A plasma damage resistant ultra low-k hybrid dielectric structure for 45nm node copper dual-damascene interconnects

A plasma damage resistant hybrid (polyarylene ether (PAR)/SiOC) dielectric structure using the ultra low-k (ULK) films with k value of 2.2 was demonstrated for Cu dual-damascene (DD) interconnects. The reliability issues attributed to plasma process induced damage to ULK films were clarified and resolved. As well as ULK film selection with plasma damage resistance, insertion of a low-k buffer layer with k value of 3.0 between SiOC and PAE and damage restoration process using hydrophobic treatment were found to be most important factors for robust ULK process integration.