• 한국윤활학회:학술대회논문집
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• 한국윤활학회 2002년도 제35회 춘계학술대회
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• pp.272-278
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• 2002

Recently, STI(Shallow Trench Isolation) process has attracted attention for high density of semiconductor device as a essential isolation technology. In this paper, the effect of pattern density, trench width and selectivity of slurry on dishing in STI CMP process was investigated by using specially designed isolation pattern. As trench width increased, the dishing tends to increase. At $20{\mu}m$ pattern size, the dishing was decreased with increasing pattern density Low selectivity slurry shows less dishing at over $160{\mu}m$ trench width, whereas high selectivity slurry shows less dishing at below $160{\mu}m$ trench width.

• 한국전기전자재료학회논문지
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• 제18권4호
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• pp.321-326
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• 2005

Chemical mechanical polishing(CMP) process is essential technology to be applied to manufacturing the dielectric layer and metal line in semiconductor devices. It has been known that overpolishing in CMP depends on pattern selectivity as a function of density and pitch, and use of fixed abrasive pad(FAP) is one method which can improve the pattern selectivity. Thus, dishing & erosion defects can be reduced. This paper introduces the manufacturing technique of FAP using hydrophilic polymers with swelling characteristic in water and explains the self-conditioning phenomenon. When applied to tungsten blanket wafers, the FAP resulted in appropriate performance in point of uniformity, material selectivity and roughness. Especially, reduced dishing and erosion was observed in CMP of tungsten pattern wafer with the proposed FAP.

• 센서학회지
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• 제20권6호
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• pp.428-433
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• 2011

We report on the building of a micro sensor array based on typical semiconductor fabrication processes aimed at monitoring selectively a specific gas in ambient of other gases. Chemical sensors can be applied for an electronic nose and/or robots using this technique. Microsensor array was fabricated on the same chip using 0.6${\mu}m$ CMOS technology, and unique gas sensing patterns were obtained by principal component analysis from the array. $SnO_2$/Pt sensor for CO gas showed a high selectivity to buthane gas and humidity. $SnO_2$ sensor for hydrogen gas, however, showed a low selectivity to CO and buthane gas. We can obtain more distinguishable patterns that provide the small sensing deviation(the high seletivity) toward a given analyte in the response space than in the chemical space through the specific parameterization of raw data for chemical image formation.

• 대한전자공학회:학술대회논문집
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• 대한전자공학회 1998년도 하계종합학술대회논문집
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• pp.465-468
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• 1998

For porous silicon layer to be used as active layer in various devices, it is necessary to be formed locally along with a designed pattern on the wafer. However, there is still no suitable masking layer to withstand against the high concentration of HF for a time of some minutes up to some hours during the anodic process effectively. In this work, we investigated the property of selectivity between p$^{+}$ and n layers to form localized porous silicon even without a mask by the difference of the anodic I-V characteristics on the doping level and doping type. The width of the pattern made in the sample was 2mm, and the formed porous silicon layer was observed by SEM to see the morphology on the cross section below the surface. As the results, it was found that the selectivity was reasonable for the pattern size over 100.mu.m.m.

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 2000년도 춘계학술대회 논문집 전자세라믹스 센서 및 박막재료 반도체재료 일렉트렛트 및 응용기술
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• pp.35-38
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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.l8um semiconductor device. Through reverse moat pattern process, reduced moat density at high moat density, STI CMP process with low selectivity could be to fit polish uniformity between low moat density and high moat density. Because this reason, in-situ motor current end point detection method is not fit to the current EPD technology with the reverse moat pattern. But we use HSS without reverse moat pattern on STI CMP and take end point current sensing signal.[1] To analyze sensing signal and test extracted signal, we can to adjust wafer difference within $110{\AA}$.

• 한국세라믹학회지
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• 제40권11호
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• pp.1073-1077
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• 2003

