MOLECULAR MODELING OF CVD OF (111)-ORIENTED DIAMOND FILM USING A KINETIC MONTE CARLO METHOD

摘要

The CVD of diamond from a small amount methane in hydrogen at subambient pressures has become commercially viable during the last decade. The gas mixture is heated by hot filaments or plasmas to dissociate the hydrogen, and the H atoms bond to the surface carbon atoms to passivate it by forming sp~3 bonds. White it is well understood that deposition of diamond involves incorporation of chemisorbed hydrocarbon radicals, the details of the diamond growth mechanism are still not well understood. There are several different modeling approaches used to analyse the diamond growth process. Molecular dynamics simulations are used to model depositions, but only over milliseconds. Recently, Dawnkaski et al. and Battaile et al. performed 3D atomic scale simulations of the (100) and (111) diamond surface growth. The original model of Battaile has been developed in the present work to include the fact that the same chemical reaction will be different depending on whether the reaction occurs on step edges or surface terraces. The method allows the surface chemistry, local atomic coordination, and surface structure to be incorporated into the simulation, and is capable of simulating hours of deposition under commonly used deposition conditions.