PLASMA-PROCESSED FLUROCARBON FILM DEVELOPMENT AND SURFACE ANALYSIS FOR ADVANCED COPPER INTERCONNECT APPLICATION

摘要

Modifications of the classical SiO_2 film has been performed extensively using a wide variety of anions in the recent years. One such type of modified film that has indicated a promising future, is the fluorinated silicon glass thin film in deep submicron interconnect landscape. Films from this family have been proven to provide dielectric constant values that keep up with the current trends in the microelectronic industry. Work in this direction showed that k values vary inversely with the fluorine content in the films. The scope of this investigation revolves around the methodology of preparation of oxy fluoride film with the aid of a suitable plasma-assisted recipe and characterization of the prepared film via extensive surface and sub surface analytical tools. Surface morphology was taken into account with the help of the scanning electron microscope and helped to isolate better formed films and the desired film was then further analyzed for chemical composition using Auger electron spectroscopy and X-ray photoelectron spectroscopy. FEAuger depth profile analysis of plasma-assisted film formation indicate the composition between deposition and etching plasma gas chemistry variation. XPS quantified the film as 60%C, 35%F and 5%O, indicating that the carbon has 4 environments although predominantly C-F. The impact of plasma on surface and interface compositional changes has been identified and used to discuss its influence on dielectric properties.