Abstract
The growth of β-C3N4 crystallites is studied at various substrate temperatures by an inductively-coupled plasma sputtering method using 500 W of radio frequency power to enhance the gas dissociation. The crystallites deposited are demonstrated to be β-C3N4 phase rather than other phases from the transmission electron diffraction and the X-ray photoelectron spectroscopy results. Upon increasing the substrate temperature from 400°C to 800°C, β-C3N4 crystallite size increases from 0.02 µm to 0.2 µm, but the [N]/[C] atomic ratio in the film decreases slightly from 1.0 to 0.85, suggesting that the film contains larger β-C3N4 crystallites in a less nitrogenated amorphous carbon matrix at a higher temperature. The film deposited at 800°C exhibits a highly spotty transmission electron diffraction pattern and contains a high percentage (90%) of sp3 C-N bonding as estimated from X-ray photoelectron spectroscopy. The results suggest that a high substrate temperature enhances the formation of β-C3N4 crystallites at a high degree of gas dissociation.