Epitaxial overgrowth of 13C diamond films on diamond substrates predamaged by ion implantation
Epitaktisches Überwachsen von 13C Diamentfilmen auf durch Ionenimplantation vorgeschädigten Diamantsubstraten
Homoepitaxial chemical vapor deposited (CVD) 13C diamond films were grown on (100) diamond substrates predamaged by implantation with 620 keV Xe ions. The structural quality of the overgrown films was analyzed by plain-view and cross-sectional micro-Raman spectroscopy. Implantation doses below 2 x 10(exp 14) cm(exp -2), for which no damage detectable by Raman spectroscopy was observed in the substrate, had no effect on the quality of the overgrown films. For doses around 4 x 10(exp 14) cm(exp -2) , a pronounced predamage of the diamond substrate was found which had a strong degrading effect on the quality of the overgrown layer resulting in a drastic increase of the width of the optic zone-center phonon and in the appearance of Raman scattering from sp2-bonded carbon. Higher implantation doses up to 1 x 10(exp 15) cm(exp -2) resulted in a complete etch removal of the predamaged graphitic surface layer during the initial phase of CVD growth, which thus had no effect on the quality of th e film produced by the subsequent overgrowth.