Electrical and optical activation studies of Si-implanted AlxGa1-xN

Comprehensive and systematic electrical and optical activation studies of Si implanted Al$_{x}$Ga$_{1-x}$N grown on sapphire substrates by molecular beam epitaxial method have been made as a function of ion dose, anneal temperature, and anneal time. Si ions were implanted at 200 keV with doses ranging from 1x10$^{13}$ to 5x10$^{15}$ cm$^{-2}$. The samples were proximity cap annealed from 1100 to 1250$^{\circ}$C for 5 to 25 min with a 500 {\AA} thick AlN cap in a nitrogen environment. Both the sheet carrier concentration and electrical activation efficiency of Si-implanted Al$_{x}$Ga$_{1-x}$N increase continuously with anneal temperature and/or anneal time. The mobility also increase along with the increase in sheet carrier concentrations as the anneal temperature and/or anneal time increases, indicating successive damage recovery with increased anneal temperature and/or anneal time. The luminescence observations are consistent with the results of electrical activation studies.