• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 2003년도 제5회 영호남 학술대회 논문집
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• pp.12-14
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• 2003

As the integrated circuit device shrinks to the smaller dimension, the chemical mechanical polishing (CMP). process was required for the global planarization of inter-metal dielectric (IMD) layer with free-defect. However, as the IMD layer gets thinner, micro-scratches are becoming as major defects. Micro-scratches are generated by agglomerated slurry, solidified and attached slurry in pipe line of slurry supply system. It is well known that the presence of hard and larger size particles in the CMP slurries increases the defect density and surface roughness of the polished wafers. In this paper, we have studied. aging effect the of CMP slurry as a function of particle size. We prepared and compared the self-developed silica slurry by adding of abrasives before and after annealing. As our preliminary experiment results, we could be obtained the relatively stable slurry characteristics comparable to original silica slurry in the slurry aging effect.

• 한국철도학회:학술대회논문집
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• 한국철도학회 2009년도 춘계학술대회 논문집
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• pp.1542-1549
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• 2009

The function of subgrade in the railway is to support track load on the subgrade as well as train load. Unlike the traditional railway, the uppermost subgrade layer in the Gyeongbu high speed railway was constructed as the reinforced road bed. The reinforced road bed comprises sub-ballast in the upper part and grade ballast in the lower part. The filling material such as soil and rocks in the subgrade can be settled by consolidation of original ground, compression due to self weight, plastic displacement due to train operation, and unequal settlement due to embankment material or improper compaction, therefore many efforts have been given for sufficient compaction and use of proper filling materials in the construction stage. The purpose of this study is to investigate the deformation state of subgrade in the Gyeongbu high speed railway. The investigation on the subgrade settlement was performed by choosing representative sections suspected to be settled based on the previous GPR test results and track maintenance history, measuring the settlement for some time period after installing settlement measuring instruments on and under the reinforced road bed. and analyzing the long-term subgrade settlement data from monitoring system which was installed at the construction stage of the high speed railway.

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 1999년도 춘계학술대회 논문집
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• pp.53-56
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• 1999

The weight decreases of the thermal deteriorated IV were rapidly increased at 80$0^{\circ}C$ and over. At the results of the analysis of the metallurgical microscope photographs. the surface of the thermal deteriorated IV at 30$0^{\circ}C$ was mixed with the elongated and original structures of Cu. But the elongated structures could not detected at 90$0^{\circ}C$ and over. The surface structures of SEM were detected a lot of small rounded particles between crystallizations. The EDX spectra of the thermal deteriorated IV at 3$0^{\circ}C$ were uniformly detected CuL, CuK, OK, and CIK, regardless of the scanning length, but the spectra of CIK could not found at 90$0^{\circ}C$. At the DTA curves, the endothermic reactions were occurred at about 25$0^{\circ}C$ to 30$0^{\circ}C$ and 43$0^{\circ}C$, and the exothermic reactions were occurred at about 48$0^{\circ}C$ respectively.

• 한국전기전자재료학회논문지
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• 제16권9호
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• pp.759-764
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• 2003

Recently, CMP (chemical mechanical polishing) technology has been widely used for global planarization of multi-level interconnection for ULSI applications. However, COO (cost of ownership) and COC (cost of consumables) were relatively increased because of expensive slurry. In this paper, we have studied the possibility of recycle of roused silica slurry in order to reduce the costs of CMP slurry. The post-CMP thickness and within-wafer non-uniformity (WIWNU) wore measured as a function of different slurry composition. As an experimental result, the performance of reused slurry with annealed silica abrasive of 2 wt％ contents was showed high removal rate and low non-uniformity. Therefore, we propose two-step CMP process as follows , In tile first-step CMP, we can polish the thick and rough film surface using remaked slurry, and then, in the second-step CMP, we can polish the thin film and fine pattern using original slurry. In summary, we can expect the saying of high costs of slurry.

• 한국전기전자재료학회논문지
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• 제17권2호
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• pp.138-143
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• 2004

CMP (Chemical Mechanical Polishing) technology for global planarization of multilevel interconnection structure has been widely studied for the next generation devices. Among the consumables for CMP process, especially, slurry and their chemical compositions play a very important role in the removal rates and within-wafer non-uniformity (WIWNU) for global planarization ability of CMP process. However, CMP slurries contain abrasive particles exceeding 1 ${\mu}{\textrm}{m}$ size, which can cause micro-scratch on the wafer surface after CMP process. Such a large size particle in these slurries may be caused by particle agglomeration in slurry supply-line. In this work, to investigate the effects of agglomeration on the performance of oxide CMP slurry, we have studied an aging effect of silica slurry as a function of particle size distribution and aging time during one month. We Prepared and compared the self-developed silica slurry by adding of alumina powders. Also, we have investigated the oxide CMP characteristics. As an experimental result, we could be obtained the relatively stable slurry characteristics comparable to aging effect of original silica slurry. Consequently, we can expect the saving of high-cost slurry.

