• 한국전기전자재료학회논문지
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• 제13권10호
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• pp.812-816
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• 2000

It is very important to understand the correlation of between inter dielectric(ILD) CMP process and various facility factors supplied to equipment to equipment system. In this paper, the correlation between the various facility factors supplied to CMP equipment system and ILD-CMP process was studied. To prevent the partial over-polishing(edge hot-spot) generated in the wafer edge area during polishing, we analyze various facilities supplied at supply system. With facility shortage of D.I water(DIW) pressure, we introduced an adding purified $N_2$(P$N_2$)gas in polishing head cleaning station for increasing a cleaning effect. DIW pressure and P$N_2$gas factors were not related with removal rate, but edge hot-spot of patterned wafer had a serious relation. We estimated two factors (DIW pressure and P$N_2$gas) for the improvement of CMP process. Especially, we obtained a uniform planarity in patterned wafer and prohibited more than 90% wafer edge over-polishing. In this study, we acknowledged that facility factors supplied to equipment system played an important role in ILD-CMP process.

• KSII Transactions on Internet and Information Systems (TIIS)
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• 제13권2호
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• pp.536-564
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• 2019

Soft faults are inherent in wireless sensor networks (WSNs) due to external and internal errors. The failure of processes in a protocol stack are caused by errors on various layers. In this work, impact of errors and channel misbehavior on process execution is investigated to provide an error classification mechanism. Considering implementation of WSN protocol stack, inter-process correlations of stacked and peer layer processes are modeled. The proposed model is realized through local and global decision trees for fault diagnosis. A hybrid framework is proposed to implement local decision tree on sensor nodes and global decision tree on diagnostic cluster head. Local decision tree is employed to diagnose critical failures due to errors in stacked processes at node level. Global decision tree, diagnoses critical failures due to errors in peer layer processes at network level. The proposed model has been analyzed using fault tree analysis. The framework implementation has been done in Castalia. Simulation results validate the inter-process correlation model-based fault diagnosis. The hybrid framework distributes processing load on sensor nodes and diagnostic cluster head in a decentralized way, reducing communication overhead.

• 대한전자공학회:학술대회논문집
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• 대한전자공학회 2005년도 추계종합학술대회
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• pp.615-618
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• 2005

In this work, the effects of corner transistors in SOI MOSFETs were investigated. We fabricated SOI MOSFETs with various widths and a fixed length and characterized them. The SOI thickness was $4000{\AA}$ and the buried oxide(BOX) thickness was $4000{\AA}$. The isolation of active region was simply done by silicon etching and TEOS sidewall formation. Several undesirable characteristics have been reported for LOCOS isolation in fabrication on SOI wafers so far. Although we used an STI-like process instead of LOCOS, there were still a couple of abnormal phenomena such as kinks and double humps in drain current. Above all, we investigated the location of the parasitic transistors and found that they were at the corners of the SOI in width direction by high-resolution SEM inspection. It turned out that their characteristics are strongly dependent on the channel width. We made a contact pad through which we can control the body potential and figured out the dependency of operation on the body potential. The double humps became more prominent as the body bias went more negative until the full depletion of the channel where the threshold voltage shift did not occur any more. Through these works, we could get insights on the process that can reduce the effects of corner transistors in SOI MOSFETs, and several possible solutions are suggested at the end.

• JSTS:Journal of Semiconductor Technology and Science
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• 제14권4호
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• pp.484-494
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• 2014

We describe a digitally controlled oscillator (DCO) which compensates the frequency variations for process, voltage, and temperature (PVT) variations with an accuracy of ${\pm}2.6%$ at 2.5 GHz. The DCO includes an 8 phase current-controlled ring oscillator, a digitally controlled current source (DCCS), a process and temperature (PT)-counteracting voltage regulator, and a bias current generator. The DCO operates at a center frequency of 2.5 GHz with a wide tuning range of 2.2 GHz to 3.0 GHz. At 2.8 GHz, the DCO achieves a phase noise of -112 dBc/Hz at 10 MHz offset. When it is implemented in an all-digital phase-locked loop (ADPLL), the ADPLL exhibits an RMS jitter of 8.9 ps and a peak to peak jitter of 77.5 ps. The proposed DCO and ADPLL are fabricated in 65 nm CMOS technology with supply voltages of 2.5 V and 1.0 V, respectively.

