Synthesis of Nano-Crystalline Diamond Film in Hot FilamentChemical Vapour Deposition by Adding Ar

Nano-crystalline diamond films are successfully deposited on silicon substrates via the hot filament chemical vapour deposition process using a CH₄/H₂/Ar gas mixture. The as-grown films are analysed by using field emission scanning electron microscopy, micro-Raman spectroscopy and x-ray diffraction. These results show that the films consist of nano-diamond grains with sizes ranging from 10 to 100 nm, and argon is an important element in the formation of nano-crystalline diamonds.