Study of Nucleation and Early Growth of Diamond on GaN

0434718 - FZÚ 2015 CZ eng A - Abstract
Ižák, Tibor - Babchenko, Oleg - Potocký, Štěpán - Vanko, G. - Vojs, Marian - Kromka, Alexander
Study of Nucleation and Early Growth of Diamond on GaN.
NANOCON 2014 Conference Proceedings. Ostrava: Tanger, 2014. ISBN 978-80-87294-55-0.
[International Conference NANOCON /6./. 05.11.2014-07.11.2014, Brno]
R&D Projects: GA ČR(CZ) GP14-16549P
Institutional support: RVO:68378271
Keywords : diamond films * MWCVD * GaN membranes * c-HEMT * heterostructures
Subject RIV: BM - Solid Matter Physics ; Magnetism

In this study we investigate the diamond growth on GaN substrates by microwave plasma CVD. We show that using a proper gas mixture is crucial a technological factor to keep the functionality of GaN HEMT devices. Addition of CO2 and N2 to CH4/H2 gas mixture is used to minimize damaging of GaN substrate. We also found that the gas mixture control the diamond morphology from nano- to polycrystalline character. Simultaneous study focuses on the diamond growth on GaN membranes. In this case, diamond nucleation is the most limiting technological step due to low mechanical stability of GaN membranes. We observed that standard nucleation techniques (ultrasonic seeding or bias enhanced nucleation) caused cracking of the membranes or not appropriate nucleation efficiency in the Z-depth of structures. Therefore we implemented PVA polymer consisting of diamond powder as seeding composite which resulted in a successful growth of diamond thin film.
Permanent Link: http://hdl.handle.net/11104/0238689