Ultra Low-k Materials Based on Self-Assembled Organic Polymers

Abstract

ABSTRACTThe material properties of two ultra low-k organic polymers are characterized for copper interconnect integration. The k-values are 2.2-2.3 for both. Compared to OSG materials of similar k-values, these polymers have lower porosity and smaller pore size, achieved using selfassembled chemistry. Both materials demonstrate excellent resistance to plasma damage: no water uptake was detected after exposure to selected etching plasmas. This characteristic, combined with the small pore size and low porosity, results in the successful integration of the organic low-ks in 80 nm spacing with no significant increase in the integrated k-values.It is found that higher open porosity in polymer A is accompanied by higher leakage current, which is not however linked to lower dielectric breakdown lifetimes.