Control of plasma polymerization reaction for the 2nd generation molecular_pore_stack (MPS) SiOCH film with high deposition rate

To reducing BEOL fabrication cost for 28/20nm-nodes, high-speed process of the low-k deposition is needed under limited equipment investment. By using a standard plasma-CVD equipment with no post-cure process, we have developed high speed deposition technique for a molecular_pore_stack (MPS) SiOCH film from single precursor, which has a hexagonal-silica-ring with hydrocarbon side-chains. Here, the plasma polymerization reaction of the precursors was enhanced simply by controlling the RF power and the gas chemistry with additive gas, which was dissociated itself to increase active charge flux in the plasma. The deposition rate was doubled while keeping the film properties unchanged with the sub-nanometer-size porous structure. No change in the RC performance of the Cu interconnect was observed by using the new MPS film with the high deposition rate. The mechanical properties also were preserved to keep chip-packaging-interaction tolerance.