Specific features of N[H.sub.3] and plasma-assisted MBE in the fabrication of III--N HEMT heterostructures

• Published in: Semiconductors (Woodbury, N.Y.) p. 92
• Main Authors: Alexeev, A.N, Krasovitsky, D.M, Petrov, S.I, Chaly, V.P, Mamaev, V.V, Sidorov, V.G
• Format: Journal Article
• Language: English
• Published: Springer 01.01.2015
• Subjects: Ammonia; Epitaxy; Liquors
• DOI: 10.1134/S1063782615010029
• ISSN: 1063-7826

The specific features of how nitride HEMT heterostructures are produced by NH3 and plasma-assisted (PA) molecular-beam epitaxy (MBE) are considered. It is shown that the use of high-temperature AlN/AlGaN buffer layers grown with ammonia at extremely high temperatures (up to 1150°C) can drastically improve the structural perfection of the active GaN layers and reduce the dislocation density in these layers to values of 9 x [10.sup.8]-1 x [10.sup.9] [cm.sup.-2]. The use of buffer layers of this kind makes it possible to obtain high-quality GaN/AlGaN heterostructures by both methods. At the same time, in contrast to ammonia MBE which is difficult to apply at T< 500°C (because of the low efficiency of ammonia decomposition), PA MBE is rather effective at low temperatures, e.g., for the growth of InAIN layers lattice-matched with GaN. The results obtained in the MBE growth of AlN/AlGaN/GaN/InAIN heterostructures by both PA-MBE and NH3-MBE with an extremely high ammonia flux are demonstrated. DOI: 10.1134/S1063782615010029