• 전기화학회지
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• 제13권1호
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• pp.70-74
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• 2010

전기화학 반응을 이용한 실리콘 표면상으로의 단백질 고정을 연구하였다. 이를 위해 Nitrobenzendiazonium(NiBD) 양이온을 화학적 환원반응을 통해 수식하고 수식된 실리콘 표면을 전기화학적으로 다시 환원시켜 나이트로 기능기를 일차아민 기능기로 활성화하여 단백질 고정에 이용하였다. 활성화 된 표면에 금 나노입자를 고정하여 일차 아민 생성을 확인하였다. 또한 이 방법을 응용하여 실리콘 나노선 어레이 중 선택된 나노선 만을 활성화하고 단백질을 선택적으로 고정하는 연구를 수행하였다. 이 연구를 통하여 NiBD 양이온의 화학 및 전기화학 반응이 실리콘 나노선 표면으로 단백질의 선택적 고정화에 유용하게 사용될 수 있음을 보였다.

• 한국표면공학회지
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• 제28권1호
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• pp.55-63
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• 1995

Alkaline solutions such as $NH_4$OH, choline and TMAH (($CH_3$)$_4$NOH) have been introduced in semiconductor wet processing of silicon wafers to control ionic and particulate impurities following etching in acidic solutions. These chemicals usually mixed with hydrogen peroxide and/or surfactants to control the etch rate of silicon. The highest etch rate was observed in $NH_4$OH solutions at a pH in alkaline solutions. It indicates that the etch rate depends on the content of $OH^{-}$ as well as cations of alkaline solutions. STM/AFM techniques were used to characterize the effect of alkaline solutions on silicon surface roughness. In SC1 (mixture of $NH_4$OH : $H_2$$O_2$ : $H_2$O) solutions, the reduction of the ammonium hydroxide proportion from 1 to 0.1 decreased the surface roughness ($R_{rms}$) from 6.4 to $0.8\AA$. The addition of $H_2$$O_2$ and surfactants to choline and TMAH reduced the values of $R_{p-v}$ and $R_{rms}$ significantly. $H_2$$_O2$ and surfactants added in alkaline solutions passivate bare silicon surfaces by the oxidation and adsorption, respectively. The passivation of surfaces in alkaline solutions resulted in lower etch rate of silicon thereby provided smoother surfaces.s.ces.s.

• 한국윤활학회:학술대회논문집
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• 한국윤활학회 1999년도 제30회 추계학술대회
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• pp.84-93
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• 1999

Sliding friction and wear tests for silicon nitride(Si$_3$N$_4$) was carried out with a ball-on-disk specimen configuration. The material used in this study was HIPed silicon nitride. The tests was carried out from room temperature to 1000"I with self mated couples of slicon nitride in laboratory air. Worn surfaces were observed by SEM and debris particles from worn surfaces were analyzed degree of oxidation by XPS. XPS.

• Korean Chemical Engineering Research
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• 제55권2호
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• pp.275-278
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• 2017

Heterogeneous semiconductor composites have been widely used to establish high-performance microelectronic or optoelectronic devices. During a deposition of silicon atoms on silicon/germanium compound surfaces, germanium (Ge) atoms are segregated from the substrate to the surface and are mixed in incoming a silicon layer. To suppress Ge segregation to obtain the interface sharpness between silicon layers and silicon/germanium composite layers, approaches have used silicon hydride gas species. The hydrogen atoms can play a role of inhibitors of silicon/germanium exchange. However, there are few kinetic models to explain the hydrogen effects. We propose using segregation probability which is affected by hydrogen atoms covering substrate surfaces. We derived the model to predict the segregation probability as well as the profile of Ge fraction through layers by using chemical reactions during silicon deposition.

• 전기화학회지
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• 제12권1호
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• pp.40-46
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• 2009

실리콘 표면을 전기화학적으로 활성화하여 활성화된 표면에만 선택적으로 단백질이나 나노입자 등의 기능성 물질을 고정화하는 방법을 개발하였다. 이를 위해 Carboxymethylbenzendiazonium (CMBD) 양이온을 전기화학적 환원반응을 통해 고정하여 실리콘 표면을 활성화하는 방식을 선택하였다. 그리고 활성화 된 표면에서만 기능성 물질이 고정된 것을 확인함을 통하여 CMBD 양이온의 사용이 선택적 고정화에 매우 효과적임을 보였다. 나아가 이 방법을 응용하여 실리콘 나노소자에 탑재된 실리콘 나노선 어레이 중 선택된 나노선의 표면만을 활성화하고 금 나노입자를 선택적으로 고정하는 연구를 수행하였다.

