The organic low-k hybrid-organic-siloxane-polymer (HOSP(R)) has been investigated as an intermetal dielectric. The presence of Si-H and Si-CH3 bonds instead of partial Si-O bonds lowers the dielectric constant compared to conventional siloxane-based spin-on glass. However, dielectric degradation occurs due to the destruction of functional groups in HOSP during the photoresist ashing process. In this work, we have applied NH3 plasma nitridation to improve the quality of HOSP films. The NH3 plasma process converts the organic HOSP surface into an inorganic surface by formation of a thin inert SiNx passivation layer. The inert layer can enhance the resistance of the HOSP film to moisture uptake and O-2 plasma attack during photoresist stripping. In addition, it effectively prevents copper from penetrating the HOSP film. (C) 2001 The Electrochemical Society. All rights reserved.