Plasma enhanced chemical vapor deposition of thermally stable and low-dielectric-constant fluorinated amorphous carbon films using low-global-warming-potential gas C5F8

Low-dielectric-constant fluorinated amorphous carbon films have been prepar ed from the low global-warming-potential gas of C5F8 by a capacitively coup led plasma enhanced chemical vapor deposition method. Films were prepared a t substrate temperatures as high as 400 degreesC. The obtained deposition r ate of 15-65 nm/min was higher than that of conventional C4F8 plasma at the same substrate temperature. The dielectric constant of the films varied fr om 2.1 to 2.5 with increasing RF power from 10 to 100 W. The residual thick ness of the films after 400 degreesC-thermal treatment was higher than 98%. At an RF power higher than 50 W, cracks appeared in the films that were ra pidly cooled from 400 degreesC to room temperature, and poor adhesion chara cteristics were obtained even for the samples without cracks after gradual cooling. On the other hand, the samples prepared at 10 W showed no cracks a nd good adhesion on a crystalline silicon substrate regardless of the cooli ng rate. (C) 2000 Elsevier Science S.A. All rights reserved.