Integration of SiOC air gaps in copper interconnects

Abstract

The formation of air gaps by means of a non-conformal chemical vapor deposition (CVD) on patterned wafers was successfully demonstrated using SiOC ( K=2.9) as inter-level metal dielectric. This paper presents the results on physical characterization and electrical performance evaluation of integrated SiOC air gaps in a three-metal level Cu/SiOC interconnect module. The influence of the air gaps shape on parasitic coupling capacitance between copper lines was also discussed in accordance with mask design rules and processing steps.