Laser processing and electrical analysis of embedded graphitic wires in diamond

Abstract

Ultrafast laser writing enables fabrication of three-dimensional structures (sub-micron scale) inside the bulk of diamond. High intensities in the focal volume of the laser cause lattice breakdown; as a result, diamond is transformed into a graphitic phase. Laser written graphitic wires embedded in the single crystal diamond find an application for electrodes in diamond detectors. Laser processing of graphitic columns requires a combination of certain parameters, including power, repetition rate, translation speed. Here, we explore the effect of the laser pulse energy on the electrical resistance of laser written graphitic columns that pass through the thickness of a CVD single crystal slab. We introduce a scheme that allows straightforward electrical analysis of the columns in an all-carbon device, without additional processing of the diamond, that allows for rapid optimisation of the laser parameters.