Effect of deposition temperature on properties of boron-doped diamond films on tungsten carbide substrate
(School of Mechanical Engineering, Shanghai Jiao Tong University, Shanghai 200240, China)
Abstract: Boron-doped diamond (BDD) films were deposited on the tungsten carbide substrates at different substrate temperatures ranging from 450 to 850 °C by hot filament chemical vapor deposition (HFCVD) method. The effect of deposition temperature on the properties of the boron-doped diamond films on tungsten carbide substrate was investigated. It is found that boron doping obviously enhances the growth rate of diamond films. A relatively high growth rate of 544 nm/h was obtained for the BDD film deposited on the tungsten carbide at 650 °C. The added boron-containing precursor gas apparently reduced activation energy of film growth to be 53.1 kJ/mol, thus accelerated the rate of deposition chemical reaction. Moreover, Raman and XRD analysis showed that heavy boron doping (750 and 850 °C) deteriorated the diamond crystallinity and produced a high defect density in the BDD films. Overall, 600-700 °C is found to be an optimum substrate temperature range for depositing BDD films on tungsten carbide substrate.
Key words: hot filament chemical vapor deposition; diamond film; boron doping; substrate temperature; tungsten carbide