Efficient n-type doping of diamond using surfactant-mediated epitaxial growth

Fabrication of n-type diamond was studied by performing extensive first-principles total-energy calculations for a number of possible configurations during the epitaxial growth process. We find that spatially correlated codopant N-Al-N, which acts as a shallow donor in diamond, can be effectively formed by using a surfactant-based growth technique. This technique takes advantage of the difference in the growth modes of diamond which depend on surface species: incorporation of carbon into diamond crystal is promoted by surfactants (Al) but is locally prohibited by surface co-dopants (N-Al-N). Thus, the co-dopants are selectively buried in diamond. This approach provides a possible and very effective way to realize dense n-type doping of diamond which has not been possible using conventional techniques.