at $7.8{\mu}m$, $V_b=-0.4V$ bias) and ~1.3 A/W (sample B, at $7{\mu}m$, $V_b=-1.5V$ bias). At 77 K, sample A and B had a detectivity of $1.2{\times}10^{11}cm.Hz^{1/2}/W$ ($V_b=-0.4V$ bias) and $5.4{\times}10^{11}cm.Hz^{1/2}/W$ ($V_b=-1.5V$ bias), respectively. It is obvious that the higher $D^*$ of sample B (than sample A) is mainly due to the low dark current and high responsivity.

• 한국진공학회지
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• 제20권1호
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• pp.7-13
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• 2011

자기조립화된 Fe/Au 이중층 위에 $L1_0$형 구조를 갖는 FePd 나노 점을 성공적으로 제작하였다. AFM를 이용하여 초기에 편평한 Fe/Au 이중층 박막이 온도가 증가함에 따라서 응집되어 나노 점 구조로 변형되는 것을 확인하였다. 또한 형성된 이중층위에 FePd 다층막을 $300^{\circ}C$, $350^{\circ}C$, $400^{\circ}C$, $450^{\circ}C$에서 각각 증착하였다. 초격자 구조를 갖는 FePd 다층막의 표면형상은 응집현상에 의하여 자기조립화된 이중층의 형상과 유사하였다. XRD 측정결과, $350^{\circ}C$ 이상에서 열처리된 FePd 다층막은 $L1_0$형 구조를 갖는다는 것을 확인하였다. 그리고 박막두께에 따른 XPS 측정결과는 전체 박막의 화학적 조성이 증착순서와 일치하는 것을 보여주었다. 결과적으로 추가적인 식각공정 없이 화학적으로 규칙화된 FePd 초격자 나노 점의 제작에 성공하였다.

• 한국융합학회논문지
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• 제6권2호
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• pp.49-55
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• 2015

양자점 기술은 나노연구 관점에서 벌크 재료에 대한 보완적 응용과 고유한 특성을 활용한 응용의 폭이 넓어 융합기술로서 의미가 크다. 양자점 기술의 발전과 더불어 기술성, 사업성, 시장성에 기반한 현황 분석이 매우 중요하고, 이에 본 연구는 특허, 논문, 시장 및 산업, 국가 R&D 과제 정보를 활용한 4P 분석 방법을 적용하여 양자점 연구의 동향을 파악하고자 한다. 연구의 결과물은 양자점 연구의 방향 설정, 전략 수립에 활용될 수 있는 기초 정보를 제공한다. 특히 특허와 논문 분석을 통해 양자점 연구 성과를 파악하고, 급격한 성장세를 보이는 응용 분야와 사업화를 견인하고 있는 응용 분야를 도출하였다. 또한 선진 연구와 국내 연구 동향을 비교하여 국내 양자점 연구 현황을 진단할 수 있는 초석을 제공하였다는 점에서 본 연구가 의미를 갖는다.