New dopant precursors for n-type and p-type GaN

Tetraethylsilane (TeESi) and bis(ethylcyclopentadienyl)Mg (ECp₂Mg) were employed as Si and Mg dopant precursors for MOVPE growth of n-type and p-type GaN films, respectively. In Si doping, the electron concentration was observed to increase with the increase of the TeESi flow rate. The temperature dependence of the Hall mobility showed good agreement with n-type GaN films grown using different dopant precursors (SiH₄, GeH₄, Si₂H₆). The donor activation energy was estimated to be 27 meV, which is almost the same as the literature values. In Mg doping, we also found that the Mg concentration increases as the ECp₂Mg flow rate increases. All of Mg-doped samples in this study showed p-type conduction after annealing. The acceptor activation energy was estimated to be 170 meV, which was close to the reported values.