Activation energy for diamond growth from the carbon-hydrogen gas system at low substrate temperatures

The growth kinetics of diamond films deposited at low substrate temperatures (600-400 degrees C) from the carbon-hydrogen gas system have been studied. When the substrate temperature alone was varied, independently of all other process parameters in the microwave plasma reactor, an activation energy:in the order of 7 kcal/mol was observed. This value did not change with different carbon concentrations in hydrogen. It is supposed that growth kinetics in this temperature range are controlled by a single chemical reaction, probably the abstraction of surface bonded hydrogen by gas phase atomic hydrogen. (C) 1997 American Institute of Physics.