A damascene platform for controlled ultra-thin nanowire fabrication

This paper presents a damascene process for the fabrication of titanium micro/nanostructures and nanowires with adjustable thickness down to 2 nm. Their depth is precisely controlled by chemical-mechanical planarization together with in-process electrical characterization. The latter, in combination with a model of the titanium resistivity versus thickness, allows control of the metal line depth in the nanometer range. In summary, we have developed a planarization end point detection method for metal nanostructures. In addition, the model adopted covers geometrical influences like oxidation and ageing. The fabricated titanium nanowire test structures have a thickness ranging from 2 to 25 nm and a width ranging between 15 and 230 nm.