X-ray reflectivity study on nanoporous organosilicates

Silicon dioxide with a dielectric constant of 4.0 is commonly used as a dielectric insulator for IC applications, i.e., interlayer dielectrics to separate metal interconnects. With the need for a smaller feature size, silicon dioxide no longer meets the requirements of a lower dielectric constant material. As such, ultra low-k organic-inorganic nanoporous materials such as organosilicates are one of the leading candidates for replacing silicon dioxide as interlayer dielectrics. In order to develop and optimize future ultra low-k interlayer dielectrics, characterization of material properties is important.; X-ray reflectivity has been recognized as a popular technique to characterize nanoporous thin films in terms of density, thickness, and coefficient of thermal expansion. This technique also provides insights into internal microstructures such as dominant orientation of pores. In this thesis, characterization of ultra low-k nanoporous thin films generated with two types of porogens has been studied using X-ray reflectivity technique.