Kinetic and gas-phase study of the chemical vapor deposition of silicon carbide from C2H3SiCl3/H2

A. Desenfant,G. Laduye,G.L. Vignoles,G. Chollon 한국공업화학회 2021 Journal of Industrial and Engineering Chemistry Vol.94 No.-

The chemical vapor deposition (CVD) of silicon carbide from vinyltrichlorosilane (VTS) was studied toidentify a range of conditions leading to pure crystalline SiC. The deposition rate was recorded toevidence the various deposition regimes. Gas phase, elemental analyses and infiltration tests were alsoperformed. Three distinct chemical reaction regimes were identified. In CVD conditions, carbon is codepositedat low temperature while VTS is only partially decomposed. In infiltration conditions, thecomposition switches to pure SiC inside the porous substrate because of a depletion of reactivehydrocarbon species. Competing heterogeneous reactions are responsible for a hysteresis versustemperature, in both deposition rate and composition of the deposit. The high temperature domain is themost suitable to deposit pure crystalline SiC in CVD conditions. Hydrogen dilution strongly acceleratesthe homogeneous decomposition of VTS as compared to argon. Assumptions on the reaction mechanismwere proposed describing the chemistry of this precursor.

Polyimide 기판을 이용한 CVD-Cu 박막 형성기술

조남인,임종설,설용태 한국산학기술학회 2000 한국산학기술학회논문지 Vol.1 No.1

유기금속 화학기상중착기술에 의해 폴리이미드 가판과 질화티탄 기판 위에 구라박막을 형성하였다. 그리박막을 화학기상 증착기술에 의해 형성하면 종래의 물리적증착기술에 비하여 증적속도가 빠르고 층덮힘 성질이 좋아 산업체의 제품생산 응용에서 많은 장점이 있다. 이 장점은 제품의 생산성과 신뢰성에 영향을 마친다. 기판의 온도와 구리전구체 증기압력 조건을 변화시키며 반복실험을 실시하였으며, 시편에 따라서는 전기적 성질 향상을 위하여 후속 열처리를 수행하였다. 형성된 구리박막의 미세구조는 전자현미경으로 관찰하였으며 전기비저항은 4점 프로브를 이용하여 즉정하였다 질화티탄을 기판으로 사용한 경우 구리박막 에서는 섭씨 180도의 기판온도에서 만들어진 시편에서 가장 좋은 전기적 성질이 측정되었다. 한편 폴리이미드 기판을 사용한 경우, 기상과 액상의 혼합상태 전구체를 이용하여 250 ㎚/min의 매우 높은 증착속도를 얻을 수 있었다. Copper thin films have been prepared by a metal organic chemical vapor deposition (MOCVD) technology on polyimide and TiN substrates. The Cu-MOCVD technology has advantages of the high deposition rate and the good step coverage compared with the conventional physical vapor deposition (PVD) technology in several industrial applications. The Cu films have been deposited with varying the experimental conditions of substrate temperatures and copper source vapor pressures. The films were annealed in a vacuum condition after the deposition. and the annealing effect on the electrical properties of the films was measured. The crystallinity and the microstructures of the films were observed by scanning electron microscopy (SEM). and tho electrical resistivity was measured by 4-point probe. ln the case of the Cu deposition on TiN substrate. the best electrical property of the films was measured for the samples prepared at 180 ℃. Very high deposition rate of the Cu film up to 250 ㎚/min was obtained on the polyimide substrate when the mixture of liquid and vapour precursor was used.

Culturing of Rat Intestinal Epithelial Cells-18 on Plasma Polymerized Ethylenediamine Films Deposited by Plasma Enhanced Chemical Vapor Deposition

Choi, Chang-Rok,Kim, Kyung-Seop,Kim, Hong-Ja,Park, Heon-Yong,Jung, Dong-Geun,Boo, Jin-Hyo Korean Chemical Society 2009 Bulletin of the Korean Chemical Society Vol.30 No.6

Many researchers studied cell culturing on surfaces with chemical functional groups. Previously, we reported surface properties of plasma polymerized ethylenediamine (PPEDA) films deposited by plasma enhanced chemical vapor deposition with various plasma conditions. Surface properties of PPEDA films can be controlled by plasma power during deposition. In this work, to analyze correlation of cell adherence/proliferation with surface property, we cultured rat intestinal epithelial cells-18 on the PPEDA films deposited with various plasma powers. It was shown that as plasma power was decreased, density of cells cultured on the PPEDA film surface was increased. Our findings indicate that plasma power changed the amine density of the PPEDA film surface, resulting in density change of cells cultured on the PPEDA film surface.