• KSTLE International Journal
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• 제8권2호
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• pp.26-28
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• 2007

Si(100) surfaces were topographically modified i.e. the surfaces were patterned at micro-scale using photolithography and DRIE (Deep Reactive Ion Etching) fabrication techniques. The patterned shapes included micro-pillars and microchannels. After the fabrication of the patterns, the patterned surfaces were chemically modified by coating a thin DLC film. The surfaces were then evaluated for their friction behavior at micro-scale in comparison with those of bare Si(100) flat, DLC coated Si(100) flat and uncoated patterned surfaces. Experimental results showed that the chemically treated (DLC coated) patterned surfaces exhibited the lowest values of coefficient of friction when compared to the rest of the surfaces. This indicates that a combination of both the topographical and chemical modification is very effective in reducing the friction property. Combined surface treatments such as these could be useful for tribological applications in miniaturized devices such as Micro-Electro-Mechanical-Systems (MEMS).

• 통합자연과학논문집
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• 제3권4호
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• pp.202-205
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• 2010

Nanocrystalline porous silicon surfaces have been used to detect nitroaromatic compounds in vapor phase. The mode of photoluminescence is emphasized as a sensing attitude or detection technique. Quenching of photoluminescence from nanocrystalline porous surfaces as a transduction mode is measured upon the exposure of nitroaromatic compounds. Reversible detection mode for nitroaromatics is, too, observed. To verify the detection afore-mentioned, photoluminescent freshly prepared porous silicons are functionalized with different groups. The mechanism of quenching of photoluminescence is attributed to the electron transfer behaviors of quantum-sized nano-crystallites in the porous silicon matrix to the analytes(nitroaromatics). An attempt has been done to prove that the surface-derivatized photoluminescent porous silicone surfaces can act as versatile substrates for sensing behaviors due to having a large surface area and highly sensitive transduction mode.

• KSTLE International Journal
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• 제9권1_2호
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• pp.10-12
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• 2008

Silicon micro-patterns were fabricated on Si (100) wafers using photolithography and DRIE (Deep Reactive Ion Etching) fabrication techniques. The patterned shapes included micro-pillars and micro-channels. After the fabrication of the patterns, the patterned surfaces were chemically modified by coating Z-DOL (perfluoropolyether, PFPE) thin films. The surfaces were then evaluated for their micro-friction behavior in comparison with those of bare Si (100) flat, Z-DOL coated Si (100) flat and uncoated Si patterns. Experimental results showed that the chemically treated (Z-DOL coated) patterned surfaces exhibited the lowest values of coefficient of friction when compared to the rest of the test materials. The results indicate that a combination of both the topographical and chemical modification is very effective in reducing the friction property. Combined surface treatments such as these could be useful for tribological applications in miniaturized devices such as Micro/Nano-Electro-Mechanical-Systems (MEMS/NEMS).

• 한국정밀공학회지
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• 제16권3호통권96호
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• pp.78-83
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• 1999

The bonding interface is dependent on the properties of surfaces prior to SDB(silicon wafer direct bonding). In this paper, we prepared silicon surfaces in several chemical solutions, and annealed bonding wafers which were combined with thermally oxidized wafers and bare silicon wafers in the temperature range of $600{\times}1000^{\circ}C$. After bonding, the bonding interface is investigated by an infrared(IR) topography system which uses the penetrability of infrared through silicon wafer. Using this procedure, we observed intrinsic bubbles at elevated temperatures. So, we verified that these bubbles are related to cleaning and drying conditions, and the interface oxides on silicon wafer reduce the formation of intrinsic bubbles.

• 대한전기학회:학술대회논문집
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• 대한전기학회 1999년도 하계학술대회 논문집 G
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• pp.3279-3281
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• 1999

This paper describes a method of direct wafer bonding using surfaces activated by a radio-frequency hydrogen plasma. The hydrogen plasma cleaning of silicon in the RIE mode was investigated as a pretreatment for silicon direct bonding. The cleaned silicon surface was successfully terminated by hydrogen, The hydrogen-terminated surfaces were rendered hydrophilic, which could be wetted by Dl water rinse. Two wafers of silicon and silicon dioxide were contacted to each other at room temperature and postannealed at $300{\sim}1100^{\circ}C$ in an $N_2$ atmosphere for 2 h. From the AFM results, it was revealed that the surface became rougher with the increased plasma exposure time and power. The effect of the plasma treatment on the surface chemistry was investigated by the AES analysis. It was shown that the carbon contamination at the surface could be reduced below 5 at %. The interfacial energy measured by the crack propagation method was 122 $mJ/m^2$ and 384 $mJ/m^2$ for RCA cleaning and hydrogen plasm, respectively.