• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 2008년도 하계학술대회 논문집 Vol.9
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• pp.538-538
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• 2008

금속계열의 박막을 평탄화하기위해서는 슬러리에 함유된 산화제에 의해 부동태층의 형성이 선행되어야 한다. 따라서 본 논문에서는 Copper 박막의 표면을 부동태층으로 형성시키고 CMP공정을 하기위해 산화제에 dipping을 시켰으며 삼화제의 종류는 $H_2O_2$, MSW2000B, $KIO_3$로 하고 dipping 시간은 30초, 60초, 90초, 3분, 10분으로 하여 시간과 산화제 종류에 따른 부동태층의 변화를 연구하였다. 부동태층의 관찰은 FESEM을 이용하여 표면과 단면을 관찰하였고 부동태층의 조성비율은 EDX를 이용하여 조사하였다. MSW 2000B의 경우는 부동태층이 덩어리 모양으로 형성되었으며 포화현상은 3분에 일어났다. 반면에 $H_2O_2$의 경우는 부동태층이 침상 모양으로 형성되었으며 포화현상은 90초에 일어났다. 산화제에 의해 부동태층을 형성시킨 후 POLI-450을 이용하여 평탄화공정을 진행하였으며 CMP공정조건은 부동태층의 연질상태임을 감안하여 헤드 스피드 20rpm, 플레이튼 스피드 10rpm, 슬러리 주입속도 90ml/min, 공정온도는 상온으로 하여 진행하였다. $H_2O_2$를 산화제로 사용하여 dipping을 하고 CMP를 하였을 경우에 균일한 박막을 확보 할 수 있었으며 CMP 공정 후 copper 박막의 균일성은 FESEM을 이용하여 관찰 하였다.

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 2008년도 하계학술대회 논문집 Vol.9
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• pp.543-543
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• 2008

반도체 집적회로의 제조 공정 중 CMP 공정이 필수 핵심기술이 되었다. 이처럼 CMP 공정 기술이 다층 배선 구조의 광역 평탄화를 위해서는 매우 효과적이지만 기계적인 연마패드와 화학적인 식각 작용을 하는 슬러리를 이용하여 연마가 진행되므로 공정 결함이 문제시되어 왔다. 그 중에서도, 소모자재의 비용이 CMP 공정비용의 70% 이상을 차지하는 제조단가가 높다는 단점이 있다. 특히 고가의 슬러리가 차지하는 비중이 40% 이상을 넘고 있어, 슬러리 원액의 소모량을 줄이기 위한 연구들이 현재 활발히 연구 중에 있다. 본 논문에서는 새로운 혼합 연마제 슬러리에 대한 CMP 특성을 통해 기존에 상용화된 슬러리의 CMP 특성과 비교 고찰하여 MAS의 우수성을 입증하고, 최적화된 공정기술 연구의 기반으로 활용하고자 실리카 슬러리에 $MnO_2$ 연마제를 혼합하여 연마특성을 비교분석하였고, AFM, EDX, XRD, TEM분석을 통해 그 가능성을 알아보았다.

• Journal of Electrical Engineering and information Science
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• 제2권5호
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• pp.65-71
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• 1997

We present heterojunction solar cells with a structure of metal/a-Si:H(n-i-p)/poly-Si(n-p)/metal for the terrestrial applications. This cell consists fo two component cells: a top n-i-p junction a-Si:Hi cell with wide-bandgap 1.8eV and a bottom n-p junction poly-Si cell with narrow-bandgap 1.1eV. The efficiency influencing factors of the solar cell were investigated in terms of simulation an experiment. Three main topics of the investigated study were the bottom cell with n-p junction poly-Si, the top a-Si:H cell with n-i-p junction, and the interface layer effects of heterojunction cell. The efficiency of bottom cell was improved with a pretreatment temperature of 900$^{\circ}C$, surface polishing, emitter thickness of 0.43$\mu\textrm{m}$, top Yb metal, and grid finger shading of 7% coverage. The process optimized cell showed a conversion efficiency about 16%. Top cell was grown by suing a photo-CVD system which gave an ion damage free and good p/i-a-Si:H layer interface. The heterojunction interface effect was examined with three different surface states; a chemical passivation, thermal oxide passivation, and Yb metal. the oxide passivated cell exhibited the higher photocurrent generation and better spectral response.

