Novel molecular-structure design for PECVD porous SiOCH films toward 45nm node, ASICs with k=2.3

A porous SiOCH film with k=2.3 is developed by a new concept PECVD, in which pore-involved molecules are piled up together to deposit a "molecular-pore stacked, SiOCH (MPS)" film. The pore size and the density of the film are controlled by designing the pore size and the steric-hindrance side-chains of the source molecules. A newly synthesized, 6-member ring-type, organo-siloxane with the side-chains of large steric-hindrance hydrocarbons realizes the MPS film with k=2.3. the basic feasibility of the MPS film is confirmed through the integration into Cu damascene interconnects. The MPS film is a strong candidate for the low-k, inter-metal-dielectrics in 45nm node, ASICs.