• Journal of Electrochemical Science and Technology
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• 제5권4호
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• pp.115-127
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• 2014

Cd-Pb thin films were electrodeposited from a diluted chloride solution using stainless steel rotating disc electrode. The linear sweep voltammograms of the single metallic ions show that electrodeposition of these ions was mass transfer control due to the plateau observed for different rotations at concentration (50 and 200 ppm). The voltammograms of binary system elucidate that electrodeposition process always start at cathodic potential located between the potential of individual metals. Currents transients measurements, anodic linear sweep voltammetry (ALSV) and atomic force microscopy (AFM) were used to characterize the electrocryatalization process and morphology of thin films. ALSV profiles show a differentiation for the dissolution process of individual metals and binary system. Two peaks of dissolution Cd-Pb film were observed for the binary system with different metal ion concentration ratios. The model of Scharifker and Hills was used to analyze the current transients and it revealed that Cd-Pb electrocrystalization processes at low concentration is governed by three-dimensional progressive nucleation controlled by diffusion, while at higher concentration starts as a progressive nucleation then switch to instantaneous nucleation process. AFM images reveal that Cd-Pb film electrodeposited at low concentration is more roughness than Cd-Pb film electrodeposited at high concentrated solution.

• 한국진공학회:학술대회논문집
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• 한국진공학회 2009년도 제38회 동계학술대회 초록집
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• pp.229-229
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• 2010

With the scaling down of ultra large integrated circuits (ULSI) to the sub-50 nm technology node, the need for an ultra-thin, continuous and conformal diffusion barrier and Cu seed layer is increasing. However, diffusion barrier and Cu seed layer formation with a physical vapor deposition (PVD) method has become difficult as the technology node is reduced to 30 nm and beyond. Recent work on self-forming barrier processes using PVD Cu alloys have attracted great attention due to the capability of conformal ultra-thin barrier formation using a simple technique. However, as in the case of the conventional barrier and Cu seed layer, PVD of the Cu alloy seed layer will eventually encounter the difficulty in conformal deposition in narrow line trenches and via holes. Atomic layer deposition (ALD) has been known for its good step coverage and precise thickness control, and is a candidate technique for the formation of a thin conformal barrier layer and Cu seed layer. Conformal Cu-Mn seed layers were deposited by plasma enhanced atomic layer deposition (PEALD) at low temperature ($120^{\circ}C$), and the Mn content in the Cu-Mn alloys were controlled form 0 to approximately 10 atomic percent with various Mn precursor feeding times. Resistivity of the Cu-Mn alloy films decreased by annealing due to out-diffusion of Mn atoms. Out-diffused Mn atoms were segregated to the surface of the film and interface between a Cu-Mn alloy and $SiO_2$, resulting in self-formed $MnO_x$ and $MnSi_xO_y$, respectively. No inter-diffusion was observed between Cu and $SiO_2$ after annealing at $500^{\circ}C$ for 12 h, indicating an excellent diffusion barrier property of the $MnSi_xO_y$. The adhesion between Cu and $SiO_2$ was enhanced by the formation of $MnSi_xO_y$. Continuous and conductive Cu-Mn seed layers were deposited with PEALD into 32 nm $SiO_2$ trench, enabling a low temperature process, and the trench was perfectly filled using electrochemical plating (ECD) under conventional conditions. Thus, it is the resultant self-forming barrier process with PEALD Cu-Mn alloy film as a seed layer for plating Cu that has further potential to meet the requirement of the smaller than 30 nm node.

