Improvements of Stress Controllability and Radiation Resistance by Adding Carbon to Boron‐Nitride

The addition of an atom having different bonding radii to a matrix film is an effective method for changing the stress of the film. In a plasma‐enhanced CVD of BN, it is difficult to obtain tensile stress except for extremely boron‐rich films. The controllability of tensile stress in BN film was improved by introducing a small amount of carbon into the BN matrix, using plasma‐enhanced CVD between 400° and 500°C. We obtained transparent films with high Young's modulus and tensile stress. The radiation resistance of BNC deposited at 400°C was improved five times better than that of BN deposited by low‐pressure CVD at similar temperatures.