• 한국가스학회지
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• 제13권6호
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• pp.44-48
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• 2009

본 연구에서는 천연가스 액화 플랜트 산업에서의 핵심 기술인 액화공정 개발을 위해 두 가지 2단 압축 방식의 액화 사이클의 성능을 시뮬레이션 하였다. Process1은 케스케이드 액화공정을 기초로 하여 프로판, 에틸렌, 메탄 사이클 모두 인터쿨러가 적용된 것이다. Process 2는 위의 공정에 메탄과 에틸렌 사이클 사이에 액-가스 열교환기를 적용하였고, Process 3은 위의 공정에 에틸렌과 프로판 사이클 사이에 액-가스 열교환기를 추가로 적용하였으며, 인터쿨러를 적용한 케스케이드 공정과 성능을 비교하였다. Process 2의 COP는 Process 1보다 14.0%정도 높게 나타났고, LNG 단위 생산량 당 소비 동력은 11.5% 정도 낮게 나타났다.

• 한국경영과학회:학술대회논문집
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• 대한산업공학회/한국경영과학회 1992년도 춘계공동학술대회 발표논문 및 초록집; 울산대학교, 울산; 01월 02일 May 1992
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• pp.29-38
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• 1992

무인화된 대량생산 체제에서는 transfer line을 이용하게되며, cycle time의 단축을 위하여 측정 및 검사기능이 별도의 station으로 있어 가공후에 부품의 불량여부를 감지한다. 그러나 다품종소량생산체제에서는 FMC 또는 FMS가 적합하며, 이 시스템에 바람직한 감시기능으로서는 기내측정(inter-process)방식을 많이 이용한다. 여기서는 CNC선반과 머시닝센터에 접촉식 센서인 터치프로브(touch probe)를 설치하여 개발한 무인 FMC용 인터프로세스 3차원 측정 및 검사시스템을 소개한다.

• 산업경영시스템학회지
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• 제17권32호
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• pp.145-154
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• 1994

In this paper, monitoring processor in a circuit switched network is considered. Monitoring processor monitors communication links, and offers a grade of service in each link to controller. Such an information is useful for an effective maintenance of system. Two links with nonsymmetric system Parameters are considered. each link is assumed independent M/M/1/1 type. The Markov process is introduced to compute busy and idle portions of monitoring processor and monitored rate of each link. Inter-idle times and inter-monitoring times of monitoring processor between two links are respectively computed. A recursive formula is introduced to make computational procedure rigorous.

• Journal of the Korean Data and Information Science Society
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• 제17권1호
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• pp.195-204
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• 2006

In this paper, we consider a renewal process in which both the inter-arrival times and rewards are fuzzy random variables. We prove the uniform levelwise convergence of fuzzy renewal and fuzzy renewal rewards. These results improve the result of Popova and Wu[European J. Oper. Research 117(1999), 606-617] and the main result of Hwang [Fuzzy Sets and Systems 116 (2000), 237-244].

• 경영과학
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• 제27권3호
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• pp.87-98
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• 2010

In this paper, we drew upon IMP group's Interaction model to investigate the contributing impact of Inter-organizational system (IOS) on performance through enhancing inter-organizational relationship. While most extant literature studied the contribution of IOS from transaction efficiency perspective, the relational aspect of IOS contribution on the supply chain was addressed only by a few researches. As such, we intended to fill this gap of the IOS research stream. The conceptual model was developed, with reference to process theory, to analyze how the relational perspective could be applicable to IOS impact on performance. With the 129 sample data collected at the firm level,structural equation model using the LISREL was employed to validate the proposed research model. The empirical results supported the hypotheses such as the extent of IOS usage positively influences the interaction between the firms, which thereby enhances the extent of inter-firm partnership and performance. The results help better understanding the strategic use of IOS from relationship perspective.

• 한국정보디스플레이학회:학술대회논문집
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• 한국정보디스플레이학회 2003년도 International Meeting on Information Display
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• pp.15-18
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• 2003

Pentacene OTFTs of $Al_2O_3$ insulator treated with a diluted PMMA were fabricated for the application of the low voltage operation and large area displays. The operation voltage of 15 V and the mobility of 0.35 $cm^2/Vsec$ are obtained even adopting the thick dielectric of 100 nm which was deposited by atomic layer deposition at the temperature of $150^{\circ}C$. The current on-off ratio was $4.1{\times}10^4$ for the OTFTs treated with 9:1 PMMA and good saturation characteristics were obtained as drain voltage increases.