• 한국세라믹학회지
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• 제37권3호
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• pp.280-287
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• 2000

Adsorption behavior and amount of phenolic resin followed silica (SiO2) formation onto silicon nitride(Si3N4) surface were investigated using electrokinetic sonic amplitude (ESA) technique and with UV spectrometer, to fabricate Si3N4/SiC nano-composite based on reaction between SiO2 formed and phenolic resin absorbed onto Si3N4 particle. The amount of SiO2 formed and carbon from phenolic resin absorbed onto Si3N4 surface were calculated quantitatively to adjust the reaction between SiO2 and phenolic resin, resulting in no residual SiO2 and carbon. As a result, pre-heated tempeature for optimized reaction was below 25$0^{\circ}C$, in which there was no residual SiO2 and carbon.

• 대한전기학회논문지:전기물성ㆍ응용부문C
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• 제48권6호
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• pp.494-502
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• 1999

This paper represents an electrostatic micro plate resonator which consists of a rigid plate suspended with four bridges and a counter electrode. The bridges of the resonator are designed corrugated so that the residual stress are released. The FEM simulation results confirmed that the deflection characteristic of the corrugated bridge is hardly affected by the initial residual tensile stress. One resonator with the corrugated bridges and the other with the flat bridges were fabricated by the boron diffusion process and the anisotropic etch process. The vertical deflection of the fabricated electrostatic resonator was measured with a laser vibrometer, and the data were compared with the calculation results. The deflection of the resonator with the flat bridges is smaller than the deflection of that with the corrugated ones because of the residual stress. The residual stress release effect was confirmed by the fact that the measured deflection of the resonator with the corrugated bridges in close to the calculated deflection of the resonator with the flat ones with the initial stress neglected.

• 한국산학기술학회논문지
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• 제8권1호
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• pp.25-32
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• 2007

코발트 니켈 합금형 실리사이드 공정에서 단결정실리콘과 다결정실리콘 기판에 자연산화막이 있는 경우 나노급 두께의 코발트 니켈 합금 금속을 증착하고 실리사이드화하는 경우의 반응 안정성을 확인하였다. 4인치 P-type(100)Si 기판 전면에 poly silicon을 입힌 기판과 single silicon 상태의 두 종류 기판을 준비하고 두께 4 nm의 자연산화막이 있는 상태에서 10 nm 코발트 니켈 합금을 니켈의 상대조성을 $10{\sim}90%$로 달리하며 열증착하였다. 통상의 600, 700, 800, 900, 1000, $1100^{\circ}C$ 각 온도에서 실리사이드화 열처리를 시행 후 잔류 합금층을 제거하고, XRD(X-ray diffraction)및 FE-SEM(Field emission scanning electron microscopy), AES(Auger electron spectroscopy)를 사용하여 실리사이드가 생겼는지 확인하였다. 마이크로라만 분석기로 실리사이드 반응시의 실리콘 층의 잔류 스트레스도 확인하였다. 자연산화막이 존재하는 경우 실리사이드 반응이 진행되지 않았고, 폴리실리콘 기판과 고온에서는 금속과 산화층의 반응잔류물이 생성되었다. 단결정 기판의 고온열처리에서는 실리사이드 반응이 없더라도 핀홀이 발생할 수 있는 정도의 열스트레스가 존재하였다. 코발트 니켈 복합실리사이드 공정에서는 자연산화막을 제거하는 공정이 필수적이었다.

• 한국방사성폐기물학회:학술대회논문집
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• 한국방사성폐기물학회 2018년도 춘계학술논문요약집
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• pp.377-378
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• 2018

• 한국재료학회지
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• 제28권2호
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• pp.124-128
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• 2018

N-type porous silicon (PS) layers and thermally oxidized PS layers have been characterized by various measuring techniques such as photoluminescence (PL), Raman spectroscopy, IR, HRSEM and transmittance measurements. The top surface of PS layer shows a stronger photoluminescence peak than its bottom part, and this is ascribed to the difference in number of fine silicon particles of 2~3 nm in diameter. Observed characteristics of PL spectra are explained in terms of microstructures in the n-type PS layers. Common features for both p-type and n-type PS layers are as follows: the parts which can emit visible photoluminescence are not amorphous, but crystalline, and such parts are composed of nanocrystallites of several nm's whose orientations are slightly different from Si substrate, and such fine silicon particles absorb much hydrogen atoms near the surfaces. Light emission is strongly dependent on such fine silicon particles. Photoluminescence is due to charge carrier confinement in such three dimensional structure (sponge-like structure). Characteristics of visible light emission from n-type PS can be explained in terms of modification of band structure accompanied by bandgap widening and localized levels in bandstructure. It is also shown that hydrogen and oxygen atoms existing on residual silicon parts play an important role on emission stability.

