• Proceedings of the Materials Research Society of Korea Conference
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• 2009.11a
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• pp.23.2-23.2
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• 2009

Atomic layer deposition (ALD)have been proven to be a very attractive technique for the fabrication of advanced gate dielectrics and DRAM insulators due to excellent conformality and precise control of film thickness and composition, However, one major disadvantages of ALD is its relatively low deposition rate (throughput) because the deposition rate is typically limited by the time required for purging process between the introduction of precursors. In order to improve its throughput, many efforts have been made by commercial companies, for example,the modification reactor and development of precursors. However, any promising solution has not reported to date. We developed a new concept ALD system(Lucida TM S200) with high-throughput. In this process, a continuous flow of ALD precursor and purging gas are simultaneously introduced from different locations in the ALD reactor. A cyclic ALD process is carried out by moving the wafer holder up and down. Therefore, the time required for ALD reaction cycle is determined by speed of the wafer holder and vapor pressure of precursors. We will present the operating principle of our system and results of deposition.

• Proceedings of the Korean Vacuum Society Conference
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• 2013.02a
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• pp.689-689
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• 2013

Atomic layer deposition (ALD)에 의한 알루미늄 산화 막(Al2O3)은 고효율 결정질 실리콘 태양전지를 위한 우수한 표면 패시베이션 특성을 제공한다. 알루미늄 산화막는 고정적인 음전하를 가지고 있기 때문에 p-형 실리콘 태양 전지 후면은 전계에 의한 우수한 패시베이션 효과를 형성한다. 그러나, ALD 방식으로 증착된 알루미늄 산화막은 매우 긴 공정 시간을 필요로 하기 때문에 기존의 실리콘 태양 전지 공정에 적용하기가 어렵다. 본 논문에서는 알루미늄 산화막 형성에서 공정 시간을 줄이기 위해 Plasma assisted atomic layer deposition (PA-ALD) 방식을 적용했다. PA-ALD 기술은 trimethylaluminum (TMA)과 O2를 사용하여 기판 표면에 알루미늄 산화막을 증착하는 것으로 ALD 방식과 유사하지만, O2 플라즈마를 사용함으로써 증착 속도를 향상시킬 수 있다. 이는 좋은 패시베이션 특성을 가지는 알루미늄 산화막을 실리콘 태양전지양산 공정에 적용할 수 있는 가능성을 제시한다. PA-ALD 방식에 의한 알루미늄 산화막의 패시베이션 특성을 최적화하기 위해서 증착 후 열처리 조건에 대한 연구도 수행하였다. 막증착률이 1.1${\AA}$/cycle인 Al2O3층의 두께 변화에 따른 특성을 최적화하기 위해 공정 온도를 $250^{\circ}C$ 고정하고, 열처리 온도와 시간을 가변하였으며 유효 반송자수명을 측정하여 알루미늄 산화막의 패시베이션 특성을 확인했다.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.29 no.7
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• pp.440-444
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• 2016

Titanium oxide ($TiO_2$) thin films were synthesized on polymer insulator and Si substrates by atomic layer deposition (ALD) method. The surface and electrical properties of $TiO_2$ films synthesized at various ALD cycle numbers were investigated. The synthesized $TiO_2$ films exhibited higher contact angle and smooth surface. The contact angle of $TiO_2$ films was increased with the increase of ALD-cycle number. Also, the rms surface roughness of films was slightly rough with the increase of ALD-cycle number. The leakage current on $TiO_2$ film surface synthesized at various conditions were uniformed, and the values were decreased with the increase of ALD-cycle number. In the results, the performance of $TiO_2$ films for self-cleaning critically depended on a number of ALD-cycle.

• Proceedings of the Korean Vacuum Society Conference
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• 2013.08a
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• pp.76.1-76.1
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• 2013

Atomic Layer Deposition (ALD) has remarkably developed in semiconductor and nano-structure applications since early 1990. Now, the advantages of ALD process are well-known as controlling atomic-level-thickness, manipulating atomic-level-composition control, and depositing impurity-free films uniformly. These unique properties may accelerate ALD related industries and applications in various functional thin film markets. On the other hand, one of big markets, Display industry, just starts to look at the potential to adopt ALD functional films in emerging display applications, such as transparent and flexible displays. Unlike conventional ALD process strategies (good quality films and stable precursors at high deposition processes), recently major display industries have suggested the following requirements: large area equipment, reasonable throughput, low temperature process, and cost-effective functional precursors. In this talk, it will be mentioned some demands of display industries for applying ALD processes and/or functional films, in terms of emerging display technologies. In fact, the AMOLED (active matrix organic light emitting diode) Television markets are just starting at early 2013. There are a few possibilities and needs to be developing for AMOLED, Flexible and transparent Display markets. Moreover, some basic results will be shown to specify ALD display applications, including transparent conduction oxide, oxide semiconductor, passivation and barrier films.

