Epitaxial growth of single-crystalline AIN films on tungsten substrates

The authors have grown single-crystalline AlN(0001) films on W(110) substrates with an in-plane alignment AlN[11-20] parallel to W[001] at temperatures ranging from 450 to 600 degrees C by pulsed laser deposition. These AlN films have a clear sixfold symmetry without 30 S rotational domains. When AlN films are grown at 450 degrees C, the interfacial reaction between AlN and W (110) is fully suppressed and a flat surface with a root-mean-square value as low as 0.20 nm for AlN films is obtained. These single-crystalline AlN films grown on W (110) open a good opportunity for the high performance film bulk acoustic wave resonators of the next generation. (c) 2006 American Institute of Physics.