Micro-structures of nanodiamonds grown on silicon by hot filament chemical vapor deposition

A method to grow homogeneous micro-sized diamond clusters on silicon by Hot-Filament Chemical Vapor Deposition in a homemade reactor is reported in this work. Thermal decomposition of a CH₄:H₂ mixture gases was carried out in a horizontal quartz-tube reactor at 2200 °C filament temperature and 1000 °C substrate temperature at relative low pressure around 150 Torr depositing diamonds on silicon wafers. The diamond micro-structures are formed by nano-crystalline diamonds, they have a rounded shape and a narrow particle size distribution around a micrometer. The diamond micro-structures synthesized in this work showed a strong Raman shift signal, a peak at 1330 cm^-1 typical of the diamond and a single optical trap was localized nearby 300 ^oC by Thermoluminescence analysis indicating that these diamond micro-structures could be a good thermoluminescent dosimeter material. Due to their excellent properties, diamonds obtained by this technique should find application in the biomedical and optoelectronic industry.