• Title/Summary/Keyword: SiOCH

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Photoaddition Reactions of N-Methylthiophthalimide with $\alpha$-Silyl-n-electron Donors via Single Electron Transfer-Desilylation and Hydrogen Atom Abstraction Pathways

  • Yoon, Ung-Chan;Oh, Sun-Wha;Moon, Seong-Chul;Hyung, Tae-Gyung
    • Journal of Photoscience
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    • v.9 no.1
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    • pp.17-22
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    • 2002
  • Studies have been conducted to explore photoaddition reactions of N-methylthiophthalimide with $\alpha$-silyl-n-electron donors Et$_2$NCH$_2$SiMe$_3$, n-PrSCH$_2$SiMe$_3$ and EtOCH$_2$SiMe$_3$. Photoaddition of $\alpha$-silyl amine Et$_2$NCH$_2$SiMe$_3$ to N-methylthiophthalimide occurs in $CH_3$CN and benzene to produce non-silicon containing adduct in which thiophthalimide thione carbon is bonded to $\alpha$-carbon of $\alpha$-silyl amine in place of the trimethylsilyl group. In contrast, photoaddition of EtOCH$_2$SiMe$_3$ to N-methylthiophthalimide generates two diastereomeric adducts in which thiophthalimide thione carbon is connected to $\alpha$-carbon of $\alpha$-silyl ether in place of u-hydrogen. Based on a consideration of the oxidation potentials of u-silyl-n-electron donors and the nature of photoadducts, mechanism for these photoadditions involving single electron transfer(SET) -desilylation and H atom abstraction pathways are proposed.

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Advanced Low-k Materials for Cu/Low-k Chips

  • Choi, Chi-Kyu
    • Proceedings of the Korean Vacuum Society Conference
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    • 2012.02a
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    • pp.71-71
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    • 2012
  • As the critical dimensions of integrated circuits are scaled down, the line width and spacing between the metal interconnects are made smaller. The dielectric film used as insulation between the metal lines contributes to the resistance-capacitance (RC) time constant that governs the device speed. If the RC time delay, cross talk and lowering the power dissipation are to be reduced, the intermetal dielectric (IMD) films should have a low dielectric constant. The introduction of Cu and low-k dielectrics has incrementally improved the situation as compared to the conventional $Al/SiO_2$ technology by reducing both the resistivity and the capacitance between interconnects. Some of the potential candidate materials to be used as an ILD are organic and inorganic precursors such as hydrogensilsequioxane (HSQ), silsesquioxane (SSQ), methylsilsisequioxane (MSQ) and carbon doped silicon oxide (SiOCH), It has been shown that organic functional groups can dramatically decrease dielectric constant by increasing the free volume of films. Recently, various inorganic precursors have been used to prepare the SiOCH films. The k value of the material depends on the number of $CH_3$ groups built into the structure since they lower both polarity and density of the material by steric hindrance, which the replacement of Si-O bonds with Si-$CH_3$ (methyl group) bonds causes bulk porosity due to the formation of nano-sized voids within the silicon oxide matrix. In this talk, we will be introduce some properties of SiOC(-H) thin films deposited with the dimethyldimethoxysilane (DMDMS: $C_4H_{12}O_2Si$) and oxygen as precursors by using plasma-enhanced chemical vapor deposition with and without ultraviolet (UV) irradiation.

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Chemical structure evolution of low dielectric constant SiOCH films during plasma enhanced plasma chemical vapor deposition and post-annealing procedures

