• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 2001년도 추계학술대회 논문집 Vol.14 No.1
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• pp.217-220
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• 2001

The possibility of cerium dioxide $(CeO_2)$ thin films as insulators of metal erroelectric insulator semiconductor (MFIS) structures have been studied. The etching $CeO_2$ thin films have been perfonned in an inductively coupled $Cl_{2}/CF_{4}/Ar$ plasma. The high etch rate of the $CeO_2$ thin film was $250\AA /m$ at a 10 % addition of $Cl_2$ into the $Ar(80)/CF_{4}(20)$. The surface reaction of the etched $CeO_2$ thin films was investigated using X-ray photoelectron spectroscopy (XPS) analysis. There are Ce-Cl and Ce-F bonding by chemical reaction between Cl, F and Ce. These products can be removed by the physical bombardment of incident Ar ions.

• 한국세라믹학회지
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• 제47권5호
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• pp.439-444
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• 2010

The usual ceramic process of mixing and milling in state of oxide of $ZrO_2$ and $CeO_2$ was adopted in wet process to manufacture Ce-TZP in this study. The maximum dispersion point of every slurry manufactured with mixture of $ZrO_2$ and $CeO_2$ was neat at pH10. The stable slurry in average particle size of 90 nm can be manufactured when it is dispersed with use of ammonia water and polycarboxylic acid ammonium. The sintered Ce-TZP ceramics manufactured with addition of $CeO_2$ less than 10 mol% was progressed to the fracture of specimen due to the monoclinic phase existence more than 30% at the room temperature. More than 99% of tetragonal phase was created for the sintered body with addition of $CeO_2$ beyond 18 mol%, but the mechanical property degrade on the entire specimen was brought due to the $CeO_2$ existing above 3%. Consequently, the optimal Ce-TZP combined in oxide state was identified in 16 mol% of $CeO_2$ contents.

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 2001년도 추계학술대회 논문집
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• pp.217-220
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• 2001

The possibility of cerium dioxide (CeO$_{7}$ ) thin films as insulators of metal erroelectric insulator semiconductor (MFIS) structures have been studied. The etching CeO$_2$ thin films have been performed in an inductively coupled C1$_2$/CF$_4$/Ar plasma. The high etch rate of the CeO$_2$ thin film was 250 ${\AA}$/m at a 10% addition of Cl$_2$ into the Ar(80)/CF$_4$(20). The surface reaction of the etched CeO$_2$ thin films was investigated using X-ray photoelectron spectroscopy (XPS) analysis. There are Ce-Cl and Ce-F bonding by chemical reaction between Cl, F and Ce. These products can be removed by the physical bombardment of incident Ar ions.

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 2008년도 하계학술대회 논문집 Vol.9
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• pp.118-118
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• 2008

The oxide CMP has been applied to interlayer dielectric(ILD) and shallow trench isolation (STI) in chip fabrication. Recently the slurry used in oxide CMP being changed from silica slurry to ceria (cerium dioxide) slurry particularly in STI CMP, because the material selectivity of ceria slurry is better than material selectivity of silica slurry. Moreover, the ceria slurry has good a planarization efficiency, compared with silica slurry. However ceria abrasives make a material removal rate too high at the region of wafer center. Then we focuses on why profile of material removal rate is convex. The material removal rate sharply increased to 3216 $\AA$/min by $4^{th}$ run without conditioning. After $4^{th}$ run, material removal rate converged. Furthermore, profile became more convex during 12 run. And average material removal rate decreased when conditioning process is added to end of CMP process. This is due to polishing mechanism of ceria. Then the ceria abrasive remains at the pad, in particular remains more at wafer center contacted region of pad. The field emission scanning electron microscopy (FE-SEM) images showed that the pad sample in the wafer center region has a more ceria abrasive than in wafer outer region. The energy dispersive X-ray spectrometer (EDX) verified the result that ceria abrasive is deposited and more at the region of wafer center. Therefore, this result may be expected as ceria abrasives on pad surface causing the convex profile of material removal rate.

• 한국전기전자재료학회논문지
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• 제14권9호
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• pp.695-699
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• 2001

Cerium dioxide (CeO$_2$) was used as the intermediate layer between the ferroelectric thin film and Si substrate in a metal-ferroelectric-semiconductor field effect transistor (MFSFET), to improve the interface property by preventing the interdiffusion of the ferroelectric material and the Si substrate. In this study, CeO$_2$ thin films were etched with a CF$_4$/Ar gas combination in inductively coupled plasma (ICP). The maximum etch rate of CeO$_2$ thin films was 270$\AA$/min under CF$_4$/(CF$_4$+Ar) of 0.2, 600 W/-200V, 15 mTorr, and $25^{\circ}C$. The selectivities of CeO$_2$ to PR and SBT were 0.21, 0.25, respectively. The surface reaction in the etching of CeO$_2$ thin films was investigated with x-ray photoelectron spectroscopy (XPS). There is a chemical reaction between Ce and F. Compounds such as Ce-F$_{x}$ remains on the surface of CeO$_2$ thin films. Those products can be removed by Ar ion bombardment. The results of secondary ion mass spectrometry (SIMS) were consistent with those of XPS. Scanning electron microscopy (SEM) was used to examine etched profiles of CeO$_2$ thin films. The etch profile of over-etched CeO$_2$ films with the 0.5${\mu}{\textrm}{m}$ line was approximately 65$^{\circ}$.>.

• 대한화학회지
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• 제37권4호
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• pp.390-395
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• 1993

비화학량론적 화합물 $CeO_2-x의 비호학량 x값과 전기전도도를 600~1200$^{\circ}C$의 온도 범위와 $2{\times}10^{-1}{\sim}1{\times}10^{-4}$ atm이 산소분압 범위에서 측정하였다. 결함생성 엔탈피는 흡열과정임을 보이며 산소분압의존성 도는 1/n 값은 -1/3.18 ∼ -1/3.69까지 변하였다. 전기전도도의 활성화에너지와 1/n값은 각각 1.75 eV 와 -1/4이었다. 비화학량 x값, 전기전도도 $\sigma$값 및 열역학적 데이타로부터 이산화세륨의 결함구조는 1가로 하전된 산소공위이며 과잉금속이 전도성 전자주게의 역할을 하는 n-형 반도체이다.

• 청정기술
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• 제29권4호
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• pp.321-326
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• 2023

최근 탄소중립과 관련하여 연소 시 이산화탄소 배출이 없어 청정한 수소에너지에 대한 관심이 증가하고 있다. 이에 따라 수소 생산에 관련된 연구가 계속되고 있으며 본 연구에서는 폐기물을 처리함과 동시에 고순도 수소를 생산하기 위해 폐기물 유래 합성가스를 수성가스전이반응에 적용하였다. 마그네슘을 세륨과 함께 지지체로 사용하여 고온수성가스전이(HT-WGS)반응에서 촉매의 활성을 향상시키고자 하였다. HT-WGS 반응의 활성물질로 구리를 사용해 Cu-CeO₂-MgO 촉매를 제조하였으며, 제조방법에 따른 촉매활성 연구를 진행하였다. HT-WGS 반응 결과 함침법으로 제조된 Cu-CeO₂-MgO 촉매가 가장 높은 활성을 보였으며, 이는 가장 높은 산소 저장능과 많은 활성 Cu 종을 가지는 특성에 기인한 결과이다.