Si-doped n-type AlxGa1-xN alloys were grown by metalorganic chemical vapor deposition on sapphire substrates. We have achieved highly conductive n-type AlxGa1-xN alloys for x up to 0.7. A conductivity (resistivity) value of 6.7 -1 cm-1 (0.15 cm) (with free electron concentration 2.1×1018cm-3 and mobility of 20 cm2/Vs at room temperature) has been achieved for Al0.65Ga0.35N, as confirmed by Hall-effect measurements. Our experimental results also revealed that (i) the conductivity of Al xGa1-xN alloys continuously increases with an increase of Si doping level for a fixed value of Al content and (ii) there exists a critical Si-dopant concentration of about 1×1018cm-3 that is needed to convert insulating AlxGa1-xN with high Al content (x≥0.4) to n-type.
|Number of pages||3|
|Journal||Applied Physics Letters|
|State||Published - Aug 5 2002|