GROWTH OF EPITAXIAL ALXGA1-XN FILMS BY PULSED-LASER DEPOSITION

Epitaxial AlxGa1-xN films have been grown on c-cut sapphire substrates at 800 degrees C and 10(-2) Torr N-2 by pulsed laser deposition (PLD) using a KrF laser. Throughout the composition range from x=0 to 0.6, the films show epitaxial patterns in reflection high-energy electron d iffraction, in agreement with the results from x-ray diffraction. The lattice constants of the films vary linearly with x. The composition d ependence of the band gaps of the films deviates from linearity and bo ws downward. This letter reports the application of PLD to controlling the lattice constant and band gap by varying the proportion of AlN an d GaN in the target mixture. (C) 1998 American Institute of Physics. [ S0003-6951(98)01110-3].