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 2001년도 추계학술대회 논문집
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• 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.

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 2001년도 추계학술대회 논문집
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• pp.171-175
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• 2001

Chemical mechanical polishing(CMP) process has been widely used to planarize dielectrics and metal, which can apply to employed in integrated circuits for sub-micron technology. Despite the increased use of CMP process, it is difficult to accomplish the global planarization of free-defects in inter level dielectrics and metal. Especially, defects like (micro-scratch) lead to severe circuit failure, and affects yield. Current conditioning method - bladder type, orbital pad motion - usually provides unsuitable pad profile during ex-situ conditioning near the end of pad life. Since much of the pad wear occurs by the mechanism of bladder tripe conditioning and its orbital motion without rotation, we need to implement new ex-situ conditioner which can prevent abnormal regional force on pad caused by bladder-type and also need to rotate the pad during conditioning. Another important study of ADPC is related to the orbital scratch of which source is assumed as diamond grit dropped from the strip during ex-situ conditioning. Scratch from diamond grit damaged wafer severely so usual1y scraped. Figure 1 shows the typical shape of scratch damaged from diamond. We suspected that intensive forces to the edge area of bladder type stripper accelerated the drop of Diamond grit during conditioning, so new designed Flat stripper was introduced.

• 한국표면공학회지
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• 제42권4호
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• pp.161-168
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• 2009

Effects of TiN/Ti multilayer coating on the Ti-30Ta-xZr alloy surface were studied by using various experiments. The Ti-30Ta containing Zr (5, 10 and 15 wt%) were melted 10 times to improve chemical homogeneity by using a vacuum furnace. And then samples were homogenized for 24 hrs at $1000^{\circ}C$. The specimens were prepared for TiN/Ti coating by cutting and polishing. The prepared specimens were coated with TiN/Ti multilayers by using DC magnetron sputtering method. The analyses of coated surface and coated layer were carried out by field emission scanning electron microscope(FE-SEM), EDX, and X-ray diffractometer(XRD). From the microstructure and XRD analysis of Ti-30Ta-xZr alloys, The equiaxed structure was changed to needle-like structure with increasing Zr content. And $\alpha$-peak and elastic modulus increased as Zr content increased. The $\alpha$ and $\beta$ phase predominantly were found in the specimen containing high Zr content. According to the analysis of TiN/Ti coating layer, the surface defects and structures of Ti-30Ta-xZr were covered with TiN/Ti coating layer and surface roughness decreased.

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 2003년도 춘계학술대회 논문집 센서 박막재료 반도체 세라믹
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• pp.166-169
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• 2003

In this study, we evaluated the characteristics by the addition of 3 different kinds of nonionic surfactant to improve the dispersion stability of slurries. Slurry stability is an issue in any industry in which settling of particles can result in poor performance. So we observed the variation of particle size and settling rate when the concentration and addition time of surfactant are changed. When the surfactant is added after milling process, the particle size and pH became low. It is supposed that the particle agglomeration was disturbed by adsorption of surfactant on alumina abrasive. The settling rate was relatively stable when nonionic surfactant is added about 0.1~1.0 wt%. When molecular weight(MW) is too small like Brij 35, it was appeared low effect on dispersion stability. Because it can't prevent coagulation and subsequent settling with too small MW. The proper quality of MW for slurry stability was presented about 500,000. Consequently, the addition of nonionic surfactant to alumina slurry has been shown to have very good effect on slurry stabilization. If we apply this results to copper CMP process, it is thought that we will be able to obtain better yield.

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 2007년도 추계학술대회 논문집
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• pp.527-527
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• 2007

