Polarity Control by Inversion Domain Suppression in N-Polar III-Nitride Heterostructures

Autor: Hengfang Zhang, Ingemar Persson, Jr.-Tai Chen, Alexis Papamichail, Dat Q. Tran, Per O. Å. Persson, Plamen P. Paskov, Vanya Darakchieva
Rok vydání: 2023
Předmět:
Zdroj: Crystal Growth & Design. 23:1049-1056
ISSN: 1528-7505
1528-7483
DOI: 10.1021/acs.cgd.2c01199
Popis: Nitrogen-polar III-nitride heterostructures offer advantages over metal-polar structures in high frequency and high power applications. However, polarity control in III-nitrides is difficult to achieve as a result of unintentional polarity inversion domains (IDs). Herein, we present a comprehensive structural investigation with both atomic detail and thermodynamic analysis of the polarity evolution in low- and high-temperature AlN layers on on-axis and 4$^{\circ}$ off-axis Carbon-face 4H-SiC (000$\bar{1}$) grown by hot-wall metal organic chemical vapor deposition. A polarity control strategy has been developed by variation of thermodynamic Al supersaturation and substrate misorientation angle in order to achieve desired growth mode and polarity. We demonstrate that IDs are totally suppressed for high-temperature AlN nucleation layers when step-flow growth mode is achieved at the off-axis. We employ this approach to demonstrate high quality N-polar epitaxial AlGaN/GaN/AlN heterostructures.
Comment: 9 pages, 6 figures
Databáze: OpenAIRE