• Transactions on Electrical and Electronic Materials
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• 제13권2호
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• pp.78-84
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• 2012

An in-situ optical monitoring method for real-time process monitoring of electrochemical copper deposition (CED) is presented. Process variables to be controlled in achieving desired process results are numerous in the CED process, and the importance of the chemical bath conditions cannot be overemphasized for a successful process. Conventional monitoring of the chemical solution for CED relies on the pH value of the solution, electrical voltage level for the reduction of metal cations, and gravity measurement by immersing sensors into a plating bath. We propose a nonintrusive optical monitoring technique using three types of optical sensors such as chromatic sensors and UV/VIS spectroscopy sensors as potential candidates as a feasible optical monitoring method. By monitoring the color of the plating solution in the bath, we revealed that optically acquired information is strongly related to the thickness of the deposited copper on the wafers, and that the chromatic information is inversely proportional to the ratio of $Cu$ (111) and {$Cu$ (111)+$Cu$ (200)}, which can used to measure the quality of the chemical solution for electrochemical copper deposition in advanced interconnection technology.

• 공업화학
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• 제34권4호
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• pp.383-387
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• 2023

범용적으로 고진공 성막 장비에서 사용되는 quartz crystal microbalance (QCM)는 두꺼운 필름이 quartz 위에 성막되는 경우, 크리스탈 고유의 진동에 영향을 주어 사용이 어려워진다. 본 논문에서는 실시간 필름 증착 공정 중에 센서의 손상이 없는 광학적 계측 방식을 통해 필름의 성막 속도를 측정하는 방법을 연구하였다. 기체 이동 경로로 지나가는 페럴린 가스 중 다이머에 의한 레이저의 산란 정도를 측정하여, 페럴린 공정의 분해부 온도가 감소할수록 페럴린 가스 중 다이머의 비율이 증가하는 것을 성공적으로 확인하였다. 또한, 성막된 필름의 특성을 확인한 결과, 분해부 온도가 감소할수록 필름의 두께와 haze가 증가한 것을 확인할 수 있었다. 우리는 연구 결과를 통해 개발한 안정적인 실시간 성막 속도 계측 시스템을 이용함으로써, 진공 공정을 통해 성막하는 페럴린 필름의 정밀한 성막 속도 제어에 활용하고자 한다.

• 터널과지하공간
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• 제10권2호
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• pp.237-248
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• 2000

역학적으로 안정한 공동 및 처분공 간격을 결정하기 위해, 현재 수행 중인 열 해석의 중간 결과를 근거로 범용 해석 프로기램인 ABAQUS 버전 5.8을 이용해 3차원 유한요소해석을 수행하였다. 세 가지 초기지압을 조건으로 공동간격과 처분공 간격을 바꿔가면서 선형탄성해석을 수행하였고. 그 결과를 분석하여 굴착 후 응력재분배에 의한 암반의 거동은 어떤 경향을 가지고 있으며, 적절한 공동 간격 및 처분공 간격은 어느 정도가 좋은지를 분석하였다. 또한 각 경우 역학적인 안전계수는 어느 정도인지도 계산하였다. 국내지압분포를 근거로 도출한 초기지압 하에서는 공동간격 40m, 처분공간격 3m인 경우 안전계수 3.42가 계산되어 아주 안정한 결과를 얻었고, 스웨덴이나 캐나다의 초기지압 경힘식의 경우의 안전계수는 각각 1.19와 1.27로 비교적 낮은 값이지만 1 이상의 값이므로 응력재분배로 인한 파괴는 일어나지 않는다는 결과를 얻었다.

• 한국진공학회:학술대회논문집
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• 한국진공학회 2013년도 제44회 동계 정기학술대회 초록집
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• pp.619-619
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• 2013

The interfacial state between $Ta_2O_5$ and a Si substrate during the growth of $Ta_2O_5$ films by atomic layer deposition (ALD) was investigated using in-situ synchrotron radiation photoemission spectroscopy (SRPES). A newly synthesized liquid precursor Ta($N^tBu$) $(dmamp)_2Me$ was used as the metal precursor, with Ar as a purging gas and $H_2O$ as the oxidant source. After each half reaction cycle, samples were analyzed using in-situ SRPES under ultrahigh vacuum at room temperature. SRPES analysis revealed that Ta suboxide and Si dioxide were formed at the initial stages of $Ta_2O_5$ growth. However, the Ta suboxide states almostdisappeared as the ALD cycles progressed. Consequently, the $Ta^{5+}$ state, which corresponds with the stoichiometric $Ta_2O_5$, only appeared after 4.0 cycles. Additionally, tantalum silicate was not detected at the interfacial states between $Ta_2O_5$ and Si. The measured valence band offset between $Ta_2O_5$ and the Si substrate was 3.22 eV after 3.0 cycles.