Sn $O_2$ 가스센서는 낮은 농도의 가연성 가스 및 유독 가스를 표면 저항의 변화로부터 탐지할 수 있으나, 가스 선택성이 부족하다는 단점을 가지고 있다. 이러한 단점을 보완하기 위해서는 가스반응기구의 규명과 같은 기초이론 연구와 함께 선택성이 우수한 센서재료의 개발 및 적절한 신호처리방법의 적용이 필요하다. 본 논문에서는 Sn $O_2$ 표면에서 일어나는 에탄올 (C$_2$ $H_{5}$OH)과 아세토니트릴($CH_3$CN)의 촉매산화반응을 가스크로마토그래피 분석을 통해 확인하였다. PdCl$_2$가 첨가된 Sn $O_2$ 센서는 에탄올과 아세토니트릴에 대하여 높은 감도를 보였고, 반면에 La$_2$ $O_3$가 첨가된 Sn $O_2$ 센서는 에탄올에 대해서는 높은 감도를, 그리고 아세토니트릴에 대해서는 낮은 감도를 보였다. 이들 두 센서재료 개발 및 패턴인식기법적용을 통하여 아세토니트릴에 대한 선택성을 크게 증가시킬 수 있었다. 아세토니트릴에 대한 최소 탐지농도는, 공기 중에서는 15 ppm이었고, 다른 방해가스와 함께 존재할 경우에는 20 ppm에서 100 ppm 정도로 나타났다.

• Archives of Pharmacal Research
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• 제21권4호
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• pp.385-390
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• 1998

Adozelesin and carzelesin are synthetic analogues of the extremely potent antitumor antibiotic CC-1065, which alkylates N3 of adenine in a consensus sequence $5^1$-(A/T)(A/T)$A^*$ ($A^*$ is the site of alkylation). We have investigated the DNA sequence selectivity of adozelesin and carzelesin by thermally ind ced DNA strand cleavage assay using radiolabeled restriction DNA fragments. An analysis of alkylation patterns shows that the consensus sequences for carzelesin and adozelesin have been found to be $5^1$-(A/T)(A/T)$A^*$ and $5^1$-(A/F)(G/C)(A/T)$A^*$. A new consensus sequence, $5^1$-(A/T)(A/T)$CA^*$, has been observed to display an additional alkylation site for adozelesin but not for carzelesin. These results indicate that the pattern of sequence selectivity induced by carzelesin is similar but not identical to those induced by adozelosin.

• 한국기계가공학회지
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• 제2권4호
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• pp.17-24
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• 2003

Chemical mechanical polishing(CMP) has been applied for planarization of topography after patterning process in semiconductor fabrication process. Tungsten CMP is necessary to build up interconnects of semiconductor device. But the tungsten dishing and the oxide erosion defects appear at end-point during tungsten CMP. It has been known that the generation of dishing and erosion is based on the over-polishing time, which is determined by pattern selectivity. Fixed abrasive pad takes advantage of decreasing the defects resulting flam reducing pattern selectivity because of the lower abrasive concentration. The manufacturing technique of fixed abrasive pad using hydrophilic polymers is introduced in this paper. For application to tungsten CMP, chemicals composed of oxidizer, catalyst, and acid were developed. In comparison of the general pad and slurry for tungsten CMP, the fixed abrasive pad and the chemicals resulted in appropriate performance in point of removal rate, uniformity, material selectivity and roughness.

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 2004년도 추계학술대회 논문집 Vol.17
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• pp.140-143
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• 2004

Chemical mechanical polishing(CMP) is essential technology to secure the depth of focus through the global planarization of wafer. But a variety of defects such as contamination, scratch, dishing, erosion and corrosion are occurred during CMP. Especially, dishing and erosion defects increase the resistance because they decrease the interconnect section area, and ultimately reduce the life time of the semiconductor. Due to this dishing and erosion must be prohibited. The pattern density and size in chip have a significant influence on dishing and erosion occurred over-polishing. Decreasing of abrasive concentration results in advanced pattern selectivity which can lead the uniform removal in chip and decrease of over-polishing. The fixed abrasive pad was applied and tested to reduce dishing and erosion in this paper. Consequently, reduced dishing and erosion was observed in CMP of tungsten pattern wafer with proposed fixed abrasive pad and chemicals.

• 한국정밀공학회지
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• 제22권2호
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• pp.38-45
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• 2005

Chemical mechanical polishing(CMP) has been widely accepted for the planarization of multi-layer structures in semiconductor fabrication. But a variety of defects such as abrasive contamination, scratch, dishing, erosion and corrosion are occurred during CMP. Especially, dishing and erosion defects increase the metal resistance because they decrease the interconnect section area, and ultimately reduce the lift time of the semiconductor. Due to this reason dishing and erosion must be prohibited. The pattern density and size in chip have a significant influence on dishing and erosion occurred by over-polishing. The fixed abrasive pad(FAP) was applied and tested to reduce dishing and erosion in this paper. The abrasive concentration decrease of FAP results in advanced pattern selectivity which can lead the uniform removal in chip and declining over-polishing. Consequently, reduced dishing and erosion was observed in CMP of tungsten pattern wafer with proposed FAP and chemicals.