화학기상응축법을 이용한 Si-C-N Precursor 분말의 합성 및 특성평가

김형인,김대정,홍진석,소명기,Kim, Hyoung-In,Kim, Dae-Jung,Hong, Jin-Seok,So, Myoung-Gi 한국세라믹학회 2002 한국세라믹학회지 Vol.39 No.8

In this study, nano-sized Si-C-N precursor powders were synthesized by Chemical Vapor Condensation Method(CVC) using TMS(Tetramethylsilane: Si($CH_3)_4$), $NH_3$ and $H_2$ gases under the various reaction conditions of the reaction temperature, TMS/$NH_3$ ratio and TMS/$H_2$ ratio. XRD and FESEM were used to analysis the crystalline phase and the average particle size of the synthesized powders. It was found that the obtained powders under the considering conditions were all spherical amorphous powder with the particle size of 87∼130 nm. The particle size was decreased as the reaction temperature increased and TMS/$NH_3$ and TMS/$H_2$ ratio decreased. As the results of EA analysis, it was found that the synthesized powders had been formed the powders composed of Si, N, C and H. Through FT-IR results, it was found that the synthesized powders were Si-C-N precursor powders with Si-C, Si-N and C-N bonds. 본 연구에서는 TMS[Tetramethylsilane:Si($CH_3)_4$], $NH_3$와 $H_2$를 이용하여 나노크기의 Si-C-N precursor 분말을 합성하기 위하여 CVC법을 이용하였으며 반응온도, TMS/$NH_3$ 비 그리고 TMS/$H_2$ 비를 변화시켰다. XRD와 FESEM 분석을 통해서 결정상과 입자의 크기 그리고 입자의 형태를 관찰하고자 하였으며, 그 결과 제조된 분말은 모든 실험 조건하에서 87∼130 nm 크기를 지닌 균일한 구형의 비정질 분말이 얻어졌다. 입자 크기는 반응온도의 감소에 따라 감소하였으며, 또한 TMS/$NH_3$, TMS/$H_2$ 비가 작아질수록 감소하였다. EA 분석 결과 제조된 분말은 Si, N, C, H로 이루어졌음을 알 수 있었으며 FT-IR를 통하여 Si-N, C-N, Si-C 결합을 가진 Si-C-N precursor 분말이 제조되었다

하이브리드 코팅시스템에 의해 제조된 Cr-Mo-Si-C-N 박막의 미세구조 및 기계적 특성연구

윤지환(Ji Hwan Yun),안성규(Sung Kyu Ahn),김광호(Kwang Ho Kim) 한국표면공학회 2007 한국표면공학회지 Vol.40 No.6

Cr-Mo-Si-C-N coatings were deposited on steel and Si wafer by a hybrid system of AIP and sputtering techniques using Cr, Mo and Si target in Ar/N₂/CH₄ gaseous mixture. Instrumental analyses of XRD and XPS revealed that the Cr-Mo-Si-C-N coatings must be a composite consisting of fine (Cr, Mo and Si)(C and N) crystallites and amorphous Si₃N₄ and SiC. The hardness value of Cr-Mo-Si-C-N coatings significantly increased from 41 GPa of Cr-Mo-C-N coatings to about 53 GPa with Si content of 9.3 at.% due to the refinement of (Cr, Mo and Si)(C and N) crystallites and the composite microstructure characteristics. A systematic investigation of the microstructures and mechanical properties of Cr-Mo-Si-C-N coatings prepared with various Si contents is reported in this paper.

하이브리드 코팅 시스템으로 제조된 초고경도 Cr-Si-C-N 나노복합 코팅막의 미세구조 및 기계적 특성

장철식(Chul Sik Jang),허수정(Su Jeong Heo),송풍근(Pung Keun Song),김광호(Kwang Ho Kim) 한국표면공학회 2005 한국표면공학회지 Vol.38 No.3

Cr-Si-C-N coatings were deposited on steel substrate (SKD11) by a bybrid system of arc ion plating (AIP) and sputtering techniques. From XRD, XPS, and HRTEM analyses, it was found that Cr-Si-C-N had a fine composite microstructure comprising nano-sized crystallites of Cr(C,N) well distributed in the amorphous phase of Si₃N₄/SiC mixture. Microhardness of Cr(C,N) coatings and Cr-Si-N coatings were reported about ~22 ㎬ and -35 ㎬, respectively. As the Si was incorporated into Cr(C,N) coatings, The Cr-Si-C-N coatings having a Si content of 9.2 at. % showed the maximum hardness value. As increased beyond Si content of 9.2 at. %, the interaction between nanocrystallites and amorphous phase was gone, the hardness was reduced as dependent on amorphous phase of Si₃N₄/SiC. In addition, the average coefficient of Cr-Si-C-N coatings largely decreased compared with Cr(C,N) coatings.

