• Transactions on Electrical and Electronic Materials
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• v.3 no.3
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• pp.14-17
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• 2002

The HDP (High Density Plasma) CVD process consists of a simultaneous sputter etch and chemical vapor deposition. As CMOS process continues to scale down to sub- quarter micron technology, HDP process has been widely used fur the gap-fill of small geometry metal spacing in inter-metal dielectric process. However, HBP CVD system has some potential problems including plasma-induced damage. Plasma-induced gate oxide damage has been an increasingly important issue for integrated circuit process technology. In this paper, thin gate oxide charge damage caused by HDP deposition of inter-metal dielectric was studied. Multiple step HDP deposition process was demonstrated in this work to prevent plasma-induced damage by introducing an in-situ top SiH$_4$ unbiased liner deposition before conventional deposition.

• Journal of Korean Library and Information Science Society
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• v.48 no.4
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• pp.235-258
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• 2017

The purpose of this study is to analyze research trends of archives management in Korea by comparing LDA (Latent Semantic Allocation) topic modeling, which is the most famous method in text mining, and HDP (Hierarchical Dirichlet Process) topic modeling, which is developed LDA topic modeling. Firstly we collected 1,027 articles related to archives management from 1997 to 2016 in two journals related with archives management and four journals related with library and information science in Korea and performed several preprocessing steps. And then we conducted LDA and HDP topic modelings. For a more in-depth comparison analysis, we utilized LDAvis as a topic modeling visualization tool. At the results, LDA topic modeling was influenced by frequently keywords in all topics, whereas, HDP topic modeling showed specific keywords to easily identify the characteristics of each topic.

• JSTS:Journal of Semiconductor Technology and Science
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• v.11 no.3
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• pp.135-145
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• 2011

Accurate process characterization and optimization are the first step for a successful advanced process control (APC), and they should be followed by continuous monitoring and control in order to run manufacturing processes most efficiently. In this paper, process characterization and recipe optimization methods with multiple outputs are presented in high density plasma-chemical vapor deposition (HDP-CVD) silicon dioxide deposition process. Five controllable process variables of Top $SiH_4$, Bottom $SiH_4$, $O_2$, Top RF Power, and Bottom RF Power, and two responses of interest, such as deposition rate and uniformity, are simultaneously considered employing both statistical response surface methodology (RSM) and neural networks (NNs) based genetic algorithm (GA). Statistically, two phases of experimental design was performed, and the established statistical models were optimized using performance index (PI). Artificial intelligently, NN process model with two outputs were established, and recipe synthesis was performed employing GA. Statistical RSM offers minimum numbers of experiment to build regression models and response surface models, but the analysis of the data need to satisfy underlying assumption and statistical data analysis capability. NN based-GA does not require any underlying assumption for data modeling; however, the selection of the input data for the model establishment is important for accurate model construction. Both statistical and artificial intelligent methods suggest competitive characterization and optimization results in HDP-CVD $SiO_2$ deposition process, and the NN based-GA method showed 26% uniformity improvement with 36% less $SiH_4$ gas usage yielding 20.8 ${\AA}/sec$ deposition rate.

• Nuclear Medicine and Molecular Imaging
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• v.43 no.6
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• pp.588-591
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• 2009

A 26-year-old man with renal cell carcinoma underwent $^{99m}Tc$-HDP bone scintigraphy for detecting bony metastasis after left total nephrectomy for renal cell carcinoma. $^{99m}Tc$-HDP bone scintigraphy showed small hot lesion in the first lumbar spine. About 12 months later, he underwent spinal MRI for lower back pain. A large mass was seen around spinous process of the first lumbar spine (L1) on spinal MRI and confirmed as metastatic renal cell carcinoma by bone biopsy. $^{99m}Tc$-HDP bone scintigraphy and $^{18}F$-FDG PET/CT were underwent for further evaluation. $^{99m}Tc$-HDP bone scintigraphy showed cold lesion in the first lumbar spine which was initially hot and newly developed hot lesion in the twelfth thoracic spine, and which were shown as hypermetabolic lesions in $^{18}F$-FDG PET/CT. We report a case of bony metastasis from renal cell carcinoma which is changed from hot lesion to cold lesion in $^{99m}Tc$-HDP bone scintigraphy and compare with $^{18}F$-FDG PET/CT.

• JSTS:Journal of Semiconductor Technology and Science
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• v.4 no.1
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• pp.45-51
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• 2004

We have proposed a new shallow trench isolation (STI) process using flowable oxide (F-oxide) chemical vapor deposition (CVD) for DRAM application and it was successfully developed. The combination of F-oxide CVD and HDP CVD is thought to be the superior STI gap-filling process for next generation DRAM fabrication because F-oxide not only improves STI gap-filling capability, but also the reduced local stress by F-oxide in narrow trenches leads to decrease in junction leakage and gate induced drain leakage (GIDL) current. Finally, this process increased data retention time of DRAM compared to HDP STI. However, a serious failure occurred by symphonizing its structural dependency of deposited thickness with poor resistance against HF chemicals. It could be suppressed by reducing the flow time during F-oxide deposition. It was investigated collectively in terms of device yield. In conclusion, the combination of F-oxide and HDP oxide is the very promising technology for STI gap filling process of sub-100nm DRAM technology.

