• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.14 no.3
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• pp.175-184
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• 2001

In this study, the improved throughput and stability in device fabrication could be obtained by applying CMP process to STi structue in 0.18 um semiconductor device. To employ the CMP process in STI structure, the Reverse Moat Process used to be added after STI Fill, as a result, the process became more complex and the defect were seriously increased than they had been,. Removal rate of each thin film in STI CMP was not uniform, so, the device must have been affected. That is, in case of excessive CMP, the damage on the active area was occurred, and in the case of insufficient CMP nitride remaining was happened on that area. Both of them deteriorated device characteristics. As a solution to these problems, the development of slurry having high removal rate and high oxide to nitride selectivity has been studied. The process using this slurry afford low defect levels, improved yield, and a simplified process flow. In this study, we evaluated the 'High Selectivity Slurry' to do a global planarization without reverse moat step, and also we evaluated EPD(Eend Point Detection) system with which 'in-situ end point detection' is possible.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2000.07a
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• pp.90-93
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• 2000

In this study, the rise throughput and the stability in fabrication of device can be obtained by applying of CMP process to STI structure in 0.18um semiconductor device. To employ in STI CMP, the reverse moat process has been added thus the process became complex and the defects were seriously increased. Removal rates of each thin films in STI CMP was not equal hence the devices must to be effected, that is, the damage was occured in the device dimension in the case of excessive CMP process and the nitride film was remained on the device dimension in the case of insufficient CMP process than these defects affect the device characteristics. To resolve these problems, the development of slurry for CMP with high removal rate and high selectivity between each thin films was studied then it can be prevent the reasons of many defects by reasons of many defects by simplification of process that directly apply CMP process to STI structure without the reverse moat pattern process.

• Korean Journal of Heritage: History & Science
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• v.39
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• pp.59-93
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• 2006

Wolseong in Gyeongju is a historic fortress site of Silla constructed under the reign of Pasanisageum that played politically and militarily important roles. The moat surrounding Wolseong had a function of protecting the fortress in wartimes but became a part of gardening in the unified Silla era. Lots of relics have been excavated from Wolseong moat since 1985. Among them a great number and kinds of convex roofing tiles are regarded as invaluable sources to show different aspects of Silla, from its earlier time through to the unified and on. Roofing tiles were widely used for national buildings such as royal palaces, temples and fortresses and even for other popular architecture and have been dug out a lot more than any other relics. Research on them, however, has been done poorly. Vigorous study is in progress with increasing number of roofing tiles coming from many recent excavations, though it has been limited to the studies on general genealogy of patterns and manufacture processes. Thus this essay seeks to find which are dongbeomwas, roofing tiles of a same mold, out of convex tiles with the pattern of a unilobed lotus flower dug out of Wolseong moat. It also attempts to identify dongbeomwas by examining detail characteristics of roofing tiles which have been confusingly termed as yusawa, similar roofing tiles, or donghyeongwa, roofing tiles of the same shape. The significance of identifying dongbeomwas could be emphasized by various facts resulting from researches on dongbeomwas; the ways to identify them correctly, their time sequence and their excavated sites. In conclusion, dongbeomwas were identified out of many kinds of convex tiles. If they were excavated from the same site, they share some common features. The sites where they were dug out also tell what changes were made with passage of time and what relations they had with neighboring Anapji. Since roofing tile molds haven't been found yet, the only way to identify dongbeomwas is to examine details of roofing tiles. Dongbeomwas excavated in Wolseong moat help to discuss the time of each district of it. Meanwhile it should be noted that the term 'dongbeomwa' be used only after exact examining.

• The Transactions of the Korean Institute of Electrical Engineers C
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• v.50 no.9
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• pp.438-443
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• 2001

In the shallow trench isolation(STI)-chemical mechanical polishing(CMP) process, the key issues are the optimized thickness control, within-wafer-non-uniformity, and the possible defects such as pad oxide damage and nitride residue. The defect like nitride residue and silicon (or pad oxide) damage after STI-CMP process were discussed to accomplish its optimum process condition. To understand its optimum process condition, overall STI related processes including reverse moat etch, trench etch, STI fill and STI-CMP were discussed. Consequently, we could conclude that law trench depth and high CMP thickness can cause nitride residue, and high trench depth and over-polishing can cause silicon damage.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2001.07a
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• pp.33-36
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• 2001

Chemical mechanical polishing(CMP) process has been widely used to planarize dielectric layers, which can be applied to the integrated circuits for deep sub-micron technology. The rise throughput and the stability in the device fabrication can be obtained by applying of CMP process to STI structure in 0.18$\mu\textrm{m}$ m semiconductor device. The reverse moat process has been added to employ in of each thin films in STI-CMP was not equal, hence the devices must to be effected, that is, the damage was occurred in the device area for the case of excessive CMP process and the nitride film was remained on the device area for the case of insufficient CMP process, and than, these defects affect the device characteristics. Also, we studied the High Selectivity Slurry(HSS) to perform global planarization without reverse moat step.

