Premium
Thickness and growth condition dependence of crystallinity in semipolar (20–21) GaN films grown on (22–43) patterned sapphire substrates
Author(s) -
Takeuchi Shotaro,
Uchiyama Toshiro,
Arauchi Takuji,
Hashimoto Yasuhiro,
Nakamura Yoshiaki,
Yamane Keisuke,
Okada Narihito,
Tadatomo Kazuyuki,
Sakai Akira
Publication year - 2015
Publication title -
physica status solidi (b)
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.51
H-Index - 109
eISSN - 1521-3951
pISSN - 0370-1972
DOI - 10.1002/pssb.201451562
Subject(s) - sapphire , materials science , crystallinity , curvature , lattice (music) , stacking , basal plane , lattice plane , optoelectronics , anisotropy , diffraction , optics , crystallography , composite material , chemistry , laser , geometry , reciprocal lattice , physics , mathematics , organic chemistry , acoustics
We have investigated the crystalline morphology such as lattice plane curvature and lattice plane tilting in (20–21) GaN films on (22–43) patterned sapphire substrates (PSS) by using X‐ray rocking curve (XRC) measurements. The results of the symmetric XRC for the GaN (20–21) plane showed anisotropic lattice plane curvature between the [−1014] and [−12–10] directions. This is due to the large difference of the thermal expansion coefficient in the [0001] direction between GaN and sapphire. From the results of asymmetric XRC for the GaN (20–22) and (12–31) diffractions, it is found that lattice plane tilting is highly dependent on the film thickness and the growth condition. The −c‐plane‐suppressed growth process with tuning the V/III ratio for the (20–21) GaN films on the (22–43) PSS is very effective to suppress the generation of basal plane stacking faults as confirmed by TEM analysis.