Local electrostatic charging differences of sub‐100 nm nanocrystalline diamond films

Abstract

AbstractNanocrystalline diamond (NCD) thin films are deposited on p‐type Si substrates at different deposition temperatures (600–820 °C) in thicknesses below 100 nm. The films are then terminated by oxygen using r.f. oxygen plasma. Atomic force microscopy (AFM) is used to induce electrostatically charged micrometer‐sized patterns on the diamond films by applying a bias voltage on the AFM tip during a contact mode scan. Trapped charge is detected by Kelvin force microscopy, showing potential shifts different in geometry and amplitude on each film for the same absolute bias voltages. The films have similar structure and grain size, measured by AFM and scanning electron microscope (SEM). Fourier transform infrared spectroscopy (FTIR) in reflection regime shows the solidity of the films. Material differences are resolved via micro‐Raman spectroscopy. Different charging properties are thus attributed to the differences in relative amount of diamond and sp2 phase.