کد مقاله | کد نشریه | سال انتشار | مقاله انگلیسی | نسخه تمام متن |
---|---|---|---|---|
1791475 | 1524469 | 2012 | 4 صفحه PDF | دانلود رایگان |

AlN layers were grown on (0001) sapphire substrates by hydride vapor phase epitaxy (HVPE) at 1100 °C with a source gas supply sequence of (1) NH3 preflow or (2) AlCl3 preflow. An Al-polarity AlN layer without inclusion of a N-polarity region was grown when AlCl3 was preflown to the sapphire surface prior to AlN growth, while N- and Al-polarity regions were both present in the same AlN layer when NH3 was preflown, since growth was performed on a nitrided sapphire surface. Compared with the AlN layers grown with NH3 preflow, the Al-polarity AlN layers grown with AlCl3 preflow had improved crystalline structural quality, a low concentration of oxygen impurity, and a photoabsorption edge energy of 6.08 eV, which is close to an ideal value. Therefore, the source gas supply sequence has a significant influence on the growth of AlN layers on (0001) sapphire substrates. Thus, preflow of AlCl3 gas to a sapphire surface prior to AlN growth is a key process for high crystalline quality AlN layer growth with uniform Al-polarity on (0001) sapphire substrates by HVPE.
► When AlN is grown with NH3 preflow, both N- and Al-polarity AlN regions are present.
► When AlN is grown with AlCl3 preflow, Al-polarity AlN without incorporation of N-polarity regions can be grown.
► The AlN layer grown with AlCl3 preflow had higher crystalline quality than NH3 preflow.
► AlCl3 preflow prior to HVPE growth of AlN is quite effective for growing high-quality AlN layers on (0001) sapphire substrates.
Journal: Journal of Crystal Growth - Volume 360, 1 December 2012, Pages 197–200