Direct measurement of the adhesive fracture resistance of CVD diamond particles

Diamond film produced by chemical vapor deposition (CVD) is being used in t he electronic industry because of their excellent properties. In order to m easure the adhesive strength of CVD diamond, external load is directly appl ied in a scanning electron microscope to the CVD diamond particles that spa rsely appear on silicon substrate in the early stage of deposition. These p articles are called nuclei when they are small and grow into contact with e ach other to form polycrystalline CVD diamond film. Diamond film was suppos ed to adhere to the substrate fracture resistance, required to scratch off the particles with 2-13 mu-m diameter. Adhesive fracture resistance is foun d to increase with the diameter of the particle. Hence we conclude that CVD diamond does not adhere only at the nucleation points but that the whole c ontact area to the substrate is responsible for its adhesive strength.