• Earthquakes and Structures
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• v.5 no.5
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• pp.499-526
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• 2013

Seismic isolation is an effective method for the protection of buildings and their contents during strong earthquakes. This research work aims to assess the appropriateness of the linear and nonlinear models that can be used in the analysis of typical low-rise base isolated steel buildings, taking into account the inherent nonlinearities of the isolation system as well as the potential nonlinearities of the superstructure in case of strong ground motions. The accuracy of the linearization of the isolator properties according to Eurocode 8 is evaluated comparatively with the corresponding response that can be obtained through the nonlinear hysteretic Bouc-Wen constitutive model. The suitability of the linearized model in the determination of the size of the required seismic gap is assessed, under various earthquake intensities, considering relevant methods that are provided by building codes. Furthermore, the validity of the common assumption of elastic behavior for the superstructure is explored and the alteration of the structural response due to the inelastic deformations of the superstructure as a consequence of potential collision to the restraining moat wall is studied. The usage of a nonlinear model for the isolation system is found to be necessary in order to achieve a sufficiently accurate assessment of the structural response and a reliable estimation of the required width of the provided seismic gap. Moreover, the simulations reveal that the superstructure's inelasticity should be taken into account, especially if the response of the structure under high magnitude earthquakes is investigated. The consideration of the inelasticity of the superstructure is also recommended in studies of structural collision of seismically isolated structures to the surrounding moat wall, since it affects the response.

• Korean Chemical Engineering Research
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• v.53 no.4
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• pp.472-477
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• 2015

This study presents modified microfluidic picoinjector combined Faraday moat with silver nanoparticle electrode to increase electrical efficiency and fabrication yield. We perform simple dropping procedure of silver nanoparticles near the picoinjection channel, which solve complicate fabrication process of electrode deposition onto the microfluidic picoinjector. Based on this approach, the microfluidic picoinjector can be reliably operated at 180 V while conventional Faraday moat usually have performed above 260 V. Thus, we can reduce the operation voltage and increase safety. Furthermore, the microfluidic picoinjector is able to precisely control injection volume from 7.5 pL to 27.5 pL. We believe that the microfluidic picoinjector will be useful platform for microchemical reaction, biological assay, drug screening, cell culture device, and toxicology.

• Earthquakes and Structures
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• v.20 no.3
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• pp.295-307
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• 2021

The gap provided between adjacent structures in the metropolitan cities is mostly narrow due to architectural and financial issues. Consequently, structural pounding occurs between adjacent structures during earthquakes. It causes damages, ranging from minor local to more severe ones, especially in the case of seismically isolated buildings, due to their higher displacements. However, due to the increased flexibility of isolated buildings, the problem could become more detrimental to such structures. The effect of the seismic pounding of moat walls on the response of buildings isolated by Triple Friction Pendulum Bearing (TFPB) is investigated in this paper. To this propose, two symmetric three-dimensional models, including single-story and five-story buildings, are modeled in Opensees. Nonlinear Time History Analyses (NTHA) are performed for seismic evaluation. Also, five different sizes with four different sets of friction coefficients are considered for base isolators to cover a whole range of base isolation systems with various geometry configurations and fundamental period. The results are investigated in terms of base shear, buildings' drift, and roof acceleration. Results indicated a profound effect of poundings against moat walls. In situations of potential pounding, in some cases, the influence of impact on seismic responses of multistory buildings was more remarkable.

• Journal of the Korea Society for Simulation
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• v.23 no.3
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• pp.27-32
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• 2014

In this paper, We are going to propose the novel structure with improved behavior than the conventional vertical structure for VLSI CMOS circuits. For this, the proposed structure is the moat shape for STI. We want to analysis the characteristics of simulations about the electron concentration distribution, oxide layer shape of hot electron stress, potential flux and electric field flux, electric field fo themal damage and current-voltage characteristics in devices. Physically based models are the ambient and stress bias conditions of TCAD tool. As a analysis results, shallow trench structure were trended to be electric functions of passive as device dimensions shrink. The electrical characteristics influence of proposed STI structures on the transistor applications become stronger the potential difference electric field and saturation threshold voltage, are decreased the stress effects of active region. The fabricated device of based on analysis results data were the almost same characteristics of simulation results data.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2001.11b
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• pp.181-184
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• 2001

Chemical Mechanical Polishing(CMP) of Shallow Trench Isolation(STD structure in 0.18 m semiconductor device fabrication is studied. CMP process is applied for the STI structure with and without reverse moat pattern and End Point Detection (EPD) method is tested. To optimize the transistor properties related metal 1 parameters. we studied the correlation between CMP thickness of STI using high selectivity slurry. DOE of gate etch recipe, and 1st metal DC values. Remaining thickness of STI CMP is proportional to the thickness of gate-etch process and this can affect to gate profile. As CMP thickness increased. the N-poly foot is deteriorated. and the P-Poly Noth is getting better. If CD (Critical Dimension) value is fixed at some point,, all IDSN/P values are in inverse proportional to CMP thickness by reason of so called Profile Effect. Weve found out this phenomenon in all around DOE conditions of Gate etch process and we also could understand that it would not have any correlation effects between VT and CMP thickness in the range of POE 120 sec conditions. As CMP thickness increased by $100\AA$. 3.2 $u\AA$ of IDSN is getting better in base 1 condition. In POE 50% condition. 1.7 $u\AA$ is improved. and 0.7 $u\AA$ is improved in step 2 condition. Wed like to set the control target of CD (critical dimension) in gate etch process which can affect Idsat, VT property versus STI topology decided by CMP thickness. We also would like to decide optimized thickness target of STI CMP throughout property comparison between conventional STI CMP with reverse moat process and newly introduced STI CMP using high selectivity slurry. And we studied the process conditions to reduce Gate Profile Skew of which source known as STI topology by evaluation of gate etch recipe versus STI CMP thickness.