Quality-Improved GaN Epitaxial Layers Grown on Striped Patterned Sapphire Substrates Ablated by Femtosecond Laser

In this work, we propose a new approach to create striped patterned sapphire substrate (PSS) under the circumstance that grooved patterned sapphire substrate technology exhibits more potential to reduce dislocation density in GaN (gallium nitride) epilayers. The striped grooves of patterned sapphire...

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Bibliographic Details
Main Authors: Yichao Xu, Jun Zou, Xiaoyan Lin, Wenjuan Wu, Wenbo Li, Bobo Yang, Mingming Shi
Format: Article
Language:English
Published: MDPI AG 2018-10-01
Series:Applied Sciences
Subjects:
Online Access:http://www.mdpi.com/2076-3417/8/10/1842
Description
Summary:In this work, we propose a new approach to create striped patterned sapphire substrate (PSS) under the circumstance that grooved patterned sapphire substrate technology exhibits more potential to reduce dislocation density in GaN (gallium nitride) epilayers. The striped grooves of patterned sapphire substrate are ablated by femtosecond laser. After the process of metal-organic chemical vapor deposition (MOCVD) method, the c-plane GaN epitaxial layers grown on striped PSS have larger crystallite size, which brings much less crystal boundary. There is much less compressive stress between the GaN crystals which improves the smoothness and compactness of GaN epilayers. This result demonstrates a significant improvement in the crystallinity of the c-plane GaN epitaxial layers grown on striped PSS.
ISSN:2076-3417