PROTECTIVE COATINGS OF AMORPHIC DIAMOND ON FRAGILE AND SENSITIVE SUBSTRATES

Amorphic diamond films can be grown with a laser plasma discharge source in an ultrahigh vacuum environment without the use of any catalyst. This technique produces films that adhere more readily to substrates. Described here is a study of the bonding and properties realized in one such example, the deposition of amorphic diamond on germanium. Measurements with Rutherford-backscattering spectrometry and transmission electron microscopy showed that the diamond coatings deposited from laser plasmas were bonded to the germanium substrates through an interfacial layer 200-300 angstrom thick. Resistance to wear was estimated with a modified sandblaster and it was shown that a coating of only 1.4 mum of amorphic diamond can increase the lifetime of samples by a factor of better than 12. Results of other mechanical measurements such as hardness and friction tests are also described.