Boron doped diamond films were deposited on the silicon substrate by hot-filament chemical vapour deposition(HFCVD).The effects of boron source flow on the conductivity,grain size,crystal direction and residual stress of boron doped diamond films were investigated.The results show that the resistance of diamond films decreases rapidly with increasing boron flux.After a certain flow rate,the defects and impurities increase and hinder the further decline of resistance.The boron flow increases gradually in 0-2...