4H-polytype AlN grown on 4H-SiC(11(2)over-bar0) substrate by polytype replication

4H-polytype AlN has been grown on a 4H-SiC substrate with the (11 (2) over bar0) face via plasma-assisted molecular-beam epitaxy. The microscopic structure of the AlN/4H-SiC interface was examined using high-resolution transmission electron microscopy, and the polytype replication of the 4H structure from the 4H-SiC(11 (2) over bar0) substrate was evidently confirmed. The x-ray rocking curve of (11 (2) over bar0) diffraction for the single crystalline 4H-AlN epilayer exhibited a very small linewidth of 90 arc sec, suggesting noticeably small tilting around the [11 (2) over bar0] direction. The excellent crystalline quality is probably owing to the polytype matching between the 4H-AlN epilayer and the 4H-SiC substrate, which resulted in remarkable reduction of defects at the interface. (C) 2003 American Institute of Physics.