Pattern transfer into low dielectric constant materials by high-density plasma etching

Directional plasma etching of low dielectric constant materials presents a rich spectrum of challenges owing to the multitude of inorganic, organic, a nd mixed organic/inorganic low dielectric constant materials being consider ed for multilevel interconnection applications. For organic materials we di scuss generic patterning issues and describe process development for hydroc arbon and fluorocarbon-based dielectrics. Porous materials are candidates f or ultralow dielectric constant material applications, and plasma etching o f porous silica exhibits important differences in surface processes relativ e to conventional SiO2. Two important surface cleaning processes for plasma -exposed metal and/or barrier layers are also discussed, as are their exten dibility to high-aspect-ratio features and compatibility with the low-k mat erial.