A review of diamond CVD utilizing halogenated precursors

Halogenated carbon-hydrogen diamond chemical vapor deposition (CVD) systems have been observed to enhance low temperature growth, nucleation density a nd quality when compared to the more common carbon-hydrogen system. The mos t likely explanation for the enhanced low temperature growth and nucleation densities observed in the halogenated system are a product of high surface hydrogen abstraction rates, enabled by the addition of halogenated species . The increase in diamond quality in the halogenated systems can be account ed for by the preferential etching of graphite by Cl, F and HF. The possibl e participation of halogen containing radical species in the growth process has also been used to explain the observed results in halogenated diamond CVD systems. However, the short lifespan of these species makes their direc t participation in the growth process unlikely in most systems. Insufficien t data is available at this time to draw conclusions about halogenated diam ond CVD systems not involving F or Cl. (C) 1999 Elsevier Science S.A. All r ights reserved.