Growth of p-Type AlN Crystals by C and Si Codoping

Based on our earlier theoretical investigation, p-type C:Si codoped AlN crystals were grown on SiC substrates by a sublimation method in a improved growth reactor. Hall-effect measurement shows that the AlN crystals have a high hole density of 1.4×1014 cm-3 and mobility of 52 cm2V-1s-1 in spite of the high resistivity (896 Ω•cm). In the AlN samples, Si dopants act as donors due to substituting Al atoms, and most of C dopants act as acceptors for replacing N atoms. It is also observed that the activation energy of C acceptors in C:Si codoped AlN is reduced by codoping Si donors, which agrees with the computational results.