Author(s): Feng, Q (Feng, Qiong); Ai, YJ (Ai, Yujie); Liu, Z (Liu, Zhe); Yu, ZG (Yu, Zhiguo); Yang, K (Yang, Kun); Dong, BY (Dong, Boyu); Guo, BL (Guo, Bingliang); Zhang, Y (Zhang, Yun)
Source: SUPERLATTICES AND MICROSTRUCTURES Volume: 141 Article Number: 106493 DOI: 10.1016/j.spmi.2020.106493 Published: MAY 2020
Abstract: (11-22)-oriented AlN films are sputtered on m-plane sapphire substrates at different temperatures. With an optimized sputtering temperature of 800 degrees C and high-temperature annealing at 1600 degrees C, the full widths at half maximum (FWHMs) of X-ray diffraction of AlN are 0.186 degrees and 0.243 degrees along [11-23] AlN and [1-100](AlN). The annealed AlN shows smooth surface morphology with a roughness of 0.425 nm. Convergent beam electron diffraction patterns display that the annealed AlN (11-22) film is grown with Al-face sense polarity rather than mixed polarity in c-plane sputtered AlN, which may result from less oxygen in the AlN/sapphire interface. Threading dislocations with a density of 7.5 x 10(9) cm(-2) and stacking faults with a density of 1.1 x 10(5) cm(-1) are identified in the transmission electron microscopy cross-sectional images. The crystal quality of AlN in this work is attractive for growth and fabrication of AlN or AlGaN-based semipolar devices.
Accession Number: WOS:000528835100015
ISSN: 0749-6036
Full Text: https://www.sciencedirect.com/science/article/pii/S0749603620300641?via%3Dihub