Effect of N and B doping on the growth of CVD diamond (100):H(2×1) surfaces

The doping of the chemical vapor deposition (CVD)-diamond (100):H(2×1) surface with B and N has been studied using the density-functional tight-binding method. In agreement with recent experimental results, B doping is found to lower the abstraction energies and remove diffusion barriers along the diamond growth pathway proposed by Harris and Goodwin [J. Phys. Chem. 97, 23 (1993)]. In contrast, the Harris-Goodwin mechanism is less favorable with N doping, casting doubt on its validity in this case. We therefore propose a growth pathway on N-doped CVD diamond (100):H(2×1) surfaces. This involves a dimer opening reaction and requires less H abstraction reactions compared to the Harris-Goodwin mechanism.