Kinetics of the isomerization reaction of cholest-5-en-3-one catalyzed by trichloroacetic acid in aprotic solvents of low dielectric constant

1982 ◽  
Vol 14 (8) ◽  
pp. 875-891 ◽  
Author(s):  
Francisco Salvador ◽  
José Luis Gonzalez ◽  
Miguel A. Herraez
Keyword(s):  
Dielectric Constant ◽  
Trichloroacetic Acid ◽  
Isomerization Reaction ◽  
Low Dielectric Constant ◽  
Aprotic Solvents ◽  
Low Dielectric ◽  
Kinetics Of

Preparation and Properties of Polyisoimides as a Highly Dimensionally Stable Polyimide Precursor with Low Dielectric Constant

1997 ◽  
Vol 9 (3) ◽  
pp. 333-344 ◽  
Author(s):  
Hiroshi Seino ◽  
Osamu Haba ◽  
Amane Mochizuki ◽  
Masahiro Yoshioka ◽  
Mitsuru Ueda
Keyword(s):  
Dielectric Constant ◽  
Dielectric Constants ◽  
Isomerization Reaction ◽  
Low Dielectric Constant ◽  
Low Dielectric ◽  
Fluorinated Polyimides ◽  
Wide Range ◽  
Biphenyltetracarboxylic Dianhydride ◽  
Polyimide Precursor ◽  
Dipolar Aprotic Solvents

Fluorinated polyimides (PIs) with low dielectric constant and high dimensional stability have been developed using polyisoimides (PIIs) as a polyimide precursor. The PIIs were prepared by the ring-opening polyaddition of the dianhydrides pyromellitic dianhydride, biphenyltetracarboxylic dianhydride and 4, 4′-hexafluoropropylidenedi(phthalic anhydride) with the diamines 2, 2′-dimethylbenzidine and 2, 2′-bis(trifluoromethyl)benzidine, followed by treatment with trifluoroacetic anhydride/triethylamine or dicyclohexylcarbodiimide in N;N-dimethylacetamide. The PIIs were soluble in a wide range of solvents including dipolar aprotic solvents, cyclohexanone and tetrahydrofuran at room temperature, and easy to convert to corresponding PIs by high thermal treatment. The resulting PIs showed low dielectric constants of less than 3 at 1 MHz as well as low CTEs. Furthermore, during the isomerization reaction, migration of copper in the PI film was hardly observed.

Structire, Properties, and Process Characteristics of Low-K Materials Prepared by PECVD

1999 ◽  
Vol 565 ◽  
Author(s):  
Y. Shimogaki ◽  
S. W. Lim ◽  
E. G. Loh ◽  
Y. Nakano ◽  
K. Tada ◽  
...  
Keyword(s):  
Growth Rate ◽  
Dielectric Constant ◽  
Gas Flow ◽  
Structural Changes ◽  
Silicon Oxide ◽  
Reactive Species ◽  
Low Dielectric Constant ◽  
Low Dielectric ◽  
Step Coverage ◽  
Low K

AbstractLow dielectric constant F-doped silicon oxide films (SiO:F) can be prepared by adding fluorine source, like as CF4 to the conventional PECVD processes. We could obtain SiO:F films with dielectric constant as low as 2.6 from the reaction mixture of SiH4/N2 O/CF4. The structural changes of the oxides were sensitively detected by Raman spectroscopy. The three-fold ring and network structure of the silicon oxides were selectively decreased by adding fluorine into the film. These structural changes contribute to the decrease ionic polarization of the film, but it was not the major factor for the low dielectric constant. The addition of fluorine was very effective to eliminate the Si-OH in the film and the disappearance of the Si-OH was the key factor to obtain low dielectric constant. A kinetic analysis of the process was also performed to investigate the reaction mechanism. We focused on the effect of gas flow rate, i.e. the residence time of the precursors in the reactor, on growth rate and step coverage of SiO:F films. It revealed that there exists two species to form SiO:F films. One is the reactive species which contributes to increase the growth rate and the other one is the less reactive species which contributes to have uniform step coverage. The same approach was made on the PECVD process to produce low-k C:F films from C2F4, and we found ionic species is the main precursor to form C:F films.

Defect free monolayer and bilayer graphene exfoliated by solvent with low dielectric constant

2020 ◽  
Author(s):  
Vedanki ◽  
Chandrabhan Dohare ◽  
Pawan KumarSrivastava ◽  
Premlata Yadav ◽  
Subhasis Ghosh
Keyword(s):  
Dielectric Constant ◽  
Bilayer Graphene ◽  
Low Dielectric Constant ◽  
Low Dielectric
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