| This work focuses on the reactive ion etching and patterning of the low dielectric constant polymers parylene-n (pa-n) and benzocyclobutene (BCB), both candidates for use as interlayer dielectrics in future gigascale integrated circuits. These polymers have much lower dielectric constants than SiO;High-aspect ratio, submicron, anisotropic profiles were obtained in both pa-n and BCB at low pressures in pure O;Sputtering of the oxide hardmask due to ion bombardment was also found to affect the pattern shape, since it resulted in redeposition of hardmask material onto the feature sidewalls and bottoms. A minimum of CF;Dual damascene structures were fabricated with both single and dual hardmasks. Using a single hardmask, vertical sidewalls for both the via and trench were obtained in pa-n whereas via tapering occurred in the case of BCB. Overetching produced a thin wall of material protruding up from either side of the via due to redeposition of hardmask material. In the case of BCB, oxidation of the feature sidewall may also contribute to this effect. Adding a larger amount of CF... |
