PURPOSE: To form a cBN film highly adhesive even to a substrate of intricate shape.
CONSTITUTION: The vapor 10 of boron 9 is deposited on a substrate 4A set in a vacuum chamber 1, and the deposit is simultaneously irradiated with the nitrogen ion or mixture of nitrogen and rare gas ions 7 from an ion source 5. In this case, an accelerating voltage of the ion 7 is firstly made higher than the case where a cubic carbon nitride film is formed, the substrate 4A is rotated, the substrate 4A is irradiated with the ion while gradually changing the irradiation direction from vertical to ±90° to form a compositionally gradient layer in which the surface consists of pure boron nitride, and then a boron nitride film consisting essentially of the cubic crystal is formed.
WADA TETSUYOSHI
YAMASHITA NOBUKI
WATANABE TOSHIYA
