The effect of dislocation-related V-shaped pits preparation on the strain of AlN templates

• Published in: Thin solid films 2021-07, Vol.730, p.138706, Article 138706
• Main Authors: Zhou, Xingyu, Chen, Yiren, Zhang, Zhiwei, Miao, Guoqing, Jiang, Hong, Li, Zhiming, Song, Hang
• Format: Article
• Language: English
• Subjects: Aluminum nitride template; Dislocation defects; Epitaxial growth; Metal-organic chemical vapor deposition; Microstructure; Stress regulation; Wet etching
• ISSN: 0040-6090; 1879-2731
• DOI: 10.1016/j.tsf.2021.138706

•Wet etching and epitaxial overgrowth destroy dislocations in heteroepitaxial AlN.•The effect of dislocation-related V-shaped pits on the strain of AlN is studied.•Developing a mask-free lateral epitaxy of AlN template based on V-shaped pits. Herein, the dislocation defects of an aluminum nitride (AlN) template heteroepitaxially grown by metal-organic chemical vapor deposition are exposed by phosphoric acid etching. The effect of dislocation-related V-shaped pits preparation on the strain of AlN epilayer is intensively studied. The results show that the dislocation defect etching leads to a strain gradient elongating along the growth direction of AlN and alleviates its initial tensile strain. Through a secondary epitaxy on the dislocation-etched AlN, it further reveals that the strain evolves into compressive strain state accompanied by surface cracking inhibition. It provides an effective way of stress regulation by dislocation-related etching and can be developed as a mask-free lateral epitaxial growth technique for high-performance AlN template preparation.