Basic properties of ternary group III nitride compound semiconductor non-polar surfaces
Final Report Abstract
Semiconductor devices based on wurtzite structure group III-nitrides require ternary (Al,Ga,In)N compounds in order to achieve the desired materials properties. However, these ternary alloys are not lattice matched to trhe existing substrates with the exception of Al0.81In0.19N/GaN, which is almost matching. Furthermore, growth on non-polar surfaces of ternary nitrides offers the prospect to grow polarization free heterojunctions. Since the growth is directly affected by the surface properties, the aim of the current project was to investigate the basic electronic and structural properties of non-polar surfaces of ternary nitride semiconductors. During the project the composition dependent changes of the intrinsic surfaces states were determined for (Al,Ga)N, the doping dependence of the interplay of extrinsic and intrinsic states leading to a Fermi-level pinning, and the effect of hydroxylation during air exposure. In addition, we developed a methodology to determine polarization changes and electron affinity changes quantitatively at heterointerfaces, based on the calibration of electron holography in transmission electron microscopy. This was demonstrated for Al,Ga)N/GaN and (In,Ga)N/(Al,Ga)N interfaces, where an anomalous strain relaxation was correlated with an polarization change minimization.
Publications
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Dislocation bending in GaN/step-graded (Al,Ga)N/AlN buffer layers on Si(111) investigated by STM and STEM. Philosophical Magazine, 98(34), 3072-3085.
Zhang, Lei; Portz, Verena; Schnedler, Michael; Jin, Lei; Wang, Yuhan; Hao, Xiaopeng; Eisele, Holger; Dunin-Borkowski, Rafal E. & Ebert, Philipp
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Interplay of anomalous strain relaxation and minimization of polarization changes at nitride semiconductor heterointerfaces. Physical Review B, 102(24).
Wang, Y.; Schnedler, M.; Lan, Q.; Zheng, F.; Freter, L.; Lu, Y.; Breuer, U.; Eisele, H.; Carlin, J.-F.; Butté, R.; Grandjean, N.; Dunin-Borkowski, R. E. & Ebert, Ph.
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Interplay of intrinsic and extrinsic states in pinning and passivation of m-plane facets of GaN n-p-n junctions. Journal of Applied Physics, 128(18).
Freter, L.; Wang, Y.; Schnedler, M.; Carlin, J.-F.; Butté, R.; Grandjean, N.; Eisele, H.; Dunin-Borkowski, R. E. & Ebert, Ph.
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Quantitative investigation of group III-nitride interfaces by a combination of scanning tunneling microscopy and off-axis electron holography. Schriften des Forschungszentrums Jülich, Reihe Information Band 64 (2021). Dissertation RWTH Aachen University 2020, ISBN: 978-3-95806-534-5,
Yuhan Wang
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Surface states and Fermi-level pinning on non-polar binary and ternary (Al,Ga)N surfaces. Schriften des Forschungszentrums Jülich, Reihe Information Band 84 (2022). Dissertation RWTH Aachen University 2022, ISBN 978-3-95806-644-1
Lars Freter
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Rastertunnelmikroskopie an Querschnittsflächen und modifizierten Oberflächen von III-V-Verbindungshalbleitern. Dissertation TU-Berlin (2023)
Wjatscheslav Martyanov