• Journal of the Korean Child Neurology Society
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• v.24 no.3
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• pp.71-83
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• 2016

X-linked adrenoleukodystrophy (X-ALD) is caused by mutations in the ATP binding cassette subfamily D member 1 (ABCD1), a gene that encodes peroxisomal membrane located on ABC half-transporter named adrenoleukodystrophy protein (ALDP). X-ALD is characterized by a highly variable clinical spectrum, including progressive cerebral type, adrenomyeloneuropathy, and addison-only phenotype. No genotype/phenotype correlation has been established. Thus, unidentified modifier genes and other co-factors are speculated to modulate the phenotypic variation and disease severity. Recent advanced sequencing methods and reprogramming technologies not only offer an affordable and applicable approach to investigate the pathophysiological mechanisms of adrenoleukodystrophy, but also provide means to develop therapy. A causal therapy of X-ALD is lacking. Lorenzo's oil therapy is recommended for asymptomatic boys, but the longest study found that the oil was not beneficial at all to symptomatic X-ALD patients. Hematopoietic stem cell therapy has a relevant chance of success when performed during this early stage of cerebral type X-ALD. Recently, it has been insisted that lentiviral-mediated gene therapy of hematopoietic stem cells can provide clinical benefits in X-ALD. This review describes current knowledge on the clinical presentation, pathogenesis, diagnosis and management of X- ALD.

• Journal of Powder Materials
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• v.26 no.3
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• pp.243-250
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• 2019

Atomic layer deposition (ALD) is widely used as a tool for the formation of near-atomically flat and uniform thin films in the semiconductor and display industries because of its excellent uniformity. Nowadays, ALD is being extensively used in diverse fields, such as energy and biology. By controlling the reactivity of the surface, either homogeneous or inhomogeneous coating on the shell of nanostructured powder can be accomplished by the ALD process. However, the ALD process on the powder largely depends on the displacement of powder in the reactor. Therefore, the technology for the fluidization of the powder is very important to redistribute its position during the ALD process. Herein, an overview of the three types of ALD reactors to agitate or fluidize the powder to improve the conformality of coating is presented. The principle of fluidization its advantages, examples, and limitations are addressed.

• Journal of the Microelectronics and Packaging Society
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• v.29 no.1
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• pp.61-66
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• 2022

This study is to increase the surface area and maximize the effect of the catalyst by coating a nanometersized metal catalyst material on the anode layer using atomic layer deposition (ALD) technology. ALD process is known to produce uniform films with well-controlled thickness at the atomic level on substrates. We measured the performance by coating metals (Ni) on Ni/YSZ, which is the most widely known anode material for solid oxide fuel cells. ALD coatings began to show a decrease in cell performance over 3 nm coatings.

• Journal of the Microelectronics and Packaging Society
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• v.15 no.3
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• pp.47-52
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• 2008

This investigation was performed in order to study the properties of deposition and layers by Silicon Dioxide, SiO2, as dielectric onto Via and Trench which have high Aspect Ratio (AR). Thus, in order to confirm these properties, three types of CVD, which were PECVD, PETEOS, and ALD, were selected. On the experiment each of the property sections was estimated that step overage of PECVD: <30%, PETEOS: 45%, ALD: 75% and the RSM of PECVD: 27.8 nm, PETEOS: 2.1 nm, ALD: <2.0 nm. As a result of this experiment for the property of electric film, ALD was valuated to be the most favorable outcome. However, ALD was valuated to have the least quality for the deposition rate. ALD deposition rate, $10\;\AA/min$ by $1\;\AA$/1cycle, was prominently lower than PETEOS, which had the deposition rate of $5000\;\AA$/min. Since electric film requires at least $1000\;\AA$ thicknesses, ALD was not suitable for the deposition rate. which is the most important component in a practical use. Therefore, in this particular study, PETEOS was evaluated to be the most suitable recipe.

• Proceedings of the Korean Vacuum Society Conference
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• 2013.08a
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• pp.320.1-320.1
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• 2013

We have investigated the effect of surface passivation for crystalline silicon solar cell using ozone-based atomic layer deposited (ALD) $Al_2O_3$. We examined passivation properties such as uniformity, carrier lifetime, thickness, negative fixed charge density at AlOx/Si interface, and reflectance. The influences of process temperature and heat treatment were investigated using microwave photoconductance decay (PCD). Ozone-based ALD $Al_2O_3$ film shows the best carrier lifetime at lower deposition temperature than $H_2O$-based ALD.

• Journal of The Korean Society of Inherited Metabolic disease
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• v.14 no.2
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• pp.195-199
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• 2014

The X-linked adrenoleukodystrophy (X-ALD) is a peroxisomal disease by defects of ABCD1 gene on chromosome Xq28 leading to accumulation of saturated very long chain fatty acids (VLCFA), progressive demyelination and adrenal insufficiency. A 4-year-old boy was visited hospital with the chief compliant of hyperpigmentation beginning at 2-years old. Serum adrenocorticotropic hormone (ACTH) and cortisol concentration were compatible with adrenal insufficiency. The elevated plasmatic concentration of VLCFA and genotype analysis with sequencing of ABCD1 gene established the diagnosis of X-ALD. Brain MRI showed no abnormal high signal intensity on the white matter. Steroid replacement was started with good response. He initiated Lorenzo's oil with restriction of VLCFA by reducing the intake of fatty foods. The author highlight the importance of suspecting of X-ALD in the etiology of primary adrenal insufficiency as the first sign of the disease.