Chemical Vapor Deposition of Diamond: Scientific Basis and Technological Opportunities

摘要

The chemical vapor deposition of diamond at low pressures where diamond is metastable with respect to graphite is now a relatively well established technology [1]. However, applications have lagged because of low diamond quality at high growth rates and because of high costs. In this paper the basic factors determining growth rates, energy consumption, and product quality are examined. The chemical vapor deposition of diamond is a highly irreversible process and is driven by "super-equilibrium" concentrations of atomic hydrogen. Energy is supplied to the system by the highly endothermic dissociation of H_2 to 2H by a plasma, hot filament or by combustion. The atomic hydrogen participates in a large number of chemical reactions, the net result of which is to provide a local environment in which graphitic, non-diamond material is gasified while diamond is simultaneously deposited. The overall thermodynamic process has been aptly called a "chemical pump" [2].