Interlayer dielectrics are key materials for size reduction and speed enhancement of ultra large scale integrated devices. As intralevel metal spacing is reduced and lower capacitance is required, the choices for inorganic dielectrics are limited. Fluorosilicate glass is a material that is being considered to meet these requirements because it has shown the ability to extend SiO2 chemical vapor deposition processing. Fluorine addition in a conventional glass improves gap fill while simultaneously lowering the dielectric constant. This paper will review the progress of fluorosilicate glass processing, examine the reliability of these materials, and discuss the role of fluorine in increasing gap fill and lowering the dielectric constant of standard SiO2 films.