POLY(CHLORO-P-XYLYLENE) SIO2 MULTILAYER THIN-FILMS DEPOSITED NEAR ROOM-TEMPERATURE BY THERMAL CVD/

Multilayer thin films consisting of alternating layers of poly(chloro- p-xylylene) (PPXC) and silicon dioxide (SiO2) were deposited at 80-85 degrees C, taking advantage of a recently developed process to deposit SiO2 at near-room temperature by thermal chemical vapor deposition (C VD). The method used to deposit SiO2 is general and can be applied to near-room temperature deposition of many oxide thin films such as Al2O 3, Y2O3, TiO2, ZrO2, Ta2O5, Nb2O5, and ZnO; but for the development of low dielectric constant materials to reduce RC-delay in ultra large s cale integration (ULSI) devices, the deposition of SiO2 with a polymer ic material is more applicable. Further, the ability to deposit SiO2 i n a multilayer structure with a polymer is also advantageous to studyi ng ultrathin polymeric films which finds applicability where polymeric materials experience confined geometry such as in composite materials , lubrication and biocompatible ultrathin films. X-ray diffraction (XR D) results showed the presence of new crystallites in the homopolymer film after post-deposition anneal at 150 degrees C due to a decrease i n the d-spacing but after a 200 degrees C post-deposition anneal, only an increase in crystallinity occurred due the nucleation and growth o f new crystallites and not the growth of existing crystallites. Howeve r, the multilayer films were more sluggish to crystallize and to form new crystallites after post-deposition anneals as compared to PPXC as a result of a thickness effect at similar to 35 nm. The introduction o f a polymer with SiO2 raised the index of refraction from 1.44 to 1.59 (@630 nm) and lowered the dielectric constant from 4.0 to 3.30 (@10 k Hz) with a PPXC thickness fraction of similar to 0.80. (C) 1998 Elsevi er Science S.A. All rights reserved.