Preparation and characterization of diamond film on Cu substrate using Cu-diamond composite interlayer
(1. School of Materials Science and Engineering, South China University of Technology, Guangzhou 510640, China;
2. New Materials Research Department, Guangzhou Research Institute of Nonferrous Metals,
Guangzhou 510651, China)
2. New Materials Research Department, Guangzhou Research Institute of Nonferrous Metals,
Guangzhou 510651, China)
Abstract: Large area diamond films were fabricated on copper substrates by a multi-step process comprised of electroplating Cu-diamond composite layer on Cu substrate, plating a Cu layer to fix the protruding diamond particles, and depositing continuous diamond film on composite interlayer by hot-filament chemical vapor deposition (HFCVD). The interface characteristics, internal stress and adhesion strength were investigated by scanning electron microscopy, Raman analysis and indentation test. The results show that the continuous film without cracks is successfully obtained. The microstructure of the film is a mixture of large cubo-octahedron grains grown from homo-epitaxial growth and small grains with (111) apparent facets grown from lateral second nuclei. The improved adhesion between diamond film and substrate results from the deep anchoring of the diamond particles in the Cu matrix and the low residual stress in the film.
Key words: diamond film; composites layer; electroplating; adhesion; chemical vapor deposition