• Proceedings of the KIEE Conference
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• 2007.07a
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• pp.1339-1340
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• 2007

본 연구에서는 이종 차원 나노선과 나노입자의 결합에 따른 단일 나노선 소자의 전기적 특성 및 메모리 효과를 연구하였다. 열증착법으로 성장 된 p 형 Si 나노선에 Atomic Layer Deposition (ALD) 방법으로 10nm의 $Al_{2}O_{3}$를 증착한 후 Low Precensure - Chemical Vapor Deposition (LP-CVD)를 이용하여 Polycrystalline Sicon(Poly-Si)을 Si 나노선 위에 5nm 증착하고 습식 에칭법을 이용하여 poly Si 내의 $SiO_x$를 제거하여 Si 나노입자를 Si 나노선 위에 형성시켰다. 그 후 포토리소그래피 공정을 이용하여 Top gate 형태의 나노선-나노입자 이종결합 Field-Effect Transistor (FET) 소자를 제작하여 게이트 전압에 따른 드레인 전류-전압($I_{DS}-V_{DS}$)의 변화를 측정하여 나노선의 전기 소자로서의 특성을 확인하고, 게이트 전압을 양방향으로 swing 하면서 인가하여 $I_{DS}$ 전류 특성이 변화하는 것을 통해 메모리 효과를 조사하였다. 또한 나노입자의 결합이 게이트 전압의 인가 시간에 따라 드레인 전류에 영향을 미치는 것을 확인하여 메모리 소자로서의 가능성을 확인하였다.

• Journal of the Korean Vacuum Society
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• v.17 no.5
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• pp.426-434
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• 2008

A space averaged $SiH_4/O_2/Ar$ simulator for the high density inductively coupled plasma sources for $SiH_4/O_2/Ar$ discharge is developed. The developed simulator uses space averaged fluid equations for electrons, positive ions, negative ions, neutral species, and radicals in $SiH_4/O_2/Ar$ plasma discharge, and the electron heating model including the anomalous skin effect. Using the developed simulator, the dependency of the density of charged particles, neutral particles, and radicals, the electron temperature, the plasma resistance, and the power absorption coefficient for the RF power and pressure is calculated.

• Journal of the Korean Vacuum Society
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• v.6 no.2
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• pp.159-164
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• 1997

We have studied initial oxidation of the alkali metal(AM)/Si(111) surface using X-ray photoelectron spectroscopy(XPS) and reflection high energy electron diffraction(RHEED) at room temperature(RT) and high temperature(HT)(300~50$0^{\circ}C$). The oxidation of the Si(111)7$\times$7 surface was promoted by the adsorption of 1 momolayer(ML) AM, whereas no promotion occurred for submonolayer(<0.5 ML) adsorbed Si(111)7$\times$7 surface at RT. O Is core level spectra were measured with increasing oxygen exposure. It was found that the oxygen adsorbed on the Si(111)7$\times$7-AM surface have two different bond configuration, Si-O and Am-O, respectively. From these results, we discussed the role of AM-O bonding in the promoted oxidation. At HT(300~50$0^{\circ}C$), the AM-adsorbed surface became very inactive with the structural transformation to the 3$\times$1-AM. We present the results of the oxidation of the Si(111)3$\times$1-AM(Na, K, Cs) surface.

• Journal of the Institute of Electronics Engineers of Korea SD
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• v.43 no.2 s.344
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• pp.13-17
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• 2006

Pentacene channel for organic thin film transistor was deposited on the SiOC film by thermal evaporation. The growth of pentacene is related with the Diels-Alder reaction and the nucleophilic reaction by the thermal induction. The surface is an important factor to control the recursive Diels-Alder reaction for growing of pentacene on SiOC far The terminal C=C double bond of pentacene molecule was broken easily as a result of attack of the nucleophilic reagents on the surface of SiOC film. The nucleophilic reaction can be accelerated by increasing temperature on surface, and it maks pentacene to grow hardly on the SiOC film with a flow rate ratio of $O_2/(BTMSM+O_2)=0.5$ due to its inorganic property. The nucleophlic reaction mechanism is $SN_2(bimolecular nucleophilic substitution)$ type.

