表面极性对ZnMgO/ZnO异质结中二维电子气形成的影响

In this work, ZnMgO/ZnO heterostructures were grown on c-plane (0001) sapphire single crystal substrates using radio frequency magnetron sputtering. Effects of sputtering power and oxygen partial pressure on the properties of ZnMgO/ZnO heterostructures were studied. It is shown hat oxygen partial pressure play an important role in the electrical conductivity of ZnMgO/ZnO heterostructures. Decreasing oxygen partial pressure results in an increase in the electrical conductivity from semi-insulating to semiconducting. On the other hand, sputtering power shows less effect on the electrical properties of ZnMgO/ZnO heterostructures. Surface polarity of ZnMgO/ZnO heterostructures is determined to be O-polar using etching process and surface morphology analysis, resulting in non-formation of two dimentional electron gas at the ZnMgO/ZnO heterostructures interface.