Controllable N-type Doping In Ultra-Wide Bandgap AlN By Chemical Potential Control

High mobility of 270 cm2/Vs and free electron concentration as high as 1015 cm-3 were achieved in Si doped AlN grown on AlN single crystal via point defect management. CN incorporation in homoepitaxial film was successfully reduced by increasing the V/III and growth temperature as two growth knobs during the MOCVD growth. This work demonstrates the Si doping limit in AlN as low as mid-1017 cm-3 via Chemical Potential Control during the deposition process. CN and threading dislocations are two acceptor-type compensators determining the low doping limit in n-type AlN. Suppression of these defects to further improve the low doping limit (minimum achievable carrier concentration along with the maximum mobility) opens up pathways for realization of AlN-based power electronic devices.