• Proceedings of the Korean Vacuum Society Conference
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• 1999.07a
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• pp.105-105
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• 1999

차세대 기억소자에서는 집접도의 증가, 고속화, 그리고 미세화에 따라 배선간으 최소선폭이 작아지고, 새로운 다층 배선기술이 요구되는 가운데 층간절연막의 재료와 형성기술은 소자의 특성을 향상시켜주는 중요한 요소로서 열적안정성, 저유전율, 평탄화특성 등에 핵심을 두고 연구되고 있다. 본 연구에서는 5인치 p-Si(100) 위에 FTES와 O2를 precursor로 하고 carrier gas를 Ar gas하여 ICP CVD 방법으로 저유전율의 Fluorocarbonated-SiO2 박막을 형성하였다. 0.1-1kW, 13.56MHz인 rf power를 사용하였으며, 증착은 RT에서 5~10분으로 하였다. 형성된 박막은 FTIR(fourier transform infrared), XPS(x-ray photoelectron spectroscopy), 그리고 ellipsopsometer 등을 이용하여 결합모드와 F농도, 균일도 등을 측정하고, I-V와 C-V 측정장치, 그리고 SERM(scanning electrion microscopy) 등을 이용하여 유전상수, 누설전류, dielectric breakdown voltage, 그리고 박막의 stepcoverage를 측정하였다. 제작된 박막의 신뢰성은 열처리에 따른 전기적 특성으로부터 조사하였다. 형성된 fluorocarbonated 박막 결합모드는 Si-F, Si-O, O-C, C-C와 C-F였고 O2:FTES:Ar 유량을 1sccm:10sccm:6sccm으로 하여 증착한 시료에서 유전율은 2.8이었으며, 누설전류밀도는 8$\times$10-9A/cm2, Breakdown voltage는 10MV/cm 이상, 그리고 stepcoverage는 91%로 측정되었다.

• Korean Journal of Materials Research
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• v.8 no.9
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• pp.825-830
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• 1998

자화된 유도결합형 C4F8 플라즈마로 SiO2를 건식식각시 실리콘 표면에 발생하는 손상과 오염에 대하여 연구하였다. 오염의 분석을 위해서 XPS, SIMS, TEM을 사용하였으며, 손상정도를 측정하기 위해서 HRTEM과 Schottky-diode 구성을 통한 I-V특성 측정을 사용하였다. 유도 결합형 C4F8 플라스마에 0에서 18Gauss까지의 자장이 가해짐에 따라서 실리콘 표면에 생기는 잔류막의 두께가 SiO2식각속도와 선택비의 증가와 함께 증가하였으며, XPS를 통하여 그 조성이 fluorine-rich에서 carbon-rich 한 상태로 변화함을 알 수 있었다. 자장을 가하지 않는 상태에서는 표면에서 $40\AA$부근까지 고밀도의 손상층이 관찰되었으나, 자장을 가함에 따라서 노출된 손상층의 깊이는 깊어지나 그 밀도는 줄어들음을 HRTEM을 통하여 관찰 할 수 있었다. Schottky-diode를 통한 I-V특성곡선의 분석으로 자장이 증가함에 따라서 전기적인 손상이 감소함을 알 수 있었다.

