Diamondlike carbon materials as low-k dielectrics for multilevel interconnects in ULSI

Abstract

Hydrogenated diamondlike carbon (DLC) and fluorine containing DLC (FDLC) were studied as low-k interlevel and intralevel dielectrics (ILD) for multilevel interconnects in ULSI, while silicon containing DLC (SiDLC) was studied as a potential low-k etch stop material. The dielectric constant (k) of the DLC films can be varied between >3.3 and 2.7 by changing the deposition conditions. FDLC films characterized by a dielectric constant of about 2.8 were found to have similar thermal stability as DLC films with >3.3. Thermally stable FDLC films have internal stresses of <300 MPa and are promising candidates as a low-k ILD. SiDLC films provide an effective etch-stop for oxygen reactive ion etching of DLC or FDLC films.