Correlation of the electrical, thermal, and optical properties of CVD diamond films by scanning microscopy techniques

Abstract Scanning electron microscopy (SEM) and scanning probe techniques (SFM, STM, SThM) were used to analyse microwave plasma-deposited polycrystalline CVD diamond films grown from C/H and C/H/O gas mixtures. Wavelength- and time-resolved cathodoluminescence (CL) and electron beam-induced current (EBIC) investigations were done in modified scanning electron microscopes. High lateral resolution analysis was carried out by scanning force (SFM) and scanning tunnelling (STM) microscopy. STM-EBIC investigations using a modified SFM in contact current mode (CCM-SFM) and thermal profiling (SThM) resulted in high-resolution images of the electrical and thermal properties of the diamond films. The various methods used allowed us to measure morphological, electrical and thermal properties of polycrystalline diamond, to detect defects, special features and structures of the grains and the grain boundaries and to connect the results with the preparation conditions, e.g. the composition of the CVD gas phase.