• Journal of the Korean Chemical Society
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• v.43 no.2
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• pp.172-181
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• 1999

To develop the manufacturing technique for the powder builder of amorphous solid types, the water glass mixed with caustic soda dispersed into the methanol. Thus soluble sodium silicate was made a form of amorphous solid powder. In order to examine characteristics of water soluble sodium silicate $SiO_2/Na_2O$ mol ratio, we investigated solubility, thermogram, SEM, and BET analysis. pH buffering capacity, calcium-ion binding capacity as temperature change, and surfactant loading capacity were examined for characteristics as laundry detergent builder. $SiO_2/Na_2O$ molar ratio of soluble sodium silicate was 1.0, 2.4, 2.8, and zeolite was used in order to investigate basic characteristics of laundry detergent builder. Silicate used with laundry detergent was good for pH buffering capacity and solubility. But calcium-ion binding capacity and surfactant adsorption ability were lower. $SiO_2/Na_2O$ mol ratio became higher, pH buffering capacity and ion exchange ability were lower and surfactant adsorption ability was a little higher.

• Journal of the Korean Ceramic Society
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• v.29 no.11
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• pp.837-842
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• 1992

SiC and Si mixtures dispersed by 0.5~10.0 wt% of Al2O3 and reinforced by SiC whisker were sintered to Si3N4 bonded SiC bodies at 140$0^{\circ}C$ in a N2 gas atmosphere, and the nitridation and mechanical properties of sintered bodies were investigated. From these observation, it is concluded that relative density and bending strength increased with the rising of nitridation and the highest nitridation ratio was obtained for a specimen having 1.5 wt% Al2O3. On the other hand, the amount of $\beta$-Si3N4 in the specimens containing Al2O3 more than 5.0 wt% was increased abruptly and the best in fracture toughness was sintered for a composits having 30 wt% SiC whiskers.

• Journal of Sensor Science and Technology
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• v.7 no.3
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• pp.147-153
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• 1998

The strain characteristics of a fiber optic Fabry-Perot pressure sensor with high sensitivity using a $Si_{3}N_{4}/SiO_{2}/Si_{3}N_{4}$ (N/O/N) diaphragm is experimentally investigated. A 600 nm thick N/O/N diaphragm was fabricated by silicon anisotropic etching technology in 44 wt% KOH solution. An interferometric fiber optic pressure sensor has been manufactured by using a fiber optic Fabry-Perot intereferometer and a N/O/N diaphragm. The 2 cm length fiber optic Fabry-Perot interferometers in the continuous length of single mode fiber were produced with two pieces of single mode fiber coated with $TiO_{2}$ dielectric film utilizing the fusion splicing technique. The one end of the fiber optic Fabry-Perot interferometer was bonded to a N/O/N diaphragm. and the other end was connected to an optical setup through a 3 dB coupler. For the N/O/N diaphragm sized $2{\times}2\;mm^{2}$ and $8{\times}8\;mm^{2}$, the pressure sensitivity was measured 0.11 rad/kPa and 1.57 rad/kPa, respectively, and both of the nonlinearities were less than 0.2% FS.

• Journal of the Mineralogical Society of Korea
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• v.19 no.4 s.50
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• pp.347-353
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• 2006

The atomic-nano scale structures of multi-component aluminosilicate glasses have not been well understood in spite of its implications fur dynamics and generation of magma in the natural system due to lack of suitable spectroscopic and scattering experiments. Here, we report O-17 MAS and isotropic projection of 3QMAS NMR spectra for quaternary Na-Ca silicate glasses $[(CaO)_x(Na_2O)_{1-x}]\;(A1_2O_3)_{0.5}(SiO_2)_6,\;CNAS)$ at 14.1 Tesla where atomic configurations around bridging oxygen (Si-O-Si, Si-O-Al) and non bridging oxygen (Na-O-Si, Ca-O-Si, (Na, Ca)-O-Si) are partially resolved. With increasing Na content, the fraction of Na-O-Si increases while those for bridging oxygens remain constant. The Na/Ca ratio apparently affects the peak widths of bridging oxygen peaks (e.g., Si-O-Si)) and thus the topological entropy as well as chemical shifts of the bridging oxygen peaks, implying that both BOs and NBOs are strongly interacting with network modifying cations The effect of cation field strength on the degree of Al-avoidance was also discussed.