STRUCTURAL CHARACTERIZATION OF PULSED LASER-DEPOSITED ALN THIN-FILMS ON SEMICONDUCTOR SUBSTRATES

Thin films of aluminum nitride (AlN) have been grown on semiconductor Si (100) substrates using the pulsed laser deposition method. The lase r-deposition parameters and substrate temperature play an important ro le in fabricating high-quality AlN films. The films deposited at highe r temperatures have shown better crystalline properties and also are h ighly oriented perpendicular to the substrate. The films have been cha racterized using X-ray diffraction, scanning electron microscope, and Fourier transform infrared spectroscopic techniques. An atomic force m icroscope was used to obtain three-dimensional topographs of the surfa ces of these films. These maps are useful both for quantitatively char acterizing the roughness of the surfaces and for gaining information a bout the basic mechanisms involved in the film growth process. The har dness as a function of the penetration depth has been measured using t he nano-indentation method. (C) 1997 Elsevier Science S.A.