Properties of high-performance porous SiOC low-k film fabricated using electron-beam curing

In this paper, we describe the effect of electron-beam (EB) curing on ultra-low-k dielectric porous SiOC material (k = 2.2) and the application of this technology to the 90-nm-node Cu/low-k multilevel damascene process. A significant improvement of dielectric porous SiOC films with EB curing has been demonstrated. The mechanical and adhesion strength of these films were increased by a factor of 1.5-1.6 without degrading the film's k. This result can be explained by the reconstruction of a Si-O random network structure from cage Si-O bonds and Si-CH3 bonds through EB curing. Additionally, the EB curing of spin-on dielectric (SOD) porous low-k films contributes to a decrease in their curing temperature and a decrease in their curing time. Under optimum EB curing conditions, no degradation of transistor performance was revealed. The excellent adhesion strength obtained by EB curing, has contributed to the success of multilevel damascene integration. On the basis of our findings, this EB curing technology can be applied in devices of 65-nm-node and higher.