Acceptor activation of Mg-doped GaN—Effects of N2/O2 vs N2 as ambient gas during annealing

Here, we investigate the effects of O2:N2 (1:1) as ambient gas compared with pure N2 during activation annealing Mg p-type doping in GaN layers grown by MOCVD. The purpose is to understand impact O2 on resulting free hole concentration and mobility using SIMS, XRD, STEM, AFM, Hall effect measurements. Even though presence very effective reducing H level Mg-doped layers, maximum achievable still higher N2. differences are explained an in-diffusion O layer acting n-dopant and, thus, giving rise a compensation effect. Mg–H complexes at substitutional (MgGa), i.e., electrically active acceptor sites that provide holes, preferentially activated only gas, while also dissociates inactive much less residual H. At lower growth pressure 150 mbar 300 mbar, increasing carbon incorporation leads drastically unaffected.