• 한국전기전자재료학회논문지
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• 제20권10호
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• pp.864-868
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• 2007

Effect of high-temperature annealing on morphology of fully coherent self-assembled InAs quantum dots' grown on Si (100) substrates at $450^{\circ}C$ by atmospheric pressure metalorganic chemical vapor deposition(APMOCVD) was investigated by atomic force microscopy(AFM). When the dots were annealed at 500 - 600$^{\circ}C$ for 15 sec - 60 min, there was no appreciable change in the dot density but the heights of the dots increased along with the reduction in the diameters. In segregation from the InAs quantum dots and/or from the 2-dimensional InAs wetting layer which was not transformed into quantum dots looked responsible for this change in the dot size. However the change rates remained almost same regardless of annealing time and temperature, which may indicate that the morphological change due to thermal annealing is done instantly when the dots are exposed to high temperature annealing.

• Composites Research
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• 제37권3호
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• pp.170-178
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• 2024

본 연구에서는 탄소섬유 강화 플라스틱(CFRP)에 얇은 구리 필름(Cu film)이 배치된 hybrid composite이 제안되었으며, 두께방향 열전도도가 최대가 될 수 있는 Cu film 배치조합을 도출하는데 양자 어닐링(Quantum Annealing)이 적용되었다. CFRP의 각 ply와 Cu film간의 상관관계 분석이 유한요소 해석을 통해 수행되었으며, 수행된 결과를 바탕으로 조합 최적화 문제가 정의되었다. 정의된 문제를 양자 어닐링에 임베딩하기 위한 공식화 과정이 진행되었으며 이를 통해 CFRP의 각 ply에 투입될 수 있는 Cu film 수량에 관한 목적함수와 제약조건이 수식으로 구현되었다. 공식화된 수식은 D-Wave 양자 어닐러에 임베딩되기 위해 Ocean SDK(software development kit)와 Leap을 통해 프로그래밍 되었으며, 양자 어닐링 과정을 통해 두께 방향 열전도도가 최대를 만족하는 최적의 Cu film 배치 조합이 도출되었다. 도출된 배치 조합은 투입될 수 있는 Cu film의 수량이 적어질수록 단순한 배치 형태를 나타내었으며, 수량이 많아질수록 세밀한 배치를 보였다. Cu film의 배치 수량에 따라 생성된 최적 조합들은 두께 방향으로의 고유 열전도 경로를 나타내었으며, Cu film의 횡방향 배치 자유도가 두께 방향 열전도도 결과에 민감하게 나타날 수 있음을 보였다.

• 한국재료학회지
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• 제16권3호
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• pp.183-187
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• 2006

We present the effects of rapid thermal annealing (RTA) temperature on the structural and optical properties of self-assembled InAs quantum dot (QD) structures grown on GaAs substrates by molecular beam epitaxy (MBE). The photoluminescence (PL) measurements are performed in a closed-cycle refrigerator as a function of temperature for the unannealed and annealed samples. RTA at higher temperature results in the increase in island size, the corresponding decrease in the density of islands, and the redshift in the PL emission from the islands. The temperature dependence of the PL peak energy for the InAs QDs is well expressed by the Varshni equation. The thermal quenching activation energies for the samples unannealed and annealed at $600^{\circ}C$ are found to be $25{\pm}5meV$ and $47{\pm}5$ meV, respectively.

• ETRI Journal
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• 제46권3호
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• pp.367-378
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• 2024

We propose a number-theory-based quantized mathematical optimization scheme for various NP-hard and similar problems. Conventional global optimization schemes, such as simulated and quantum annealing, assume stochastic properties that require multiple attempts. Although our quantization-based optimization proposal also depends on stochastic features (i.e., the white-noise hypothesis), it provides a more reliable optimization performance. Our numerical analysis equates quantization-based optimization to quantum annealing, and its quantization property effectively provides global optimization by decreasing the measure of the level sets associated with the objective function. Consequently, the proposed combinatorial optimization method allows the removal of the acceptance probability used in conventional heuristic algorithms to provide a more effective optimization. Numerical experiments show that the proposed algorithm determines the global optimum in less operational time than conventional schemes.

• 한국광학회:학술대회논문집
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• 한국광학회 2009년도 동계학술발표회 논문집
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• pp.525-526
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• 2009

we investigated the effect of rapid thermal annealing (RTA) temperature on photoluminescence (PL) of 635 nm InGaP/InGaAlP multiple quantum well structure. RTA is performed with the quantum well structure with 5.5 nm of well width. The highest PL peak intensity is shown at 1 min. of RTA at $720^{\circ}C$ sample as 3 times higher as compared to the as-grown sample. The effect may be assigned to an expected reduction in number of nonradiative recombination centers in the quantum well.

• Journal of Magnetics
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• 제11권3호
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• pp.119-122
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• 2006

We electroplated copper-cobalt thin films on a silicon substrate, which had 150 nm thick copper seed layer. The adhesion between the two metallic layers could be increased by utilizing a proper organic additive, pulse plating technique, and high temperature annealing. The thin films exhibited columnar growth of the deposits and enhanced adhesion. This is attributed to the grain growth mechanism introduced by the additive and annealing.

• 한국진공학회:학술대회논문집
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• 한국진공학회 2007년도 제33회 하계학술대회 초록집
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• pp.286-286
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• 2007

• 한국전기전자재료학회논문지
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• 제13권6호
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• pp.467-471
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• 2000

The thermal annealing effect of $Zn_{0.9}Cd_{0.1}$ single quantum-well structures grown by molecular beam epitaxy is investigated. As the results of before and after rapid thermal annealed samples a red shift of E1-HH1 peak by Cd interdiffusion during thermal annealing of ZnCeSe/ZnSe sample was observed. In the case of annealed sample over $450^{\circ}C$ donor and acceptor impurities related peaks were observed which seems to be due to a diffusion of Ga and As from GaAs substrate. And also interdiffusion phenomena is idenified by the results of DCX measurements and which are consisten with the PL measurements.

• 한국진공학회:학술대회논문집
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• 한국진공학회 2010년도 제39회 하계학술대회 초록집
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• pp.207-207
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• 2010

Both ZnO and GaN have excellent physical properties in optoelectronic devices such as blue light emitting diode (LED), blue laser diode (LD), and ultra-violet (UV) detector. The ZnO/GaN heterostructure, which has a potential to achieve the cost efficient LED technology, has been fabricated by using radio frequency (RF) sputtering, pyrolysis, metal organic chemical vapor deposition (MOCVD), direct current (DC) arc plasmatron, and pulsed laser deposition (PLD) methods. Among them, the PLD system has a benefit to control the composition ratio of the grown film from the mixture target. A 500-nm-thick ZnO film was grown by PLD technique on c-plane GaN/sapphire substrates. The post annealing process was executed at some varied temperature between from $300^{\circ}C$ to $900^{\circ}C$. The morphology and crystal structural properties obtained by using atomic force microscope (AFM) and x-ray diffraction (XRD) showed that the crystal quality of ZnO thin films can be improved as increasing the annealing temperature. We will discuss the post-treatment effect on film quality (uniformity and reliability) of ZnO/GaN heterostructures.

• 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.