High Quality P‐Type GaN Deposition on c‐Sapphire Substrates in a Multiwafer Rotating‐Disk Reactor

Very high quality p‐type thin films have been epitaxially grown on c‐sapphire substrates by the MOCVD technique in a multiwafer rotating‐disk reactor at 1040°C with a buffer layer of ∼200 Å grown at 530°C. The undoped films have a low n‐type background carrier concentration of with an x‐ray of 280 arc‐sec across the 1 in. substrate. Biscyclopentadienyl magnesium was used as the precursor , the p‐dopant. The Mg‐doped wafers retained an excellent surface morphology. In addition, after post annealing in ambient at ∼700°C for an hour, the Hall measurements show carrier concentration depending on flow rate, with a hole mobility of 10–20 cm 2 /V‐s which is the best mobility for those hole concentrations reported in the literature to date.