Initiated Chemical Vapor Deposition (iCVD) of Highly Cross<i>-</i>Linked Polymer Films for Advanced Lithium-Ion Battery Separators

Yoo, Youngmin,Kim, Byung Gon,Pak, Kwanyong,Han, Sung Jae,Song, Heon-Sik,Choi, Jang Wook,Im, Sung Gap American Chemical Society 2015 ACS APPLIED MATERIALS & INTERFACES Vol.7 No.33

<P>We report an initiated chemical vapor deposition (iCVD) process to coat polyethylene (PE) separators in Li-ion batteries with a highly cross-linked, mechanically strong polymer, namely, polyhexavinyldisiloxane (pHVDS). The highly cross-linked but ultrathin pHVDS films can only be obtained by a vapor-phase process, because the pHVDS is insoluble in most solvents and thus infeasible with conventional solution-based methods. Moreover, even after the pHVDS coating, the initial porous structure of the separator is well preserved owing to the conformal vapor-phase deposition. The coating thickness is delicately controlled by deposition time to the level that the pore size decreases to below 7% compared to the original dimension. The pHVDS-coated PE shows substantially improved thermal stability and electrolyte wettability. After incubation at 140 °C for 30 min, the pHVDS-coated PE causes only a 12% areal shrinkage (versus 90% of the pristine separator). The superior wettability results in increased electrolyte uptake and ionic conductivity, leading to significantly improved rate performance. The current approach is applicable to a wide range of porous polymeric separators that suffer from thermal shrinkage and poor electrolyte wetting.</P><P><B>Graphic Abstract</B> <IMG SRC='http://pubs.acs.org/appl/literatum/publisher/achs/journals/content/aamick/2015/aamick.2015.7.issue-33/acsami.5b05720/production/images/medium/am-2015-05720m_0008.gif'></P><P><A href='http://pubs.acs.org/doi/suppl/10.1021/am5b05720'>ACS Electronic Supporting Info</A></P>

Synthesis and Characterization of Carbon nanofibers on Co and Cu Catalysts by Chemical Vapor Deposition

Park, Eun-Sil,Kim, Jong-Won,Lee, Chang-Seop Korean Chemical Society 2014 Bulletin of the Korean Chemical Society Vol.35 No.6

This study reports on the synthesis of carbon nanofibers via chemical vapor deposition using Co and Cu as catalysts. In order to investigate the suitability of their catalytic activity for the growth of nanofibers, we prepared catalysts for the synthesis of carbon nanofibers with Cobalt nitrate and Copper nitrate, and found the optimum concentration of each respective catalyst. Then we made them react with Aluminum nitrate and Ammonium Molybdate to form precipitates. The precipitates were dried at a temperature of $110^{\circ}C$ in order to be prepared into catalyst powder. The catalyst was sparsely and thinly spread on a quartz tube boat to grow carbon nanofibers via thermal chemical vapor deposition. The characteristics of the synthesized carbon nanofibers were analyzed through SEM, EDS, XRD, Raman, XPS, and TG/DTA, and the specific surface area was measured via BET. Consequently, the characteristics of the synthesized carbon nanofibers were greatly influenced by the concentration ratio of metal catalysts. In particular, uniform carbon nanofibers of 27 nm in diameter grew when the concentration ratio of Co and Cu was 6:4 at $700^{\circ}C$ of calcination temperature; carbon nanofibers synthesized under such conditions showed the best crystallizability, compared to carbon nanofibers synthesized with metal catalysts under different concentration ratios, and revealed 1.26 high amorphicity as well as $292m^2g^{-1}$ high specific surface area.

Flexible, Low-Power Thin-Film Transistors Made of Vapor-Phase Synthesized High-<i>k</i>, Ultrathin Polymer Gate Dielectrics

Choi, Junhwan,Joo, Munkyu,Seong, Hyejeong,Pak, Kwanyong,Park, Hongkeun,Park, Chan Woo,Im, Sung Gap American Chemical Society 2017 ACS APPLIED MATERIALS & INTERFACES Vol.9 No.24

<P>A series of high-k, ultrathin copolymer gate dielectrics were synthesized from 2-cyanoethyl acrylate (CEA) and di(ethylene glycol) divinyl ether (DEGDVE) monomers by a free radical polymerization via a one-step, vapor-phase, initiated chemical vapor deposition (iCVD) method. The chemical composition of the copolymers was systematically optimized by tuning the input ratio of the vaporized CEA and DEGDVE monomers to achieve a high dielectric constant (k) as well as excellent dielectric strength. Interestingly, DEGDVE was nonhomopolymerizable but it was able to form a copolymer with other kinds of monomers. Utilizing this interesting property of the DEGDVE cross-linker, the dielectric constant of the copolymer film could be maximized with minimum incorporation of the cross-linker moiety. To our knowledge, this is the first report on the synthesis of a cyanide-containing polymer in the vapor phase, where a high-purity polymer film with a maximized dielectric constant was achieved. The dielectric film with the optimized composition showed a dielectric constant greater than 6 and extremely low leakage current densities (< 3 X 10(-8) A/cm(2) in the range of +/- 2 MV/cm), with a thickness of only 20 nm, which is an outstanding thickness for down-scalable cyanide polymer dielectrics. With this high-k dielectric layer, organic thin-film transistors (OTFTs) and oxide TFTs were fabricated, which showed hysteresis-free transfer characteristics with an operating voltage of less than 3 V. Furthermore, the flexible OTFTs retained their low gate leakage current and ideal TFT characteristics even under 2% applied tensile strain, which makes them some of the most flexible OTFTs reported to date. We believe that these ultrathin, high-k organic dielectric films with excellent mechanical flexibility will play a crucial role in future soft electronics.</P>

