Epitaxial growth of AlN films on single-crystalline Ta substrates

摘要

We have demonstrated the first epitaxial growth of AIN films on single-crystalline Ta substrates by the use of a low-temperature growth technique based on pulsed laser deposition (PLD). Although previous AIN films grown on Ta(100) and (111) substrates have exhibited quite poor crystallinity, an epitaxial AIN(0001) film with an in-plane epitaxial relationship of AIN[11 (2) over bar0]//Ta[001] has been obtained on a Ta(110) substrate at a growth temperature of 450 degrees C. We found that the full-width at half-maximum values for the crystal orientation distribution in the tilt and twist directions of the AIN film were 0.37 degrees and 0.41 degrees, respectively. Grazing-incidence X-ray reflection (GIXR) and X-ray photoelectron spectroscopy (XPS) measurements have revealed that the AIN/Ta heterointerface is quite abrupt, and that its abruptness remains unchanged even after annealing at 1000 degrees C. (C) 2007 Elsevier Inc. All rights reserved.