Interconnects - A Porous Future

摘要

Interconnection technology is entering the era of the void. The requirement for low permittivity dielectrics has led the electronics community to reduce the material density of the dielectrics, whether that be a uniform density material or, as in the case of air gaps, the averaged density of the material between the lines. This trend results in a great many difficulties to ponder, and a considerable slip in the schedule for introducing these materials. The method of decreasing the k value in order to stay close to the International Technology Roadmap for Semiconductors (ITRS) is to increase porosity. However, this makes the dielectrics weaker and more susceptible to damage from etching, ashing, and polishing. Methods have emerged for handling these things, and the predicted scaling itself, in which aspect ratio is relatively constant makes possible shortened exposure to the processes that create damage layers.