Metal Organic Chemical Vapor Deposition법을 이용한 Germanium 전구체의 증착 특성 연구

김선희,김봉준,김도형,이준기,Kim, Sun-Hee,Kim, Bong-June,Kim, Do-Heyoung,Lee, June-Key 한국재료학회 2008 한국재료학회지 Vol.18 No.6

Polycrystalline germanium (Ge) thin films were grown by metal organic chemical vapor deposition (MOCVD) using tetra-allyl germanium [$Ge(allyl)_4$], and germane ($GeH_4$) as precursors. Ge thin films were grown on a $TiN(50nm)/SiO_2/Si$ substrate by varying the growth conditions of the reactive gas ($H_2$), temperature ($300-700^{\circ}C$) and pressure (1-760Torr). $H_2$ gas helps to remove carbon from Ge film for a $Ge(allyl)_4$ precursor but not for a $GeH_4$ precursor. $Ge(allyl)_4$ exhibits island growth (VW mode) characteristics under conditions of 760Torr at $400-700^{\circ}C$, whereas $GeH_4$ shows a layer growth pattern (FM mode) under conditions of 5Torr at $400-700^{\circ}C$. The activation energies of the two precursors under optimized deposition conditions were 13.4 KJ/mol and 31.0 KJ/mol, respectively.

Synthesis of graphene on various copper foils by chemical vapor deposition

Yena Kim 한양대학교 세라믹연구소 2014 Journal of Ceramic Processing Research Vol.15 No.4

Recently, mono-layer and few layer graphene films grown by chemical vapor deposition (CVD) using metal substrate as a catalyst have attracted tremendous attention for the last few years. Copper (Cu) has been extensively used as a growth catalytic substrate due to its very low carbon solubility, which is thought to be responsible for the self-limiting precipitation growth and surface decomposition of carbon-containing molecules. Graphene films were synthesized on two types of catalytic substrates, electro-plating and rolling Cu foil, by chemical vapor deposition. Graphene film grown on various Cu foils was analyzed by Raman spectroscopy and scanning electron microscopy (SEM), with the aim of assessing their characteristics and finding the optimum catalyst conditions.

Effects of cobalt and cobalt oxide buffer layers on nucleation and growth of hot filament chemical vapor deposition diamond films on silicon (100)

Mushtaq Ahmad Dar,Hatem Abuhimd,Iftikhar Ahmad,Mohammad Islam,Mohammad Rezaul Karim,Hyung-Shik Shin 한국화학공학회 2014 Korean Journal of Chemical Engineering Vol.31 No.7

An initial study on the nucleation and growth of diamond, using hot filament chemical vapor deposition(HFCVD) technique, was carried out on Co and CoO thin buffer layers on non-carbon substrates (Si (100)), and theresults were compared with conventional scratching method. The substrate temperature during the growth was maintainedat 750±50 oC. A mixture of CH4 and H2 (1 : 100 volume %) was used for deposition. The total pressure duringthe two hour deposition was 30±2 Torr. X-ray photoelectron spectroscopy (XPS) study showed the diamond nucleationat different time periods on the Co and CoO seed layers. It is observed that Co helps in nucleation of diamond eventhough it is known to degrade the quality of diamond film on W-C substrate. The reason for improvement in our studyis attributed to (i) the low content of Co (~0.01%) compared to W-C substrate (~5-6%), (ii) formation of CoSi2 phaseat elevated temperature, which might work as nucleation sites for diamond. SEM analysis reveals a change in the morphologyof diamond film grown on cobalt oxide and a significant reduction in the size of densely packed crystallites. Raman spectroscopic analysis further suggests an improvement in the quality of the film grown on CoO buffer layer.

Computational study on the decomposition of tetraneopentyl zirconium for the chemical vapor deposition of zirconium carbide

원용선 한국화학공학회 2012 Korean Journal of Chemical Engineering Vol.29 No.10

The overall gas phase decomposition mechanism of tetraenopentyl zirconium precursor (Zr[CH2C(CH3)3]4)for the chemical vapor deposition of zirconium carbide thin films was investigated by using computational thermochemistry. Density functional theory (DFT) and harmonic vibrational frequency calculation were used to generate thermodynamic properties at each reaction step, based on which thermodynamic or kinetic preference of a reaction pathway was evaluated. While the preference of γ-hydrogen abstraction of neopentane over α-hydrogen abstraction was confirmed in the initial stage of ZrNp4 decomposition, they turned out to be competing instead of the dominant preference of γ-hydrogen abstraction. Methane formation at three subsequent reaction steps was explained by β-methyl migration, and the following α-hydrogen abstraction of methane based on the suggestion that α- and γ-hydrogen abstractions of neopentane are competing kinetically in previous reaction steps. Computational thermochemistry showed a possibility as a general tool to anticipate the gas phase decomposition mechanism of a precursor in chemical vapor deposition.