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3D GaN Fins as a Versatile Platform for a‐Plane‐Based Devices
Author(s) -
Hartmann Jana,
Manglano Clavero Irene,
Nicolai Lars,
Margenfeld Christoph,
Spende Hendrik,
Ledig Johannes,
Zhou Hao,
Steib Frederik,
Jaros Angelina,
Avramescu Adrian,
Strassburg Martin,
Trampert Achim,
Wehmann HergoHeinrich,
Lugauer HansJürgen,
Voss Tobias,
Waag Andreas
Publication year - 2019
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.201800477
Subject(s) - materials science , sapphire , dislocation , optoelectronics , epitaxy , quenching (fluorescence) , wide bandgap semiconductor , vapor phase , layer (electronics) , nanotechnology , composite material , optics , fluorescence , laser , physics , thermodynamics
GaN fins on GaN‐on‐sapphire templates are fabricated by continuous mode selective area metalorganic vapor phase epitaxy. The fins exhibit high aspect ratios and smooth nonpolar a‐plane sidewalls with an ultra‐low threading dislocation density of a few 10 5 cm −2 making them ideally suited for optoelectronic to electronic applications. A detailed analysis of the inner structure of GaN fins is provided by the help of marker layer experiments and correlation of results from fins fabricated under different growth conditions, leading to the development of a growth model to explain the final geometry and optical as well as electrical properties of these high aspect ratio fins. Distinctly different material properties for the central and outer parts of the fins are detected. Whereas the outer sidewalls represent high quality GaN surfaces with very low defect densities, a strong quenching of near band edge emission (NBE) in the central part of the fins is accompanied by heavy compensation of free electrons. A possible explanation is the incorporation of excessive point defects, like intrinsic defects or carbon impurity. The sidewall regions, however, prove to be highly suitable for device applications due to their strong NBE emission, low dislocation density, and high free carrier concentration.