• KSBB Journal
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• 제17권1호
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• pp.54-58
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• 2002

소수성 결합을 가지는 커들란 겔의 특성을 이용하여 지용성물질을 포함한 겔을 제조할 수 있었고, 지용성물질의 종류에 따라 건조시킨 겔 속에 상당한 양이 포함되는데, DHA는 건조중량의 90%가지 포함될 수 있었다. 또한, $\beta$-CD의 포접특성을 이용하여 DHA를 포함시킬 때 포접체 형성에 대한 물과 에탄올의 영향을 살펴본 결과 물 2.0 mL과 에탄올 0.5 mL이 DHA 포접에 효과적이었다. FT-IR과 XRD로 포접체를 분석해 본 결과 DHA를 포함한 포접체가 형성되었고, SEM을 통하여 포접체와 커들란, 플루란을 이용하여 마이크로 캡슐의 형태를 살펴볼 수 있었다.

• International Journal of Railway
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• 제1권3호
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• pp.113-116
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• 2008

The long-tenn exposure of polymeric composite materials to extreme-use environments, such as pressure, temperature, moisture, and load cycles, results in changes in the original properties of the material. In this study, the effect of combined environmental factors such as ultraviolet ray, high temperature and high moisture on mechanical and thermal analysis properties of glass fabric and phenolic composites are evaluated through a 2.5 KW accelerated environmental aging tester. The environmental factors such as temperature, moisture and ultraviolet ray applied of specimens. A xenon-arc lamp is utilized for ultraviolet light and exposure time of up to 3000 hours are applied. Several types of specimens - tensile, bending, and shear specimens that are warp direction and fill direction are used to investigate the effects of environmental factors on mechanical properties of the composites. Mechanical degradations for tensile, bending and shear properties are evaluated through a Universal Testing Machine (UTM). Also, storage shear modulus, loss shear modulus and tan a are measured as a function of exposure time through a Dynamic Mechanical Analyzer (DMA). From the experimental results, changes in material properties of glass fabric and phenolic composites are shown to be slightly degraded due to combined environmental effects.

• 한국지반공학회:학술대회논문집
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• 한국지반공학회 2010년도 추계 학술발표회 3차
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• pp.55-60
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• 2010

Rockfill zones in CFRD consist typically of large granular materials, usually the maximum particle size up to several meters, which makes laboratory testing to determine the mechanical properties of rockfill difficult. Commonly, the design strength of the rockfills is obtained by scaling down the original rockfill materials and performing laboratory strength tests for the reduced size materials. The objective of the present study is to investigate the effect of particle size on the shear behavior and the strength for granular materials. A series of large-scale triaxial tests was conducted on large granular materials with the maximum particle size varying from 20 to 50mm. The test results showed that overall shear behaviors were similar between the samples with different particle sizes while there were slight differences in the magnitudes of the peak shear stress between the samples. In addition, a simulation of the granular material with the max. particle size of 20mm was performed using DEM code, $PFC^{2D}$, and compared with the test results. The deviatoric stress versus strain behaviors of experimental and numerical tests were found to be matched well up to the peak stress state.

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 2000년도 하계학술대회 논문집
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• pp.99-102
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• 2000

Via for achieving reliable fabrication of MCM-D substrate was formed on the photosensitive BCB layer. MCM-D substrate consists of photosensitive BCB(Benzocyclobutene) interlayer dielectric and copper conductors. In order to form the vias in photosensitive BCB layer, the process of BCB and plasme etch using $C_2$F$_{6}$ gas were evaluated. The thickness of BCB after soft bake was shrunk down to 60% of the original. AES analysis was done on two vias, one is etched in $C_2$F$_{6}$ gas and the other is non etched. On via etched in $C_2$F$_{6}$, native C was detected and the amount of native C was reduced after Ar sputter. On via non etched in $C_2$F$_{6}$, organic C was detected and amount of organic C was reduced a little after Ar sputter. As a result of AES, BCB residue was not removed by Ar sputter, so plasma etch is necessary for achieving reliable via.ble via.

• 한국지반환경공학회 논문집
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• 제2권1호
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• pp.5-13
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• 2001

본 논문의 목적은 율촌 복합화력발전소 부지에 대한 지지력 산정 및 지반 특성 파악을 위한 공내재하시험의 결과를 분석하는 것이다. 율촌 복합화력발전소 부지는 인근의 야산 토취장에서 매립토를 채취 운반하여 강제치환공법으로 성토하였으며, 지질은 상부로부터 산토, 준설매립해성점토, 실트집모래, 원지반해성점토층, 풍화대, 풍화암, 연암의 순으로 존재한다. 공내재하시험은 해성점성토층을 제외한 토층에 대하여 토층의 특성에 따라 각각 다른 크기의 Probe와 Membrane을 사용하여 수행하였으며, 콘시험과의 상관성, 내부 마찰각과의 관계 및 토질 특성을 파악하였다.