Low dielectric constant materials and methods for interlayer dielectric films in ultralarge-scale integrated circuit multilevel interconnections

This paper reviews low dielectric constant materials for interlayer dielectric films in ultralarge-scale integrated circuit (ULSI) multilevel interconnections. The trends of ULSIs in the last decade were briefly described first. Then, the requirements for interlayer dielectric film properties and their formation techniques were explained. They are: (1) a low dielectric constant, (2) a surface planarity, (3) a gap-filling capability, and (4) a low residual stress. In contrast with the requirements, the interlayer dielectric films and related technologies developed in the last decade were reviewed. In the requirements, the low dielectric constant materials are strongly required because the device performance has been limited by signal propagation time and cross-talk in the multilevel interconnections. Furthermore, the low dielectric constant is also required for reduction of power consumption in ULSI operation. Finally, the low dielectric constant materials were summarized, and future trends of the low dielectric constant interlayer dielectric film technologies are discussed.