  • Xu, Jun;Choi, Chi-Kyu
    • Proceedings of the Korean Society Of Semiconductor Equipment Technology
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    • 2002.11a
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    • pp.34-46
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    • 2002
  • Si-O-C-H films with a low dielectric constant were deposited on a p-type Si(100) substrate using a mixture gases of the bis-trimethylsilyl-methane (BTMSM) and oxygen by an inductively coupled plasma chemical vapor deposition (ICPCYD). High density plasma of about $~10^{12}\textrm{cm}^{-3}$ is obtained at low pressure (<400 mTorr) with rf power of about 300W in ICPCVD where the BTMSM and $O_2$ gases are fully dissociated. Fourier transform infrared (FTIR) spectra and X-ray photoelectron spectroscopy (XPS) spectra show that the film has $Si-CH_3$ and OH-related bonds. The void within films is formed due to $Si-CH_3$ and OH-related bonds after annealing at $500^{\circ}C$ for the as-deposition samples. The lowest relative dielectric constant of annealed film at $500^{\circ}C$ is about 2.1.

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Photopolymerization of Methyl Methacrylate with p-X-$C_{6}H_{4}SiH_{3}$ (X = F, $CH_3$, $OCH_3$)

  • U, Hui Gwon;Kim, Bo Hye;Jo, Myeong Sik;Kim, Dae Yeong;Choe, Yeong Seop;Gwak, Yeong Chae;Ham, Hui Seok;Kim, Dong Pyo;Hwang, Taek Seong
    • Bulletin of the Korean Chemical Society
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    • v.22 no.12
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    • pp.1337-1340
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    • 2001
  • The bulk photopolymerization of methyl methacrylate (MMA) with para-substituted phenylsilanes such as F-C6H4SiH3 (1), H3C-C6H4SiH3 (2), and H3CO-C6H4SiH3 (3) was performed to produce poly(MMA)s containing the respective silyl moiety as an end group. For all the hydrosilanes, the polymerization yields and the polymer molecular weights decreased, whereas the TGA residue yields and the relative intensities of Si-H IR stretching bands increased as the relative silane concentration over MMA increased. The polymerization yields and polymer molecular weights of MMA with 1-3 increased in the order of 3 < 1 < 2. These hydrosilanes influence significantly upon the photopolymerization of MMA as both chain-initiation and chain-transfer agents.

Nanopore Generation in Low Dielectric Organosilicate and SiCOH Thin Films

  • Heo, Kyu-Young;Yoon, Jin-Hwan;Jin, Kyeong-Sik;Jin, Sang-Woo;Oh, Kyoung-Suk;Choi, Chi-Kyu;Ree, Moon-Hor
    • Proceedings of the Polymer Society of Korea Conference
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    • 2006.10a
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    • pp.298-298
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    • 2006
  • There has been much interest in incorporating nanoscale voids into dielectric materials in order to reduce their k value, and thus in producing low-k porous interdielectric materials. One approach to the development of low-k dielectric materials is the templated polycondensation of organosilicate precursors in the presence of a thermally labile, organic polymeric porogen. The other is SiOCH films have low dielectric constant as well as good mechanical strength and high thermal stability through PECVD. In this article we explore the nanopore generation mechanism of organosilicate film using star-shape porogen and SiOCH film using bis-trimethylsilylmethane (BTMSM) precursor.

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Interaction of DEMS with H-terminated Si (001) Surface: A First Principles Study (DEMS와 H-terminated Si (001) 표면의 상호작용: 제일원리연구)

  • Kim, Dae-Hyun;Kim, Dae-Hee;Park, So-Yeon;Seo, Hwa-Il;Lee, Do-Hyoung;Kim, Yeong-Cheol
    • Journal of the Korean Ceramic Society
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    • v.46 no.4
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    • pp.425-428
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    • 2009
  • We performed a density functional theory study to investigate the interaction of DEMS (diethoxymethylsilane) with the H-terminated Si (001) surface. The optimum structure of DEMS was first calculated by a first principles study. The dissociation probability of the O-C bond of DEMS was higher than the other seven bonds based on the bond energy calculation. When the fragmented DEMS groups reacted with the H-terminated Si (001) surface, it was the most favorable among the eight reactions to form a bond between the Si atom on the surface and the O atom of a fragmented DEMS group (($C_2H_5O$)Si($CH_3$)(H)-O-) by forming a $C_2H_6$ as by-product.