The effect of growth parameters on the Mg acceptor in InxGa1-xN:Mg and AlxGa1-xN:Mg

• Published in: Physica status solidi. C Vol. 11; no. 3-4; pp. 594 - 597
• Main Authors: Zvanut, M. E., Willoughby, W. R., Sunay, U. R., Koleske, D. D., Allerman, A. A., Wang, Ke, Araki, Tsutomu, Nanishi, Yasushi
• Format: Journal Article
• Language: English
• Published: Berlin WILEY-VCH Verlag 01.04.2014; WILEY‐VCH Verlag; Wiley Subscription Services, Inc
• Subjects: AlGaN; EPR; InGaN
• ISSN: 1862-6351; 1610-1642
• DOI: 10.1002/pssc.201300515

InxGa1–xN and AlxGa1–xN alloys are used in many optoelectronic applications due to their tunable band gap, but p‐type doping remains a challenge. To better understand the Mg acceptor in nitride alloys, we investigate the effects of In or Al mole fraction, growth temperature and sample thickness on the amount of un‐ionized (neutral) Mg using electron paramagnetic resonance (EPR) spectroscopy. The results show that neither temperature nor thickness effects the concentration of the neutral Mg‐related acceptor defects; however, the mole fraction of metal, In or Al, alters the behavior of the dopant. For InxGa1–xN, a broadening of the EPR linewidth is shown to be directly related to the presence of a nearby In and is consistent with a lowering of the acceptor level. Incorporation of Al into GaN, on the other hand, produces a systematic decrease in the concentration of neutral Mg‐related acceptors as the amount of Al increases. Earlier studies indicate that the reduction is caused by incomplete hydrogen removal from the acceptor impurity. (© 2014 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)