Growth of cubic boron nitride films on tungsten carbide substrates by direct current jet plasma chemical vapor deposition

Cubic boron nitride (cBN) film was deposited on Co-containing WC substrates by dc jet plasma chemical vapor deposition from an Ar-N₂-BF₃-H₂ gas system. The formation of cobalt nitrides was observed at interface, and the hindrance of Co on cBN growth was demonstrated. Growth temperature and etching treatment of the substrate before deposition infiuenced the cBN growth greatly. At 1050 °C, cBN films were obtained on etched substrates but not on unetched substrates. At 1090 °C, cBN films were not obtained even on etched substrates. At 960 °C, cBN films deposited even on unetched substrate but the films always peeled off after exposing to air. The film quality of cBN deposited at 960 °C is better than that deposited at 1050 °C.