Selective Etching of Thick Si3N4, SiO2 and Si by Using CF4/O2 and C2F6 Gases with or without O2 or Ar Addition

이희관,정관수,유재수 한국물리학회 2009 THE JOURNAL OF THE KOREAN PHYSICAL SOCIETY Vol.54 No.5

The etching characteristics of thick Si3N4, SiO2 and Si in CF4/O2 (95 %/5 %) and C2F6 plasmas with or without O2 or Ar gas as diluents by using reactive ion etching were studied, together with photoresist mask erosion rate during the etching. Etching parameters, such as the CF4/O2 (or C2F6) flow rate, the O2 flow rate, the Ar flow rate, the rf power and the process pressure, were changed. The selective etching of Si3N4 over SiO2 and Si was also investigated under various etching conditions. We found that CF4/O2 gas was more efficient than C2F6 gas owing to the enhanced Si3N4 etching caused by NO for the selective etching of Si3N4 over both SiO2 and Si. In a CF4/O2 plasma, the etching selectivity was considerably improved with decreasing flow rates of CF4/O2 and O2 (or Ar) and with increasing process pressure. Si3N4 etch selectivities over SiO2 and Si of 13.2 and 8.9 were obtained, respectively, with 20 sccm CF4/O2 at 150 mTorr and 75 W, while maintaining a high Si3N4 etch rate of 306 nm/min. The etching rates were measured by using a surface profiler and a scanning electron microscope (SEM). The etched profiles and the surface morphology were observed by using a SEM. A possible mechanism for these etching phenomena is discussed. The etching characteristics of thick Si3N4, SiO2 and Si in CF4/O2 (95 %/5 %) and C2F6 plasmas with or without O2 or Ar gas as diluents by using reactive ion etching were studied, together with photoresist mask erosion rate during the etching. Etching parameters, such as the CF4/O2 (or C2F6) flow rate, the O2 flow rate, the Ar flow rate, the rf power and the process pressure, were changed. The selective etching of Si3N4 over SiO2 and Si was also investigated under various etching conditions. We found that CF4/O2 gas was more efficient than C2F6 gas owing to the enhanced Si3N4 etching caused by NO for the selective etching of Si3N4 over both SiO2 and Si. In a CF4/O2 plasma, the etching selectivity was considerably improved with decreasing flow rates of CF4/O2 and O2 (or Ar) and with increasing process pressure. Si3N4 etch selectivities over SiO2 and Si of 13.2 and 8.9 were obtained, respectively, with 20 sccm CF4/O2 at 150 mTorr and 75 W, while maintaining a high Si3N4 etch rate of 306 nm/min. The etching rates were measured by using a surface profiler and a scanning electron microscope (SEM). The etched profiles and the surface morphology were observed by using a SEM. A possible mechanism for these etching phenomena is discussed.

Thermal properties of Si-N/Si-C coated carbon fiber/polypropylene matrix composites

김현혜,이해성,한웅,김병주 한국공업화학회 2014 한국공업화학회 연구논문 초록집 Vol.2014 No.1

In this work, thermal properties of silicon nitride coated carbon fibers (CFs) reinforced polypropylene(PP) composites were investigated. The CFs was treated by silane. After that, the CFs was exposed under NH₃ / N₂ mixed atmosphere at 1400°C - 1600°C. The surface properties of CFs were analyzed using SEM, EDX, XRD and FT-IR. The thermal properties of composites and Si-N or Si-C coated CFs were measured by thermal conductivity meter and TGA. As the result, the thermal properties of Si-N or Si-C coated CFs/PP composites improved better than uncoated CFs/PP composites. The Si-N or Si-C provided high thermal conductivity and stability to carbon fibers or composites.

C<SUB>fiber</SUB>/Si₃N₄ 복합재료의 내마모 특성

이영주(Young-Ju Lee),김성훈(Seong-Hoon Kim),윤한기(Han-Ki Yoon),김부안(Bu-Ahn Kim) 대한기계학회 2006 대한기계학회 춘추학술대회 Vol.2006 No.11

The abrasion decides the life of the C<SUB>fiber</SUB>/Si₃N₄ composite is very important factor. particularly, The Si₃N₄ ceramics and advanced materials are variously studied as the abrasion resistance materials in severe environments. Because they are have excellent value such as high temperature strength, hardness, chemical stability better than metal and polymer materials. But the abrasion resistance of Si₃N₄ composite various carbon fiber rate is not studied. In this paper, the abrasion resistance characteristic of C<SUB>fiber</SUB>/Si₃N₄ composites. Also, the frictional coefficient and the abrasion mechanism characteristics were investigated about variety both applied load and temperature.