• 대한화학회지
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• 제35권4호
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• pp.405-409
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• 1991

비양성자성용매인 아세토니트릴 중에서 Copper-1-(2-thiazolylazo)-2-naphthol(이하 Cu(II)-TAN으로 줄임) 착물의 전기화학적 성질을 조사하였다. 착물의 직류폴라로그램으로부터 환원전류의 유형과 가역성 및 양성자 주게인 물의 첨가에 따른 영향을 검토하였다. 그리고 환원반응에 관여한 전자수는 일정전위 전기분해법으로 구하였다. 또 일정전위 전기분해한 전해생성물의 UV-Vis Spectrum으로부터 전해생성물을 확인하였다. 이상의 실험 결과로부터 아세토니트릴 용매 중에서 Cu(II)-TAN 착물은 3단계의 환원과정을 거쳐 최종적으로 아민화합물이 됨을 알았다. 이 때 1단계 환원과정에서는 anion radical이 생성되는 과정이고, 2단계 환원과정에서는 dianion이 생성되는 과정이다. 또 1단계와 2단계의 환원과정은 모두 가역성이 좋은 편이었으나 3단계 환원과정은 가역성이 매우 나쁜 편이었다. 또한 각 단계의 환원전류는 확산지배적이었다.

• 한국산업보건학회지
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• 제22권1호
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• pp.52-59
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• 2012

Objectives: The purpose of this study was to evaluate the exposure possibility of by-products during the semiconductor manufacturing processes. Methods: The authors investigated types of chemicals generated during semiconductor manufacturing processes by the qualitative experiment on generation of by-products at the laboratory and a literature survey. Results: By-products due to decomposition of photoresist by UV-light during the photo-lithography process, ionization of arsine during the ion implant process, and inter-reactions of chemicals used at diffusion and deposition processes can be generated in wafer fabrication line. Volatile organic compounds (VOCs) such as benzene and formaldehyde can be generated during the mold process due to decomposition of epoxy molding compound and mold cleaner in semiconductor chip assembly line. Conclusions: Various types of by-products can be generated during the semiconductor manufacturing processes. Therefore, by-products carcinogen such as benzene, formaldehyde, and arsenic as well as chemical substances used during the semiconductor manufacturing processes should be controlled carefully.

• Korean Chemical Engineering Research
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• 제56권3호
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• pp.430-434
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• 2018

본 연구에서는 잔류 메틸렌 클로라이드 제거를 위한 마이크로웨이브를 이용한 파클리탁셀 건조에서 유효확산계수 및 물질전달계수를 조사하였다. 모든 온도(35, 45, $55^{\circ}C$)에서 건조 초기에 많은 양의 잔류 메틸렌 클로라이드가 제거되었으며 건조 온도가 증가할수록 건조 효율은 증가하였다. 건조 온도가 증가할수록 파클리탁셀의 유효확산계수($1.299{\times}10^{-13}{\sim}2.571{\times}10^{-13}m^2/s$)와 물질전달계수($1.625{\times}10^{-11}{\sim}4.857{\times}10^{-11}m/s$)는 증가하였다. 또한 낮은 Biot 수(0.0100~0.0151)로부터 건조의 진행이 주로 파클리탁셀의 외부확산에 의해 조절됨을 알 수 있었다.

• 청정기술
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• 제15권4호
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• pp.253-257
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• 2009

LCD 제조공정에서 배출되는 질산과 초산, 인산, 그리고 Al과 같은 금속이온을 함유한 폐에칭액으로부터 진공증발과 확산투석을 이용하여 고순도 인산을 회수하여 인산암모늄을 제조하고자 하였다. 진공증발을 이용하여 질산과 초산을 제거하였다. 진공도가 -650 mmHg인 경우에는 온도 413 K 이상에서 완전 분리되었고, 진공도가 -700 mmHg인 경우에는 온도 393 K 이상의 영역에서 완전히 분리되었다. 그리고 진공도 -730 mmHg의 경우는 온도 383 K 이상에서도 완전 분리가 가능하였다. 99%의 질산과 초산을 제거하였으며, 확산투석을 이용하여 약 97.5% 이상의 Al을 제거하였다. 이렇게 얻어진 고순도 인산과 수산화암모늄을 이용하여 일인산암모늄을 제조하는 공정에서 급격한 발열반응을 제어하고 안정된 적정조건을 도출하기 위하여 수산화암모늄의 농도, 적정 몰비, pH, 온도 등의 반응인자를 조절하여 회수율 약 90%의 일인산암모늄을 제조하였다.

