Abstract: A low dielectric constant nanotube, which can be used in the damascene process, and the fabrication method for a non-selective and a selective nanotube thin film layer are described. The non-selective deposition of the nanotube thin film layer includes forming a catalytic layer on the substrate followed by chemical vapor depositing a nanotube thin film layer on the catalytic layer. The selective deposition of the nanotube thin film layer includes forming a catalytic layer on the substrate followed by patterning the catalytic layer. A patterned photoresist layer can also form on the substrate, followed by forming multiple of catalytic layers on the photoresist layer and on the exposed substrate respectively. The photoresist layer and the overlying catalytic layer are removed. Thereafter, a nanotube layer is formed on the patterned catalytic layer by chemical vapor deposition.