Fracture strength of free‐standing chemically vapor‐deposited diamond films

The fracture strength of free‐standing chemically vapor‐deposited diamond films was assessed by four‐point bending. A two‐parameter Weibull analysis was performed on 130 μm thick films resulting in a Weibull modulus of 4.3 and a statistical scaling stress of 626 MPa. The residual stress in films was measured from the free‐standing film curvature to be 384±10 MPa. The fracture surface chemistry was examined using scanning Auger spectroscopy. The fracture did not occur preferentially along grain boundaries.