• Journal of KIISE
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• v.44 no.10
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• pp.1026-1033
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• 2017

In this paper a Bayesian modeling and duration-based prediction method is proposed for health clinic time series data using the Hierarchical Dirichlet Process Hidden Markov Model (HDP-HMM). HDP-HMM is a Bayesian extension of HMM which can find the optimal number of health states, a number which is highly uncertain and even difficult to estimate under the context of health dynamics. Test results of HDP-HMM using simulated data and real health clinic data have shown interesting modeling behaviors and promising prediction performance over the span of up to five years. The future of health change is uncertain and its prediction is inherently difficult, but experimental results on health clinic data suggests that practical long-term prediction is possible and can be made useful if we present multiple hypotheses given dynamic contexts as defined by HMM states.

• Journal of the Institute of Electronics Engineers of Korea SD
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• v.39 no.1
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• pp.31-38
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• 2002

In order to improve the 0.35 $mutextrm{m}$-via hole etching process the etching characteristic of the gas $C_2F_{6}$ has been analyzed. The samples were triple-layer films(TEOS/SOG/TEOS) on 8-inch wafers and the orthogonal array matrix technique was used for the process. The equipment for etching was the transformer coupled plasma (TCP) source which is a type of high density plasma(HDP). This experiment showed the etching rate for $C_2F_{6}$ was 0.8 $mutextrm{m}$/min-1.1 $mutextrm{m}$/min and the measured uniformity was under $pm$6.9% in the matrix window. The CD skew comparison between pre and post-etching was under 10% which is an outstanding results in the window of profile in anisotropic etching. There was no problem in C2F6 with the flow rate of 20sccm, but when 14sccm of $C_2F_{6}$ was supplied there was a recess problem on the inner wall of SOG film. Consequently the etching characteristic of $C_2F_{6}$ shows a fast etching rate and a very wide process window in HDP TCP.

• Archives of design research
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• v.20 no.2 s.70
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• pp.65-76
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• 2007

The primary purpose of this study was to evolve integrated design process for Experiential Design which is based on the former study, 'The Influence of Cognitive Factors on the Creative Abilities in Design'. Experience is a transformation factor to all of the design processes, which has three phase of problem solving; Input, Process, and Output. We regard Experiential Design is a transforming process from concept to experience, and set up a mode) of Holistic Design Process (HDP), which consists of four domains: Four Causes, Thinking Modes, Sensory Modalities, and Creative Abilities. Revolving Sensory Modalities (SM), Creative Abilities (CA), and Thinking Modes (TM) around Product Design Specification (PDS) through a design process, Design Concepts ripen and mature into Externalization. Each component of Experiential Design (TM, SM, and CA) turns around the PDS. Here, experience is first perceived by the five senses. Then, the knowledge is formed, and the CA works for a problem solving. And TM controls all of these procedures. We regard these are a phenomenon of Experiential Design. The HDP can be helpful to develop valuable solutions and create a good experience.

• Proceedings of the Korean Institute of Surface Engineering Conference
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• 2006.10a
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• pp.2-3
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• 2006

본 논문에서는 신경망 모델링을 통하여 HDP-CVD를 이용한 실리콘 산화막 형성에 영향을 주는 다섯 가지 공정 장비 변수와 그에 따른 두 가지 출력 파라미터 Deposition rate과 Uniformity와의 관계를 동시에 고려한 특성결과를 분석하고， 최적의 recipe를 Genetic Algorithm을 통해 제시하였다. 실험계획법을 사용하여， 필요한 실험의 횟수를 최소화 하였으며 그 실험결과를 신경망 모델링을 통하여 입력변수와 출력파라미터의 관계를 3차원의 반응표면 곡선으로 분석하였다. 이 과정을 통해 Deposition rate과 Uniformity을 동시에 고려한 두 출력파라미터를 만족하는 최적의 입력변수 값들을 제시하였다.

• The Journal of the Korea institute of electronic communication sciences
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• v.5 no.1
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• pp.81-87
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• 2010

In this paper, we have fabricated $SiO_2$ oxidation thin films by HDP-CVD(high density plasma-chemical vapor deposition) method for passivation layer or barrier layer of OLED(organic light emitting diode). We have control and estimate the deposition rate and relative index characteristics with process parameters and get optimized conditions. They are gas flow rate($SiH_4:O_2$=30:60[sccm]), 70 [mm] distance from source to substrate and no-bias. The WVTR(water vapor transmission rate) is 2.2 [$g/m^2$_day]. Therefore fabricated thin film can not be applied as passivation layer or barrier layer of OLED.