Study on the stability of HDP-SiOF film and IMD application for 0.25 /spl mu/m LSI device

A multilevel interconnection technology using an HDP-CVD SiOF film is demonstrated for 0.25 /spl mu/m LSI devices. A stable HDP-SiOF film is realized as the intermetal dielectric (IMD). When HDP-SiOF has Si-F/sub 2/ bonds and silicon dangling bonds, the film stress changes during thermal stressing. This unstable HDP-SiOF causes deformation of the metal underlayer due to the film stress change. The device performance with a stable HDP-SiOF film is improved, showing a 12% reduction in wiring capacitance. In addition, gate oxide leakage characteristics are also superior to those of conventional undoped silicate glass (USG). The stable HDP-SiOF film has been successfully applied as an IMD layer for 0.25 /spl mu/m LSI devices.