Process of insulating a semiconductor device using a polymeric material
View Patent ↗A dielectric material formed by contacting a low dielectric constant polymer with liquid or supercritical carbon dioxide, under thermodynamic conditions which maintain the carbon dioxide in the liquid or supercritical state, wherein a porous product is formed. Thereupon, thermodynamic conditions are changed to ambient wherein carbon dioxide escapes from the pores and is replaced with air.
1. A process of insulating an electric assembly which includes semiconductor devices comprising the steps of:
(a) disposing a film of a polymeric material upon a surface of a semiconductor device;
(b) contacting said polymeric material with a porogen;
(c) contacting said porogen-included polymeric material with liquid or supercritical carbon dioxide under thermodynamic conditions consistent with the maintenance of carbon dioxide in said liquid or supercritical state; and
(d) adjusting said thermodynamic conditions under which said semiconductor device is maintained to those of ambient temperature and pressure.
2. A process in accordance with claim 1 wherein said polymeric material is selected from the group consisting of polyimides, fluorinated polymides, polyorganohydrosilanes, polysiloxanes, polyphenylenes, copolymers of divinylsiloxane and bisbenzocyclobutene, polybenzyl, polyarylethers and polyetrafluoroethylene.
3. A process in accordance with claim 2 wherein said polymeric material is polyphenlene.
4. A process in accordance with claim 1 wherein said porogen contacting step comprises disposing said porogen in a concentration of between about 0.1% end about 1% on a polyphenylene film, said percentages being by weight, based on the weight of said polyphenylene.
5. A process in accordance with claim 1 wherein said step (c) occurs at a temperature, in the range of between about 32° C. and about 100° C. and at a pressure in the range of between about 1,000 psi and about 8,000 psi.
6. A process in accordance with claim 1 wherein said porogen is selected from the group consisting of water, acetone, toluene, methanol, ethanol, propanol and mixtures thereof.
7. A process in accordance with claim 1 wherein said porogen is disposed on the surface of said polymeric material.
8. A process in accordance with claim 7 wherein said porogen is water.