Embodiments herein provide for oxygen based treatment of low-k dielectric layers deposited using a flowable chemical vapor deposition (FCVD) process. Oxygen based treatment of the FCVD deposited low-k dielectric layers desirably increases the Ebd to capacitance and reliability of the devices while removing voids. Embodiments include methods and apparatus for making a semiconductor device including: etching a metal layer disposed atop a substrate to form one or more metal lines having a top surface, a first side, and a second side; depositing a passivation layer atop the top surface, the first side, and the second side under conditions sufficient to reduce or eliminate oxygen contact with the one or more metal lines; depositing a flowable layer of low-k dielectric material atop the passivation layer in a thickness sufficient to cover the one or more metal lines; and contacting the flowable layer of low-k dielectric material with oxygen under conditions sufficient to anneal and increase a density of the low-k dielectric material