Chemically Amplified, Positive Tone, Polynorbornene Dielectric for Microelectronics Packaging
| Autor: | Jared M. Schwartz, Brennen K. Mueller, Edmund Elce, Alexandra Sutlief, Paul A. Kohl, C. Grant Willson, Colin O. Hayes, William K. Bell |
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| Rok vydání: | 2014 |
| Předmět: |
Permittivity
chemistry.chemical_classification Materials science business.industry Electrical engineering Dielectric Polymer Thermal expansion Electronic Optical and Magnetic Materials chemistry.chemical_compound chemistry Copolymer Composite material Solubility business Curing (chemistry) Norbornene |
| Zdroj: | ECS Journal of Solid State Science and Technology. 4:N3001-N3007 |
| ISSN: | 2162-8777 2162-8769 |
| DOI: | 10.1149/2.0011501jss |
| Popis: | A low permittivity, positive tone, polynorbornene dielectric has been developed that exhibits excellent lithographic and electrical properties. The polymer resin is a random copolymer of a norbornene hexafluoroalcohol (NBHFA) and a norbornene tert-butyl ester (NBTBE). High optical sensitivity and contrast were achieved using a chemically amplified solubility switching mechanism through the acid-catalyzed deprotection of the tert-butyl ester functionality. After developing in aqueous base, the film was thermally cured through a Fischer esterification reaction, resulting in a cross-linked permanent dielectric. The effect of the photoacid generator (PAG) concentration on the lithographic patterning and curing reactions was studied. Higher PAG loading was favorable for both sensitivity and dielectric constant. The sensitivity of a formulation was measured as low as 8.09 mJ/cm2. The molar ratio of the two monomers composing the polymer was varied. A higher NBHFA content was favorable because it resulted in a lower modulus, lower shrinkage, and lower dielectric constant and loss. A formulation with 70 mol% of the NBHFA had a modulus of 2.60 GPa, a 12.2% volume decrease during cure, and a dielectric constant of 2.23. The direction-dependent coefficient of thermal expansion was measured, and it was found that the anisotropy of the PNB films decreased with higher NBTBE content. © The Author(s) 2014. Published by ECS. This is an open access article distributed under the terms of the Creative Commons Attribution 4.0 License (CC BY, http://creativecommons.org/licenses/by/4.0/), which permits unrestricted reuse of the work in any medium, provided the original work is properly cited. [DOI: 10.1149/2.0011501jss] All rights reserved. |
| Databáze: | OpenAIRE |
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