Microporous polyimide films for reduced dielectric applications [electronic resource].
- Published
- Washington, D.C. : United States. Dept. of Energy, 1996.
Oak Ridge, Tenn. : Distributed by the Office of Scientific and Technical Information, U.S. Dept. of Energy. - Physical Description
- 15 pages : digital, PDF file
- Additional Creators
- Sandia National Laboratories, United States. Department of Energy, and United States. Department of Energy. Office of Scientific and Technical Information
Access Online
- Restrictions on Access
- Free-to-read Unrestricted online access
- Summary
- Limiting factor to computer chip speed and size is the dielectric constant of the interlayer insulating materials, which has been reduced going from inorganic to organic type materials. A further reduction, together with better mechanical properties, is still needed. We have developed a spincoating method in conjunction with a thermodynamic process (Non-solvent Induced Phase Separation) to create microporous polyimide films with both lower dielectric constant and better stress reduction properties compared to solid films. In this method, we spincoat a soluble polyimide solution in 1, 3-dimethoxybenzene solvent onto a Si wafer, and then immediately submerse the wet polymer film into a non-solvent bath, typically toluene. Phase separation of the polymer occurs on a micron size scale and the resulting microporous structure becomes locked in by the high glass transition temperature of the polyimide. Factors affecting film morphology, thickness, pore size, and % porosity include polymer concentration, spin speed, and non-solvent type. Morphology is explained in terms of thermodynamics and kinetics of phase separation and diffusion, using an idealized ternary phase diagram. One particular film having 68% porosity, 22 microns thickness, and 1.4 micron pore size had a dielectric constant of 1.88 and loss of 0.002. Stress measurements indicated that the microporous film reduced surface stress on the wafer by more than a factor of 10 compared to analogous solid polyimide film.
- Report Numbers
- E 1.99:sand--94-2831
sand--94-2831 - Subject(s)
- Other Subject(s)
- Note
- Published through SciTech Connect.
08/01/1996.
"sand--94-2831"
"DE96014163"
Saunders, R.S.; Aubert, J.H.; McNamara, W.F. - Funding Information
- AC04-94AL85000
View MARC record | catkey: 14109335