Deposition of thermally stable, low dielectric constant fluorocarbon/SiO2 composite thin film

Low dielectric fluorocarbon/SiO2 composite films are developed that exhibit good thermal stability and low dielectric constant by using hexamethyldisiloxane (HMDSO) and prefluorobenzene (C6F6) as the monomer source gase's, and argon and oxygen as the carrier gases in a dual frequency, inductively-coupled high-density plasma reactor. Fourier transform infrared measurements of the films show that they consisted of both SiO2 and amorphous perfluoro tetra fluoroethylene,and the amount of each can be controlled by changing the feed monomer gas ratio, The dielectric constant of the film ranges between 2 and 4 depending on the feed monomer gas ratio. For example, when the monomer gas ratio [HMDSO/(HMDSO+C6F6)] is 0.2, the dielectric constant of the film is similar to 2.5, Such a composite film shows good thermal stability and good adhesion on a silicon substrate. (C) 1996 American Institute of Physics.