Characterization of tunnel oxide passivated contact with n-type poly-Si on ptype c-Si wafer substrate

Xueqi Guo,Yuheng Zeng,Zhi Zhang,Yuqing Huang,Mingdun Liao,Qing Yang,Zhixue Wang,Minyong Du,Denggao Guan,Baojie Yan,Jichun Ye 한국물리학회 2019 Current Applied Physics Vol.19 No.7

The junction properties of tunnel silicon oxide (SiOx) passivated contact (TOPCon) with n-type poly-Si on p-type c-Si wafer are characterized using current-voltage (J-V) and capacitance-voltage (C-V) measurements. The dark J-V curves show a standard diode characteristic with a turn-on voltage of ∼0.63 V, indicating a p-n junction is formed. While the C-V curve displays an irregular shape with features of 1) a slow C increase with the decrease of the magnitude of reverse bias voltage, being used to estimate the built-in potential (Vbi), 2) a significant increase at a given positive bias voltage, corresponding to the geometric capacitance crossing the ultrathin SiOx, and 3) a sharp decrease to negative values, resulting from the charge tunneling through the SiOx layer. The C of depleting layer deviates from the normal linear curve in the 1/C2-V plot, which is caused by the diffusion of P dopants from the n-type poly-Si into the p-type c-Si wafer as confirmed by the electrochemical capacitance-voltage measurements. However, the 1/C2+γ-V plots with γ > 0 leads to linear curves with a proper γ and the Vbi can still be estimated. We find that the Vbi is the range of 0.75–0.85 V, increases with the increase of the doping ratio during the poly-Si fabrication process, and correlates with the passivation quality as measured by the reverse saturated current and implied open circuit voltage extracted from transient photoconductivity decay.

Preparation and characterization of silicon nitride (SiN)-coated carbon fibers

김현혜,한웅,이해성,김병주 한국공업화학회 2015 한국공업화학회 연구논문 초록집 Vol.2015 No.1

In this study, the characteristics of silicon nitride (SiN) coated on the carbon fibers by wet-thermal treatments were investigated. The organic precursor, 3-aminopropyltriethoxysilane (APS), was used as a source for ‘Si’ of SiN ceramic coating on the carbon fibers. And the NH₃/N₂ mix gas was used as source for ‘N’. The chemical and microstructural properties of SiN coated on carbon fiber surfaces were analysis using XRD, EDS, XPS, SEM, and TEM. Surface functionalization was quantified by EDS and XPS analysis; these compared the ratio of Si, C and N content in the coating. From the TEM analysis demonstrated that the coatings were composed of crystalline Si-C-N along with Si-N. From the XRD results, it was conjectured that the crystallite size of Si-C-N increased with increasing Si, C and N contents.

A Novel Method to Improve the Dispersibility of Silicon Nitride Powders in Aqueous Media

Bingjie Xu,Mengxing Li,Qi Chen,Pengfei Liu,Baosong Xu,Ben Qiu,Liang Xu,Zhao Han 성균관대학교(자연과학캠퍼스) 성균나노과학기술원 2019 NANO Vol.14 No.9

The present study describes a novel method to improve the dispersibility of silicon nitride powders in aqueous media. Specifically, a new Si3N4@g-C3N4 core–shell composite material was synthesized via annealing the mixture of silicon nitride and melamine under a nitrogen atmosphere using heating method. The effects of various initial mass ratios of Si3N4 and melamine on the structure and dispersibility of the composite were systematically investigated. The results of X-ray photoelectron spectroscopy and transmission electron microscope demonstrated that as-obtained Si3N4@g-C3N4 composite powders possess the core–shell structure, whereas the zeta potential and sedimentation analysis showed that they exhibit good dispersion in aqueous media. Furthermore, the colloidal dispersion of the composite powders is most stable when the initial mass ratio of Si3N4 and melamine is 100 : 3. The coated g-C3N4 could be completely removed in a cryogenic nitrogen atmosphere. The proposed process is expected to provide novel avenues for the study of dispersion of other inorganic powders.

SiO$_2$/Si$_3$N$_4$ 이중 박막의 C-V 특성

Hong, Nung-Pyo,Hong, Jin-Woong The Korean Institute of Electrical Engineers 2003 전기학회논문지C Vol.52 No.10

The double layers of $SiO_2$/$Si_3$$N_4$ have superior charge storage stability than a single layer of $SiO_2$. Many researchers are very interested in the charge storage mechanism of $SiO_2$/$Si_3$$N_4$ [1,2]. In this paper, the electrical characteristics of thermal oxide and atmospheric pressure chemical vapor deposition (APCVD) of $Si_4$$N_4$ have been investigated and explained using high frequency capacitance-voltage measurements. Additionally, this paper will describe capacitance-voltage characteristics for double layers of $SiO_2$/$Si_4$$N_4$ by "Athena", a semiconductor device simulation tool created by Silvaco, Inc.vaco, Inc.