In this article, a methyl-doped silicon oxide low k film for use in inter-level dielectric application has been characterized. The structural and electrical properties of films prepared by chemical vapor deposition before and after different etching and photo-resist stripping (PRS) plasma treatments were studied. Structural properties of the low k film with various extents of forming gas and 0, plastria treatments were reflected by the contents of Si-CH3 and Si-H bonds. Surface roughness of films with plasma treatments was closely linked to the ratios of the cage- and network-structures of Si-O. Electrical properties of plasma-treated films were dependent on the applications of both etching and PRS plasma chemistries. Forming gas PRS caused the least low k film structural change and electrical deterioration compared with 0, treatment. Moreover, E-bd of films decreased significantly by CH2F2 versus C4F8 etch. The best electrical properties of the film was obtained with a leakage Current density of < 1 x 10(-8) A/cm(2) and a dielectric breakdown strength of similar to 3.2 MV/crn after being subjected with C4F8/N-2/Ar trench etch and forming gas PRS treatment. (c) 2005 Elsevier B.V. All rights reserved.