CMP가 1980년 IBM에 의해 반도체 웨이퍼의 표면 연마를 위해 적용된 후, 많은 연구 개발의 노력으로 반도체 집적회로의 제조 공정에서 필수 핵심기술이 되었으나, 소모자재(연마패드, 탄성지지대, 슬러리, 패드 컨디셔너)의 비용이 CMP 공정 비용의 70% 이상을 차지하는 등 제조단가가 높다는 단점을 극복할 수가 없었다. 특히, 고가의 슬러리가 차지하는 비중이 40% 이상을 넘고 있어, 슬러리 원액의 소모량을 줄이기 위한 연구들이 현재 활발히 연구 중이다. 슬러리의 변수로는 연마입자의 종류 및 특성, 용액의 pH, 연마입자의 슬러리내 안정성 등이 있다. 슬러리내 연마입자는 연마량과 균일도 측면에서 밀접한 관계를 가지고 있다. 또한, 연마제의 영향에 따라 연마율의 차이 즉, CMP 특성의 변화를 보이고 있기 때문에 투입량 또한 최적화가 필요하다. 본 연구에서는 새로운 연마제의 특성을 알아보기 위해 탈이온수(de-ionized water; DIW)에 $CeO_2,\;MnO_2,\;ZrO_2$ 등을 첨가한 후 분산시간에 따른 연마 특성과 atomic force microscopy (AFM)분석을 통해 표면 거칠기를 비교 분석하였다. 그리고, 세 가지 종류의 연마제를 각각 1wt%, 3wt%, 5wt% 첨가하여 산화막에 대한 CMP 특성을 알아본 후, scanning electron microscopy (SEM) 측정과 입도 분석을 통해 그 가능성을 알아보았다.

• 한국산업융합학회 논문집
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• 제23권6_2호
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• pp.1051-1058
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• 2020

The chemical mechanical planarization (CMP) is a process of physically and chemically polishing the semiconductor substrate. The planarization quality of a substrate can be evaluated by the within wafer non-uniformity (WIWNU). In order to improve WIWNU, it is important to manage the pad profile. In this study, a device capable of non-contact measurement of the pad thickness profile was developed. From the measured pad profile, the profile of the pad surface and the groove was extracted using the envelope function, and the pad thickness profile was derived using the difference between each profile. Thickness profiles of various CMP pads were measured using the developed PMS and envelope function. In the case of IC series pads, regardless of the pad wear amount, the envelopes closely follow the pad surface and grooves, making it easy to calculate the pad thickness profile. In the case of the H80 series pad, the pad thickness profile was easy to derive because the pad with a small wear amount did not reveal deep pores on the pad surface. However, the pad with a large wear amount make errors in the lower envelope profile, because there are pores deeper than the grooves. By removing these deep pores through filtering, the pad flatness could be clearly confirmed. Through the developed PMS and the pad thickness profile calculation method using the envelope function, the pad life, the amount of wear and the pad flatness can be easily derived and used for various pad analysis.

• The Journal of Advanced Prosthodontics
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• 제13권1호
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• pp.1-11
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• 2021

PURPOSE. The study compared the color change, lightness, and translucency of hybrid resin ceramics exposed to toothbrush abrasion and surface treatment. MATERIALS AND METHODS. Four hybrid ceramics [Lava Ultimate (LU), Vita Enamic (EN), Shofu HC (SH), and Crystal Ultra (CU)] were compared with a glass-ceramic (Vita Mark II) control. One hundred and twenty specimen blocks were prepared using a precision saw machine. Specimens in each material were divided into four subgroups based on the surface treatment (polishing or staining) and a storage medium (water or citric acid). Simulated tooth brushing with a mixture of 100 RDA (radioactive abrasives) with 0.3 ml distilled water was used for 3650 cycles (7300 strokes) for each specimen. Measurements for the color change, lightness, and translucency were measured after toothbrushing using a spectrophotometer. Statistical analysis compared outcomes using paired t-test, ANOVA, and Tukey post hoc test. RESULTS. The maximum color change was identified in SH (stained acid) [1.44 (0.40)], whereas the lowest was identified in EN (polished water) [0.66 (0.16)] material. The maximum and minimum loss of surface translucency was observed in SH (polished water) [12.3 (0.52)] and EN (stained acid) [6.5 (0.55)] specimens, respectively. Lastly, loss of lightness was the highest in VM (polished acid) [69 (0.95)], whereas the lowest was observed in CU (stained water) [56.7 (0.86)]. CONCLUSION. The comparison presented a significant effect of toothbrush abrasion on translucency and lightness of the hybrid resin ceramics. Color change was not significantly influenced irrespective of the storage medium employed. Surface staining demonstrated the preservation and stability of color and optical properties under the influence of toothbrush abrasion and chemical trauma.