Highly-oriented A1N Thin Films on Si(100) Substrates by Pulsed Laser Deposition

Highly crystalline quality A1N thin films were successfully grown on Ti0.8Al0.2N/TiNbuffered p-Si(100) substrates by pulsed laser deposition (laser source: KrF). X-ray diffraction (XRD) and reflective high energy electron diffraction (RHEED) were employed to characterize the as-grown films. The results show that A1N thin films are (001) oriented and grown with 2D layer growth mode. The growth modes of thin films rely on the kinds of buffer layers: A1N thin films on Si wafers or MgO/Si substrates are 3D island grown; whereas those on Ti0.8Al0.2N/TiN/Si substrates are 2D layer grown. In addition, the laser energy density has considerable effects on the crystalline quality of A1N thin films: over high energy leads to rough surface and big particles. The partial nitrogen pressure can make A1N thin films (100) orientation instead of (001) orientation.