Secondary-ion mass spectroscopy (SIMS) investigations of Be and Si incorporation in GaN grown by molecular beam epitaxy (MBE)

We have studied the incorporation of Be and Si in GaN grown using molecular beam epitaxy (MBE). From secondary-ion mass spectroscopy (SIMS) measurements, Be was found to have an enhanced diffusion rate at high concentration similar to the behaviour observed previously in GaAs. On the other hand, Si behaves as a conventional n-type dopant with no evidence from SIMS for either segregation or diffusion out of the layer. For Be-incorporated material we report new lines in the PL spectrum for both wurtzite and zinc blende polytypes, and we suggest that Be may be a suitable dopant for the zinc blende material.