Etching effects during the chemical vapor deposition of (100) diamond

Current theories of CVD growth on (100) diamond are unable to account for t he numerous experimental observations of slow-growing, locally smooth (100) (2x1) films. In this paper we use quantum mechanical calculations of diamon d surface thermochemistry and atomic-scale kinetic Monte Carlo simulations of deposition to investigate the efficacy of preferential etching as a mech anism that can help to reconcile this discrepancy. This etching mechanism a llows for the removal of undercoordinated carbon atoms from the diamond sur face. In the absence of etching, simulated growth on the (100)(2x1) surface is faster than growth on the (110) and (111) surfaces, and the (100) surfa ce is atomically rough. When etching is included in the simulations, the (1 00) growth rates decrease to values near those observed experimentally, whi le the rates of growth on the other surfaces remain largely unaffected and similar to those observed experimentally. In addition, the etching mechanis m promotes the growth of smooth (100) surface regions in agreement with num erous scanning probe studies. (C) 1999 American Institute of Physics. [S002 1-9606(99)70531-3].