Morphological, cathodoluminescence and thermoluminescence studies of defects in diamond films grown by HF CVD technique

Abstract

A set of diamond layers was synthesized by Hot Filament Chemical Vapor deposition (HF CVD) from methanol-hydrogen (CH3OH–H2) gas mixture. By changing feed gas composition the obtained diamond films show different morphologies and microcrystal sizes as indicate the Scanning Electron Microscopy (SEM) pictures.The obtained diamond films were analysed by Scanning Electron Microscopy (SEM), X-ray diffraction (XRD), cathodoluminescence (CL) and thermoluminescence (TL) spectroscopy.The diamond's microcrystallities preferred orientation in diamond layers was assessed from X-ray diffraction measurements and described by texture coefficient TC(hkl). The cathodoluminescence study clearly shows that relative intensities of the band at 430 nm and at 605 nm changes as the preferred orientation changes from <400> to <220>. It was also shown that the morphology and the microcrystallities preferred orientation has an essential influence on the thermoluminescence properties of polycrystalline diamond layers.