Impact of deposition technique on the chemical bonding in low-κ organosilicate glass (OSG) films and on porogen residues was studied using near edge X-ray absorption fine structure (NEXAFS) and internal photoemission (IPE) spectroscopy. The carried analysis reveals that self-assembly technology (SAT) allows one to obtain OSG-films without carbon residues, i.e. with “a clean bandgap”. Conventional PECVD film contains appreciable amount of carbon clusters, which account for gap states responsible for charge trapping and leakage current.