GaN Growth on Novel Lattice-Matching Substrate: Tilted M-Plane Sapphire

✍ Scribed by Matsuoka, T. ;Hagiwara, E.

• Publisher: John Wiley and Sons
• Year: 2001
• Tongue: English
• Weight: 139 KB
• Volume: 188
• Category: Article
• ISSN: 0031-8965
• DOI: 10.1002/1521-396x(200112)188:2<485::aid-pssa485>3.0.co;2-#

✦ Synopsis

As a novel substrate, nearly lattice-matched to GaN and coincident with its crystallographic symmetry, M-plane sapphire is shown to be promising by evaluating the characteristics of GaN epitaxial films grown on this substrate using a two-step growth process. For M-plane sapphire, the tilt of a wafer surface from the M-plane around the c-axis is found to be important in obtaining highquality GaN. Tilt angles of 15 and 20 make possible the growth of single-crystal GaN. Singlecrystal GaN grown on the surface tilted 15 from the M-plane has a very smooth surface and shows the pure near-band-edge emission with strong intensity in photoluminescence. The dislocation density in this GaN is 50% higher than in GaN grown on C-plane. It is expected that GaN quality can be improved by optimizing the tilt angle and employing a growth condition suitable for the tilted surface.