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 2004년도 춘계학술대회 논문집 반도체 재료 센서 박막재료 전자세라믹스
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• pp.97-100
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• 2004

We have grown GaN layers with in-situ SiN mask by metal organic chemical vapor deposition (MOCVD) and study the characteristic of the GaN layer. We have changed the deposition time of SiN mask from 45s to 5min and obtain th optimum condition in 45s. The PL intensity of GaN with SiN mask improved 2 times to that without SiN mask and the carrier concentraion increased from $3.5{\times}10^{16}cm^{-3}$ to $1.8{\times}10^{17}cm^{-3}$. We have thus shown that the SiN mask improved significantly the optical properties of the GaN layer.

• 한국전기전자재료학회논문지
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• 제18권6호
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• pp.582-586
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• 2005

We have grown GaN layers with in-situ SiN mask by metal organic chemical vapor deposition (MOCVD) and study the physical properties of the GaN layer. We have also investigate the effect of the SiN mask on its optical property. By inserting a SiN mask, (102) the full width at half maximum (FWHM) decreased from 480 arcsec to 409 arcsec and threading dislocation (TD) density decreased from $3.21\times10^9\;cm^{-2}\;to\;9.7\times10^8\;cm^{-2}$. The PL intensity of GaN with SiN mask improved 2 times to that without SiN mask. We have thus shown that the SiN mask improved significantly the physical and optical properties of the GaN layer.

• 한국초전도ㆍ저온공학회논문지
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• 제14권4호
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• pp.5-11
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• 2012

In this review article, we focus on various co-evaporation technologies developed for the fabrication of high performance $REBa_2Cu_3O_{7-{\delta}}$ (RE: Y and Rare earth elements, REBCO) superconducting films. Compared with other manufacturing technologies for REBCO films such as sputtering, pulsed laser deposition (PLD), metal-organic deposition (MOD), and metal organic chemical vapor deposition (MOCVD), the co-evaporation method has a strong advantage of higher deposition rate because metal sources can be used as precursor materials. After the first attempt to produce REBCO films by the co-evaporation method in 1987, various co-evaporation technologies for high performance REBCO films have been developed during last several decades. The key points of each co-evaporation technology are reviewed in this article, which enables us to have a good insight into a new high throughput process, called as a Reactive Co-Evaporation by Deposition and Reaction (RCE-DR).

• 한국진공학회:학술대회논문집
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• 한국진공학회 2011년도 제41회 하계 정기 학술대회 초록집
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• pp.222-222
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• 2011

Titanium dioxide (TiO2) has a number of applications in optics and electronics due to its superior properties, such as physical and chemical stability, high refractive index, good transmission in vis and NIR regions, and high dielectric constant. Atomic layer deposition (ALD), also called atomic layer epitaxy, can be regarded as a special modification of the chemical vapor deposition method. ALD is a pulsed method in which the reactant vapors are alternately supplied onto the substrate. During each pulse, the precursors chemisorb or react with the surface groups. When the process conditions are suitably chosen, the film growth proceeds by alternate saturative surface reactions and is thus self-limiting. This makes it possible to cover even complex shaped objects with a uniform film. It is also possible to control the film thickness accurately simply by controlling the number of pulsing cycles repeated. We have investigated the ALD of TiO2 at 100$^{\circ}C$ using precursors titanium tetra-isopropoxide (TTIP) and H2O on -O, -OH terminated Si surface by in situ X-ray photoemission spectroscopy. ALD reactions with TTIP were performed on the H2O-dosed Si substrate at 100$^{\circ}C$, where one cycle was completed. The number of ALD cycles was increased by repeated deposition of H2O and TTIP at 100$^{\circ}C$. After precursor exposure, the samples were transferred under vacuum from the reaction chamber to the UHV chamber at room temperature for in situ XPS analysis. The XPS instrument included a hemispherical analyzer (ALPHA 110) and a monochromatic X-ray source generated by exciting Al K${\alpha}$ radiation (h${\nu}$=1486.6 eV).

• 한국재료학회:학술대회논문집
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• 한국재료학회 1999년도 추계학술발표강연 및 논문개요집
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• pp.85-85
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• 1999

• 한국재료학회:학술대회논문집
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• 한국재료학회 2007년도 추계학술발표대회 및
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• pp.13.2-13.2
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• 2007