Growth mechanism of vapor-deposited diamond

An elementary-reaction mechanism of diamond growth by a vapor deposition process is proposed. The central postulate is that the main monomer growth species is acetylene. The mechanism basically consists of two alternating steps: surface activation by H abstraction of a hydrogen atom from a surface carbon and the addition of one or two acetylene molecules. During the addition reaction cycle a number of solid C–C bonds is formed and hydrogen atoms migrate from a lower to an upper surface layer. The mechanism is in general agreement with the macroscopic views of the Russian researchers and is consistent with the numerous experimental observations reported in the literature.