Understanding Interfaces in AlScN/GaN Heterostructures - INSA CENTRE VAL DE LOIRE Accéder directement au contenu
Article Dans Une Revue Advanced Functional Materials Année : 2024

Understanding Interfaces in AlScN/GaN Heterostructures

Résumé

Abstract Aluminum scandium nitride barrier layers increase the available sheet charge carrier density in gallium nitride‐based high‐electron‐mobility transistors and boost the output power of high‐frequency amplifiers and high voltage switches. Growth of AlScN by metal‐organic chemical vapor deposition is challenging due to the low vapor pressure of the conventional Sc precursor Cp 3 Sc, which induces low growth rates of AlScN and leads to thermally‐induced AlScN/GaN‐interface degradation. In this work, novel Sc precursors are employed to reduce the thermal budget by increasing the growth rate of the AlScN layer. The AlScN/GaN interfaces are investigated by high‐resolution X‐ray diffraction, high‐resolution transmission electron microscopy, time‐of‐flight secondary ion mass spectrometry, capacitance–voltage, current–voltage and temperature‐dependent Hall measurements. Linearly graded interlayers with strain‐induced stacking faults, edge, and screw dislocations form at the AlScN/GaN interface at growth rates of 0.015 nms −1 . Growth rates of 0.034 nms −1 and higher allow for abrupt interfaces, but a compositional grading in the barrier remains. Homogeneous barrier layers can be achieved at growth rates of 0.067 nms −1 or by growing an AlN interlayer. The electrical properties of the heterostructures are sensitive to Sc accumulations at the cap/barrier interface, residual impurities from precursor synthesis, and surface roughness. This study paves the way for high‐performing devices.
Fichier principal
Vignette du fichier
Adv Funct Materials - 2024 - Streicher - Understanding Interfaces in AlScN GaN Heterostructures (1).pdf (4.2 Mo) Télécharger le fichier
Origine : Publication financée par une institution
licence : CC BY - Paternité

Dates et versions

hal-04579433 , version 1 (17-05-2024)

Licence

Paternité

Identifiants

Citer

Isabel Streicher, Stefano Leone, Meiling Zhang, Taoufik Slimani Tlemcani, Micka Bah, et al.. Understanding Interfaces in AlScN/GaN Heterostructures. Advanced Functional Materials, 2024, ⟨10.1002/adfm.202403027⟩. ⟨hal-04579433⟩
0 Consultations
0 Téléchargements

Altmetric

Partager

Gmail Facebook X LinkedIn More