Acetylene-terminated low-stress polyimide oligomer for interlayerdielectric applications

摘要

The authors describe a novel low-stress, acetylene-terminatedpolyimide well suited as the interlayer dielectric for MCMs (multichipmodules). For successful application as an interlayer dielectric in ahigh-density microelectronic package, organic polymers must possess avariety of demanding properties, e.g. processibility, mechanicalstrength, adhesion, low dielectric constant, low water absorption,minimal outgassing, low thermal expansion, etc. The appropriate balanceof properties depend upon the specific application. The authors describea unique, oligomeric approach toward providing these balanced propertieswith the ability to customize the final product performance. It is shownhow the thermal expansion and resulting residual film stress can becontrolled by the proper choice of oligomeric structure. Acetyleneend-capped polyisoimide oligomers with low thermal expansion from whichlow-stress dielectric films can be prepared are demonstrated. Theproperties and processing of these films are discussed and compared toconventional acetylene end-capped polyimide films