Various processes were investigated to etch the low kappa dielectric material SiLK(TM). Because SiLK is a polymeric material, the two main process options are either an oxidizing or a reducing etch gas mixture which uses either oxygen or hydrogen as the main etchant gas, respectively. Hydrogen-based etch processes were found to have a large process window but slow etch rates and minimal profile control. When oxygen was used as the primary etch gas, a hydrocarbon was added for sidewall passivation. These oxygen-based processes demonstrated higher etch rates, and the addition of ethylene provided more control of the etch profile. The oxygen to ethylene flow ratio was found to be the dominant factor controlling the etch profile. Reduced hardmask faceting was achieved for both the hydrogen-based and oxygen-based processes by running with low rf power. Significant changes in etch rate, profile angle, and hardmask faceting were observed as the photoresist was cleared from the hardmask during the etch. These changes are caused by the changing etch chemistry as a result of the dramatic reduction in the area of organic film exposed to the plasma. Finally, the transfer of the final process to another organic film, FLARE(TM) was demonstrated.