Method of making fullerene-decorated nanoparticles and their use as a low dielectric constant material for semiconductor devices

DETAILED DESCRIPTION The limitations of the prior art discussed above have, as of yet, not allowed the use of porous materials in semiconductor devices.
Several of these limitations are overcome or alleviated by the present invention, which provides a route to the preparation of fullerene-decorated inorganic nanoparticles with improved electrical properties, and methods for their deposition onto semiconductor wafers.
In accordance with the present invention, a solution is prepared that contains small particles (preferably less than 30 nm in diameter, and more preferably 2-10 nm in diameter) of a ceramic material (preferably silicon dioxide) that are decorated with a specific number of fullerene molecules (preferably <50% monolayer coverage, and more preferably 5-20% monolayer coverage).
Additionally, said solution contains a soluble component that is stable under ordinary conditions, but can be activated by thermal or other physical processes.
This component serves to bind the nanoparticles together by reacting with the fullerenes, the inorganic particle, or, preferably, both once activated.
Various possible routes exist to produce high surface area inorganic solids coated with fullerenes.
Lamb and Huffman describe in U.
S.
Pat.
No.
5,698,140 issued Dec.
16, 1997, a process for filling a silica, or other inorganic aerogel with fullerenes by chemical vapor deposition.
However, in this approach, the fullerenes are not chemically bound to the inorganic phase, but rather, are physisorbed, a situation not favorable to the present invention.
Stalling, et al.
in U.
S.
Pat.
No.
5,308,481 teach the binding of fullerenes to insoluble bulk silica, for use as column chromatography packing, using various organic coupling agents.
Chen, et al.
describe a similar process to bind fullerenes to solid substrates using organic coupling agent, and show that the bound fullerenes are capable of undergoing further insertion reactions (J.
A.
C.
S.
, 115 (1993), 1193-1194.
) The present invention also makes use of coupling agents to decorate inorganic nanoparticles with fullerenes