Large Molecular Weight Nitroxide Biradicals Providing Efficient Dynamic Nuclear Polarization at Temperatures up to 200 K
摘要:
A series of seven functionalized nitroxide biradicals (the bTbK biradical and six derivatives) are investigated as exogenous polarization sources for dynamic nuclear polarization (DNP) solid-state NMR at 9.4 T and with ca. 100 K sample temperatures. The impact of electron relaxation times on the DNP enhancement (epsilon) is examined, and we observe that longer inversion recovery and phase memory relaxation times provide larger E. All radicals are tested in both bulk 1,1,2,2-tetrachloroethane solutions and in mesoporous materials, and the difference in E between the two cases is discussed. The impact of the sample temperature and magic angle spinning frequency on epsilon is investigated for several radicals each characterized by a range of electron relaxation times. In particular, TEKPol, a bulky derivative of bTbK with a molecular weight of 905 g.mol(-1), is presented. Its high-saturation factor makes it a very efficient polarizing agent for DNP, yielding unprecedented proton enhancements of over 200 in both bulk and materials samples at 9.4 T and 100 K. TEKPol also yields encouraging enhancements of 33 at 180 K and 12 at 200 K, suggesting that with the continued improvement of radicals large e may be obtained at higher temperatures.
Large Molecular Weight Nitroxide Biradicals Providing Efficient Dynamic Nuclear Polarization at Temperatures up to 200 K
摘要:
A series of seven functionalized nitroxide biradicals (the bTbK biradical and six derivatives) are investigated as exogenous polarization sources for dynamic nuclear polarization (DNP) solid-state NMR at 9.4 T and with ca. 100 K sample temperatures. The impact of electron relaxation times on the DNP enhancement (epsilon) is examined, and we observe that longer inversion recovery and phase memory relaxation times provide larger E. All radicals are tested in both bulk 1,1,2,2-tetrachloroethane solutions and in mesoporous materials, and the difference in E between the two cases is discussed. The impact of the sample temperature and magic angle spinning frequency on epsilon is investigated for several radicals each characterized by a range of electron relaxation times. In particular, TEKPol, a bulky derivative of bTbK with a molecular weight of 905 g.mol(-1), is presented. Its high-saturation factor makes it a very efficient polarizing agent for DNP, yielding unprecedented proton enhancements of over 200 in both bulk and materials samples at 9.4 T and 100 K. TEKPol also yields encouraging enhancements of 33 at 180 K and 12 at 200 K, suggesting that with the continued improvement of radicals large e may be obtained at higher temperatures.
POLISHING COMPOSITE FOR USE IN LSI MANUFACTURE AND METHOD OF MANUFACTURING LSI
申请人:SHOWA DENKO K.K.
公开号:EP1193745A1
公开(公告)日:2002-04-03
A polishing composition for an LSI device, comprising water, abrasive particles, an organic acid and an oxidizing agent and having the pH adjusted to 5.5-9.0 with an alkali substance, for the purpose of increasing the polishing rate for Ta and TaN during polishing of a Ta or TaN barrier metal (4) and a copper wiring layer (6), to prevent dishing and erosion. A manufacturing process for an LSI device using the polishing composition for polishing of a copper-based metal wiring layer (6) having copper (5a, 5b, 6) deposited on an insulating film (2) by way of a barrier metal (4) composed of Ta or TaN.
一种用于 LSI 器件的抛光组合物,由水、研磨颗粒、有机酸和氧化剂组成,并用碱物质将 pH 值调节至 5.5-9.0,用于在 Ta 或 TaN 阻挡金属 (4) 和铜布线层 (6) 的抛光过程中提高 Ta 和 TaN 的抛光率,以防止剥离和侵蚀。一种 LSI 设备的制造工艺,使用该抛光组合物抛光铜基金属布线层 (6),该铜基金属布线层 (6) 通过由 Ta 或 TaN 组成的阻挡金属 (4) 沉积在绝缘膜 (2) 上。
LSI device polishing composition and method for reproducing LSI device
申请人:——
公开号:US20020017064A1
公开(公告)日:2002-02-14
The present invention provides an LSI device polishing composition containing water, abrasive grains, an organic acid, and an oxidizing agent, and having a pH of 5.5-10.0 adjusted by an alkaline substance, the LSI device polishing composition being used for polishing a copper-containing metal wiring layer in which copper is deposited on an insulating film via barrier metal formed of Ta or TaN; and a method for producing LSI devices by use of the polishing composition. During polishing of a barrier metal such as Ta or TaN and a copper wiring layer, the rate of polishing Ta or TaN can be enhanced, to thereby prevent dishing and erosion.
本发明提供了一种 LSI 器件抛光组合物,该组合物含有水、磨粒、有机酸和氧化剂,并通过碱性物质调节 pH 值为 5.5-10.0,该 LSI 器件抛光组合物用于抛光含铜金属布线层,其中铜通过由 Ta 或 TaN 形成的阻挡金属沉积在绝缘膜上;本发明还提供了一种通过使用该抛光组合物生产 LSI 器件的方法。在Ta或TaN等阻挡层金属和铜布线层的抛光过程中,可以提高Ta或TaN的抛光速度,从而防止剥离和侵蚀。
LSI device polishing composition and method for producing LSI device
申请人:SHOWA DENKO K.K.
公开号:US20030153188A1
公开(公告)日:2003-08-14
The present invention provides an LSI device polishing composition containing water, abrasive grains, an organic acid, and an oxidizing agent, and having a pH of 5.5-10.0 adjusted by an alkaline substance, the LSI device polishing composition being used for polishing a copper-containing metal wiring layer in which copper is deposited on an insulating film via barrier metal formed of Ta or TaN; and a method for producing LSI devices by use of the polishing composition. During polishing of a barrier metal such as Ta or TaN and a copper wiring layer, the rate of polishing Ta or TaN can be enhanced, to thereby prevent dishing and erosion.
本发明提供了一种 LSI 器件抛光组合物,该组合物含有水、磨粒、有机酸和氧化剂,并通过碱性物质调节 pH 值为 5.5-10.0,该 LSI 器件抛光组合物用于抛光含铜金属布线层,其中铜通过由 Ta 或 TaN 形成的阻挡金属沉积在绝缘膜上;本发明还提供了一种通过使用该抛光组合物生产 LSI 器件的方法。在Ta或TaN等阻挡层金属和铜布线层的抛光过程中,可以提高Ta或TaN的抛光速度,从而防止剥离和侵蚀。
Oxoammonium salts. 5. A new synthesis of hindered piperidines leading to unsymmetrical TEMPO-type nitroxides. Synthesis and enantioselective oxidations with chiral nitroxides and chiral oxoammonium salts
作者:Zhenkun Ma、Qingtao Huang、James M. Bobbitt
DOI:10.1021/jo00070a018
日期:1993.8
A new synthesis of unsymmetrical 2,2,6,6-tetraalkyl-4-piperidones from acetonin (2,2,4,4,6-penta-methyl-2,3,4,5-tetrahydropyrimidine) and several ketones is described. When the ketone was a naturally occurring optically active ketone, the piperidones were optically active. The piperidones were converted to unsymmetrical TEMPO-type nitroxides and chiral nitroxides. The optically active nitroxides were used as catalysts for oxidations or converted to chiral oxoammonium salts. The structures of the chiral compounds were determined by 2D H-1 and C-13 NMR, and the cyclic voltammetric properties of the various nitroxides were measured. Several other pyrrolidine oxoammonium salts were prepared, and both types were used as oxidizing agents. Preliminary results of chiral oxidations are presented.