Kelvin probe characterization of buried graphitic microchannels in single-crystal diamond

Abstract

In this work, we present an investigation by Kelvin Probe Microscopy (KPM) of buried graphitic microchannels fabricated in single-crystal diamond by direct MeV ion microbeam writing. Metal deposition of variable-thickness masks was adopted to implant channels with emerging endpoints and high temperature annealing was performed in order to induce the graphitization of the highly-damaged buried region. When an electrical current was flowing through the biased buried channel, the structure was clearly evidenced by KPM maps of the electrical potential of the surface region overlying the channel at increasing distances from the grounded electrode. The KPM profiling shows regions of opposite contrast located at different distances from the endpoints of the channel. This effect is attributed to the different electrical conduction properties of the surface and of the buried graphitic layer. The model adopted to interpret these KPM maps and profiles proved to be suitable for the electronic characterization of buried conductive channels, providing a non-invasive method to measure the local resistivity with a micrometer resolution. The results p. 2 demonstrate the potential of the technique as a powerful diagnostic tool to monitor the functionality of all-carbon graphite/diamond devices to be fabricated by MeV ion beam lithography.

Diamond-Based Multi Electrode Arrays for Monitoring Neurotransmitter Release

“…After implantation, high temperatures treatment is performed (> 950 • ) in high vacuum (∼ 10 −6 mbar) for 2 hours in order to induce the permanent conversion of the amorphized regions to a graphite-like phase. 16 graphitic micro-channels (width: ∼ 20µm, length: 1.4 − 1.9mm, thickness:∼ 250nm) were obtained at a depth of few µm [37]. The graphitic channels are soldered by flip-chip technique to a polymer-ceramic composite chip carrier (Roger 4003) to allow the connection with the custom front-end electronics.…”

Effect of Composition and Surface Microstructure in Self-Polarized Ferroelectric Polymer Films on the Magnitude of the Surface Potential

“…It is emphasized that the formed surface potential always consists of polarization and surface charge [14][15][16]. The development of this method has allowed its use in specific problems, such as the detection of graphite microchannels in diamonds [17], and, in general, it is considered promising in electrochemistry [2]. Considerably less attention is paid to the application of this method to the analysis of a relatively new class of organic polymeric ferroelectrics, which, due to the specific properties of the condensed state of chain molecules, have found application in a number of areas of engineering and biomedicine [18][19][20][21].…”