Characterization of Nano-crystalline Diamond Films Grown Under Continuous DC Bias During Plasma Enhanced Chemical Vapor

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1203-J05-03

Characterization of nano-crystalline diamond films grown by continuous DC bias during plasma enhanced chemical vapor deposition V. Mortet1,2, L. Zhang3, M. Eckert4, A. Soltani5, J. D’Haen1,2, O. Douhéret6, M. Moreau7, S. Osswald8, E. Neyts4, D. Troadec5, P. Wagner1,2, A. Bogaerts4, G. Van Tendeloo3, K. Haenen1,2. 1

Institute for Materials Research (IMO), Hasselt University, Diepenbeek, Belgium. Division IMOMEC, IMEC vzw, Diepenbeek, Belgium. 3 Electron Microscopy for Materials Science (EMAT), University of Antwerp, Antwerpen, Belgium. 4 Research group PLASMANT, Department of Chemistry, University of Antwerp, Antwerp, Belgium. 5 Institut d'Electronique de Microélectonique et de Nanotechnologie, Villeneuve d'Ascq, France. 6 Service de la Chimie des Materiaux Nouveaux, MateriaNova Research Center, Mons, Belgium. 7 Laboratoire de Spectrochimie Infrarouge et Raman, Villeneuve d'Ascq, France. 8 Department of Materials Science and Engineering and A. J. Drexel Nanotechnology Institute, Drexel University, Philadelphia, USA 2

ABSTRACT Nanocrystalline diamond films have generated much interested due to their diamond-like properties and low surface roughness. Several techniques have been used to obtain a high renucleation rate, such as hydrogen poor or high methane concentration plasmas. In this work, the properties of nano-diamond films grown on silicon substrates using a continuous DC bias voltage during the complete duration of growth are studied. Subsequently, the layers were characterised by several morphological, structural and optical techniques. Besides a thorough investigation of the surface structure, using SEM and AFM, special attention was paid to the bulk structure of the films. The application of FTIR, XRD, multi wavelength Raman spectroscopy, TEM and EELS yielded a detailed insight in important properties such as the amount of crystallinity, the hydrogen content and grain size. Although these films are smooth, they are under a considerable compressive stress. FTIR spectroscopy points to a high hydrogen content in the films, while Raman and EELS indicate a high concentration of sp2 carbon. TEM and EELS show that these films consist of diamond nano-grains mixed with an amorphous sp2 bonded carbon, these results are consistent with the XRD and UV Raman spectroscopy data. INTRODUCTION In all times, its excellent properties have always stirred up the interest for diamond. Due to the excellent mechanical properties of this material, smooth nano-diamond thin films could be applied in micro-electro-mechanical systems (MEMS) [1]. Moreover, nano-diamond particles have generated an intense interest in microbiology [2,3] as, for instance, active biocompatible bio-markers. While nano-diamond thin films, i.e. films made of diamond nano particles embedded in an amorphous and non diamond carbon phase, are produced by chemical vapor deposition (CVD) techniques, the most used technique to produce nano-diamond particles is based on a detonation process, which is a cumbersome and hard to control industrial process [2]