We have grown AIN films by pulsed laser deposition (PLD) on sapphire (0001) substrates nitrided in a carbon-saturated N2-CO gas mixture and investigated their structural properties. It is found that AIN epilayers prepared on as-grown N2-CO nitrided sapphire consist of two domains whose (1010)AIN directions are rotated by approximately ±0.5° from the (1120)sapphire directions. On the other hand, a nitrogen radical treatment of the as-grown nitrided substrate makes it possible to eliminate one of the domains without any degradation in crystalline quality. The full width at half maximum values of X-ray rocking curves for the 0002 and 1012 diffractions of the AlN film are as low as 27 and 590arcsec, respectively.
ASJC Scopus subject areas
- Physics and Astronomy(all)