Cracks in GaN/AlN multiple quantum well structures grown by MBE
Paper in proceeding, 2008

Due to the large lattice constant mismatch and thermal expansion coefficient difference between GaN and AlN, large strain is generated inside the GaN/AlN multiple quantum wells, which causes cracks in the structure. We investigated such cracks by optical microscopy and AFM. The crack density was studied with buffer and cap layer thickness, the number of quantum well periods, and the temperature reduction rate after growth as parameters. It was found that the crack density increased exponentially, with the number of periods above 4. Besides, a very thin, 100 nm, GaN buffer layer and similar to 300 nm GaN cap layer greatly reduced the crack density.


Xinju Liu

Chalmers, Microtechnology and Nanoscience (MC2), Microwave Electronics

T. Aggerstam

Royal Institute of Technology (KTH)

P. Holmstrom

Sophia University

S. Lourdudoss

Royal Institute of Technology (KTH)

Thorvald Andersson

Chalmers, