REAL-TIME SPECTROELLIPSOMETRY STUDY OF THE EVOLUTION OF BONDING IN DIAMOND THIN-FILMS DURING NUCLEATION AND GROWTH

Real time spectroellipsometry (RTSE) has been performed during the nuc leation and growth of nanocrystalline thins films prepared by plasma-e nhanced chemical vapor deposition onto Si substrates. RTSE shows that a significant volume fraction of nondiamond (or sp(2)-bonded) carbon f orms during thin film coalescence and is trapped near the substrate in terface between similar to 300 Angstrom diamond nuclei. Although this behavior is observed over a range of CH4/H-2/O-2 gas compositions, the interfacial sp(2)-bonded carbon volume can be minimized by operating just within the growth-etch boundary of the diamond growth phase diagr am.