The Effect Of Delta-Doping And Modulation-Doping On Si-Doped High Al Content N-Al-X Ga1-X N Grown By Mocvd

The effect of periodic delta-doping and modulation-doping on high Al content n-AlxGa1-xN (x = 0.55) epilayers grown by MOCVD has been investigated. Measured by XRD, AFM, contactless sheet resistance, and Hall-effect tests, delta-doped and modulation-doped n-AlxGa1-xN have better crystal quality, surface morphology and electrical properties as compared with uniformly-doped n-AlxGa1-xN. These improvements are attributed to the SiNx growth mask induced by delta-doping layers and the dislocation-blocking effect induced by both growth techniques. In addition, due to the broadened doping profile ascribed to enhanced dopant diffusion at high growth temperatures (1150 degrees C) of n-Al0.55Ga0.45N, modulation-doped n-Al0.55Ga0.45N has similar properties as delta-doped n-Al0.55Ga0.45N.