• 한국기계가공학회지
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• 제13권6호
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• pp.139-144
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• 2014

As a result of a mismatch of the residual stress between both sides of the silicon wafer, which warps and distorts during the patterning process. The accuracy of the warpage measurement is related to the calibration. A CCD camera was used for the calibration. Performing optimization of the error function constructed with phase values measured at each pixel on the CCD camera, the coordinates of each light source can be precisely determined. Measurement results after calibration was performed to determine the warpage of the silicon wafer demonstrate that the maximum discrepancy is $5.6{\mu}m$ with a standard deviation of $1.5{\mu}m$ in comparison with the test results obtained by using a Form TalySurf instrument.

• 대한전기학회:학술대회논문집
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• 대한전기학회 1994년도 추계학술대회 논문집 학회본부
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• pp.413-415
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• 1994

In this paper, a new technique for quantitative estimation of the stress profile along the depth of $p^+$ silicon films is presented. The $p^+$ silicon cantilevers with various beam thickness and a rotating beam supported by two cantilevers are used for estimating the stress profile of the films. The average of the residual stress distribution is estimated to be 50MPa. Most of $p^+$ silicon films are subjected to the tensile stress, except the region near the frontside.

• 한국재료학회지
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• 제22권1호
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• pp.8-15
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• 2012

Silicon-based thin film was prepared at room temperature by an electrochemical deposition method and a feasibility study was conducted for its use as an anode material in a rechargeable lithium battery. The growth of the electrodeposits was mainly concentrated on the surface defects of the Cu substrate while that growth was trivial on the defect-free surface region. Intentional formation of random defects on the substrate by chemical etching led to uniform formation of deposits throughout the surface. The morphology of the electrodeposits reflected first the roughened surface of the substrate, but it became flattened as the deposition time increased, due primarily to the concentration of reduction current on the convex region of the deposits. The electrodeposits proved to be amorphous and to contain chlorine and carbon, together with silicon, indicating that the electrolyte is captured in the deposits during the fabrication process. The silicon in the deposits readily reacted with lithium, but thick deposits resulted in significant reaction overvoltage. The charge efficiency of oxidation (lithiation) to reduction (delithiation) was higher in the relatively thick deposit. This abnormal behavior needs to clarified in view of the thickness dependence of the internal residual stress and the relaxation tendency of the reaction-induced stress due to the porous structure of the deposits and the deposit components other than silicon.

• 센서학회지
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• 제9권4호
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• pp.297-306
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• 2000

최근 MEMS 소자의 성능향상을 위하여 수십 ${\mu}m$의 두께를 가지는 고형상비 단결정실리콘 구조물 제작에 관한 연구가 활발하게 진행되고 있다. 그러나 이러한 고형상비 단결정실리콘 구조물 제작 기술에서는 구조물의 구동 또는 전기신호의 검지를 위한 전극 사이의 전기적인 절연 방법이 주된 문제로서 대두되고 있다. 본 논문에서는 고형상비를 가지는 단결정실리콘 구조물 전극 간의 전기적 절연을 위하여 고형상비 산화막으로 구성된 빔 및 측벽을 이용한 새로운 절연 기술을 개발하였다. 개발된 절연 기술은 실리콘 구조물을 측면 또는 하부에서 산화막으로 지지하는 절연 구조를 가진다. 이러한 트렌치 산화막은 그 깊이가 수십 ${\mu}m$이므로 산화막의 잔류응력이 구조물에 미치는 영향을 반드시 고려하여야 한다. 본 논문에서는 PECVD 방법으로 증착한 TEOS 산화막으로 절연 구조들을 제작하였으며, 제작된 절연구조들의 잔류응력을 측정하고, 그 잔류응력이 구조물에 미치는 영향을 해석하였다. 또한 공진자를 이용하여 개발된 절연 기술이 고형상비 단결정실리콘 구조물에 효과적으로 쓰일 수 있음을 보였다.

• Journal of Advanced Marine Engineering and Technology
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• 제25권3호
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• pp.631-635
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• 2001

The major problems associated with the manufacturing processes of the microaccelerometer based on the tunneling current concept is the residual stress. This paper deals with finite element analysis of residual stress causing pop up phenomenon which are induced in micromachining processes for a microaccelerometers sensor using silicon on insulator(SOI) wafer. After heating the tunnel gap up to $100^{\circ}C$and get it through cooling process and the additional beam up to $80^{\circ}C$get it through the cooling process. We learn the residual stress of each shape and compare the results with each other, after heating the tunnel gap up to $400^{\circ}Cduring$ the Pt deposition process. The equivalent stresses produced during the heating process of focused ion beam(FIB) cut was also to be about $0.02~0.25Pa/^{\circ}C$and cooling process the gradient of residual stresses of about $8.4\{times}10^2Pa/{\mu}m$ still at cantilever beam and connected part of paddle. We want to seek after the real cause of this pop up phenomenon and diminish this by change manufacturing processes of microaccelerometer sensors.