Influences of nitridation treatment on the properties of semi-polar (11 <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" altimg="si1.svg"><mml:mrow><mml:mover accent="true"><mml:mn>2</mml:mn><mml:mo>‾</mml:mo></mml:mover><mml:mn>2</mml:mn></mml:mrow></mml:math>) plane AlGaN films

The characteristics of the semi-polar (11 2 ‾ 2) plane Al 0.34 Ga 0.66 N films grown with various nitridation time for m -plane substrate were investigated. The characterization results demonstrated that the surface flatness, crystalline quality as well as the PL full width at half maximum values were sensitive to the nitridation time, indicating that nitridation time is a key factor to achieve (11 2 ‾ 2) plane AlGaN films with high quality. Meanwhile, the background electron concentration in the epi-layer reduced by nearly two orders of magnitude via optimizing the nitridation time. These results made remarkably positive contributions to obtaining (11 2 ‾ 2)-orientated p-AlGaN films with high concentration, which is of great importance in fabricating high efficiency (11 2 ‾ 2)-orientated AlGaN-based light emitting diodes.