• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 2001년도 추계학술대회 논문집 Vol.14 No.1
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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.

• Imaging Science in Dentistry
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• 제31권2호
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• pp.85-91
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• 2001

Purpose: To evaluate the effect of the slice thickness and the size of region of interest (ROI) on CT number using quantitative CT phantom Materials and Methods: The phantom containing 150 mg/cc, 75 mg/cc and 0 mg/cc calcium hydroxyapatite was scanned with 1, 3, 5 and 10 mm slice thicknesses by single energy quantitative computed tomography (QCT). CT numbers were measured on center position of the phantom. Shape of ROI was circular and sizes were 1, 3, 5, 11, 16, 21, 26 and 33 mm². ANOVA and Tukey's multiple comparison method were performed for statistical comparison of CT numbers according to different slice thicknesses. Coefficient of variation of CT number measured in each size of ROI was evaluated in same slice thickness. Results : CT numbers had statistically significant difference according to slice thicknesses (p<0.05). As the slice thickness increased, CT number also increased. As the density of phantom became lower and the size of ROI became smaller, the coefficient of variation of CT number increased. When the size of ROI was more than 11 mm² in 1 mm slice thickness, 5 mm² in 3 mm slice thickness and 3 mm² in 5 mm slice thickness, the coefficient of variation became consistent. In 10 mm slice thickness, the size of ROI had little effect on the coefficient of variation. Conclusion: CT number had variation according to the slice thickness and the size of ROI although the object was homogeneous. The slice thickness and the size of ROI are critical factors in precision of the CT number measurements.

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 2001년도 추계학술대회 논문집
• /
• pp.181-184
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• 2001

Chemical Mechanical Polishing(CMP) of Shallow Trench Isolation(STI) 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.

• 한국식품저장유통학회지
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• 제7권1호
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• pp.44-50
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• 2000

Physicochemical properties and sensory evaluation of Satsuma mandarin produced in Cheju were investigated . Fruit index(width/Length), soluble solids and acid content of Citrus unshiu marc. var. miyagawa(miyagawa) and C. unshiu marc. var.(okitsu) harvested at 1st December were 1.16 and 1.23, 12.12 and 12.01, 0.97 and 1.09, respectively. and the fruit of miyagawa was showed somewhat round in shape, compared to ikitsu. the taste of miyagawa seemed to be better than okitsu. However, compared to miyagawa, peel thickness was thinner, flesh ratio was higher, and firmness was higher as 0.502kg-force in kitsu. Nevertheless there were some differences among panelist groups in sensory evaluation , middle size of citrus fruits were favorable to most panelists, but except very small or very large size of fruits, there were not so much differences in okitsu. The panelists referred to somewhat flat-shaped fruits from that sensory evaluation score was increased to 1.3 in fruit index. nevertheless there were not so much differences in full-colored fruits, the citrus peel color of reddish yellow was more favorable than greenish or pale yellow color. the score was increased more linearly according to citrusfruit produced in optimum ciltivation area, and was prefered to thinner in peel thickness , Correlation between soluble solids, acid content , Brix/acid ratio and flesh ratio with sensory evaluation score were not showed significantly, it was different to with citrus juice. This data obtained in this experiments are supposed to be applied to the quality evaluation of Satsuma mandarin produced in Cheju .

• Journal of Electrical Engineering and Technology
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• 제12권2호
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• pp.840-845
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• 2017

In this paper, in order to investigate the lifetime of oil-paper insulation, specimens were artificially aged with thermal and electrical multiple stresses. Accelerated ageing factors and equivalent operating years for each aging temperatures were derived from results of tensile strengths for the aged paper specimens. Also, the evaluation for the multi-stress aged specimens were carried out through the measurement of impulse breakdown voltage at high temperature of $85^{\circ}C$. The lifetimes of the oil-paper insulations were calculated with the value of 66.7 for 1.0 mm thickness specimens and 69.7 for 1.25 mm thickness specimens throughout the analysis of impulse BD voltages using equivalent operating years, which means that dielectric strengths would not be severely decreased until the mechanical lifetime limit. Therefore, for the lifetime evaluation of the oil-paper insulation, thermal aging would be considered as a dominant factor whereas electrical degradation would be less effective.

• Corrosion Science and Technology
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• 제14권1호
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• pp.33-39
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• 2015

Pipe wall-thinning by flow-accelerated corrosion and various types of erosion is significant damage in secondary system piping of nuclear power plants(NPPs). All NPPs in Korea have management programs to ensure pipe integrity from degradation mechanisms. Ultrasonic test(UT) is widely used for pipe wall thickness measurement. Numerous UT measurements have been performed during scheduled outages. Wall-thinning rates are determined conservatively according to several evaluation methods developed by Electric Power Research Institute(EPRI). The issue of reliability caused by measurement error should be considered in the process of evaluation. The reliability analysis method was developed for single and multiple measurement data in the previous researches. This paper describes the application results of reliability analysis method to real measurement data during scheduled outage and proved its benefits.

• 한국레이저가공학회지
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• 제2권1호
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• pp.61-67
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• 1999

This study introduces the new concept in the evaluation criteria of the $CO_2$ laser Tailored Blank weldability, The materials used are 0.7mm, 1.5mm thick low carbon automotive galvanized steels. Welding tests were conducted for both similar thickness(0.7mm-0.7mm, 1.5mm-1.5mm) and dissimilar thickness(0.7mm-1.5mm) cases. The criteria developed for optimum welding conditions were based on relationship between results of die press forming test, weld transverse tensile test Erichsen test and weld penetration measurements. Application of the developed criteria(fracture ratio, strength ratio and D/To) in obtaining optimum welding condition revealed that a weld which satisfied any of the criteria did not fracture during actual die press test.

• 한국자동차공학회논문집
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• 제5권2호
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• pp.87-93
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• 1997

The bonding strength evaluation of light weight materials for electrical vehicle applications has been performed through single lap joint tests in which the design parameters such as fillet, joint style, adherend, bonding overlap length,bonding thickness, and environmental condition(soaking time in $25^{\circ}C$ water) are considered. It is experimentally oberved that lap shear strength of joint increases for higher fillet height, longer overlap length, and thinner bonding layer thickness. Al-Al adherend combination shows much higher lap shear strength than AL-FRP and FRP-FRP adherend combinations. Riveting at adhesive bonded joint of AL-AL adherend combination makes lap shear strength decrease. Effect of soaking time on lap shear strength is negligible.

• 항공우주기술
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• 제12권1호
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• pp.81-86
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• 2013

본 연구에서는 다양한 발사체 추진기관 공급계 배관 자재 중 STS 300 계열의 금속보다 강도가 높고 용접성이 우수할 것이라고 판단되는 21-6-9 합금소재를 이용하여 산화제 주배관의 시편을 제작 하였다. 제작된 시편은 내압 시험을 수행하여 요구되는 내압 강도를 유지할 수 있는지를 확인하였다.

• 한국콘크리트학회:학술대회논문집
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• 한국콘크리트학회 2002년도 가을 학술발표회 논문집
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• pp.495-500
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• 2002

The purpose of this study is to develop and to apply this permanent cement mortar form as one of those system forms to improve existing form's problems. (1) In the fire proof test with combined specimen, the fire proof covering including form section thickness is satisfied with the fire proof criterion. It is considered that form section thickness has no problem (2) The suitable method of normal pressure steam curing for the form's mass production is 4 hours in 65℃ considering production cost, the silica fume admixture is economic.