• 청정기술
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• 제7권3호
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• pp.187-194
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• 2001

석탄가스화 복합발전(IGCC)의 탈황공정에 사용되는 비아연계 탈황제 중 경제성이 우수한 천연망간광석을 이용하여 황화수소 제거반응에 대한 특성을 연구하였다. $H_2S$와 천연망간광석 탈황제 사이의 반응에 대한 초기 반응 속도를 $400{\sim}800^{\circ}C$의 온도범위에서 열중량 분석기로 실험하였다. 그 결과로 황화수소 제거반응 시 초기 반응은 1차 반응이었고, 반응속도상수는 Arrhenius 식에 잘 적용할 수 있었다. 또한 황화반응이 확산에 의해 제어되는 조건에서 농도 구배가 선형을 나타내었으며, 이를 통하여 유효 확산 계수를 온도에 따른 Arrhenius식으로 나타내었다. 이 결과를 통하여 황화 반응 시 확산에 대한 활성화 에너지와 반응 빈도 인자를 구하였다.

• 한국분말재료학회지
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• 제23권6호
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• pp.437-441
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• 2016

Recently, the grain boundary diffusion process (GBDP), involving heavy rare-earth elements such as Dy and Tb, has been widely used to enhance the coercivity of Nd-Fe-B permanent magnets. For example, a Dy compound is coated onto the surface of Nd-Fe-B sintered magnets, and then the magnets are heat treated. Subsequently, Dy diffuses into the grain boundaries of Nd-Fe-B magnets, forming Dy-Fe-B or Nd-Dy-Fe-B. The dip-coating process is also used widely instead of the GBDP. However, it is quite hard to control the thickness uniformity using dip coating. In this study, first, a $DyF_3$ paste is fabricated using $DyF_3$ powder. Subsequently, the fabricated $DyF_3$ paste is homogeneously coated onto the surface of a Nd-Fe-B sintered magnet. The magnet is then subjected to GBDP to enhance its coercivity. The weight ratio of binder and $DyF_3$ powder is controlled, and we find that the coercivity enhances with decreasing binder content. In addition, the maximum coercivity is obtained with the paste containing 70 wt% of $DyF_3$ powder.

• 한국결정학회지
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• 제16권2호
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• pp.89-101
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• 2005

Among many material processing related issues for successful scaling down of devices for the next 10 years or so, the advanced gate stack and interconnect technology are two most critical research areas, which need technical innovation. The introduction of new metallic films and appropriate processing technologies are required more than ever. Especially, as the device downscaling continues well into sub 50 nm regime, the paradigm for metal nano film deposition technique research has been shifted to high conformality, low growth temperature, high quality with uniformity at large area wafers. Regarding these, ALD has sparked a lot of interests for a number of reasons. The process is intrinsically atomic in nature, resulting in the controlled deposition of films in sub-monolayer units with excellent conformality. In this paper, the overview on the current issues and the future trends in device processing technologies related to metal nano films as well as the R&D trends in these applications will be discussed. The focus will be on the applications for metal gate, capacitor electrode for DRAM, and diffusion barriers/seed layers for Cu interconnect technology.

• Journal of Electrical Engineering and Technology
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• 제6권1호
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• pp.119-122
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• 2011

A new high speed AFM probe has been proposed and fabricated. The probe is integrated with PZT actuated cantilever realized in bulk silicon wafer using heavily boron doped silicon as an etch stop layer. The cantilever thickness can be accurately controlled by the boron diffusion process. Thick SCS cantilever and integrated PZT actuator make it possible to be operated at high speed for fast imaging. The resonant frequency of the fabricated probe is 92.9 kHz and the maximum deflection is 5.3 ${\mu}m$ at 3 V. The fabricated probe successfully measured the surface of standard sample in an AFM system at the scan speed of 600${\mu}m$/sec.