Periodic supply of indium as surfactant for N-polar InN growth by plasma-assisted molecular-beam epitaxy

We have investigated the self-surfactant effect of In for N-polar InN growth by plasma-assisted molecular-beam epitaxy. We found that InN quality was significantly improved if a thin In coverage (about 1.8 ML) was introduced before InN growth. However, this In coverage was slowly consumed during subsequent InN growth under N-rich condition. Periodically restoring In coverage for thick InN growth was proposed to solve this consumption problem. We suggest that the effect of In surfactant is to terminate the surface N dangling bonds and form an In adlayer, under which an efficient diffusion channel for lateral N adatom transport is created.