Hole trap levels in Mg-doped GaN grown by metalorganic vapor phase epitaxy

Hole trap levels in a Mg-doped GaN grown by metalorganic vapor phase epitaxy (MOVPE) are studied with deep level transient spectroscopy (DLTS). The Mg concentration of the sample was 4.8×1019 cm−3, but the hole concentration was as low as 1.3×1017 cm−3 at room temperature. The DLTS spectrum has a dominant peak D1 with activation energy of 0.41±0.05 eV, accompanied by two additional peaks with activation energies of 0.49±0.09 eV(D2) and 0.59±0.05 eV(D3). It was found that the dominant peak D1 consists of five peaks, each of which has different activation energy and capture cross section. A relevant model for these levels is presented in relation to the Mg–N–H complexes.