Present status and future trend of low-k dielectrics/interconnect technology for ULSI

This paper describes current development and future direction of low-k/interconnects. New materials such as Cu and low-k have been introduced to interconnect technology to meet the high-frequency operation of ULSIs. Porous low-k materials have been investigated to reduce the density of the films so as to reduce the dielectric constants. However, the introduction of new materials have caused considerable risks in integration. Reduction of the film density resulted in the reduction of mechanical strength, causing CMP adhesion failure. Further study is necessary to meet the requirements for both mechanical strength and lower k value.