Simple, reliable Cu/low-k interconnect integration using mechanically-strong low-k dielectric material: silicon-oxycarbide

摘要

A new low-k material (silicon-oxycarbide, k=3.3) is developed to improve the mechanical strength of Cu/low-k interconnects. The film is shown to be over three-times stronger than conventional ones. The film qualities are high enough: the heat resistance is good up to 650°C, and the breakdown voltage is 5.5 MV/cm. The film is applied to interconnection test devices without using an oxide-cap. The k remains as low as 3.3, showing that an equivalent capacitance reduction with conventional materials (k=2.5-2.9) can be achieved using a simpler and more reliable structure.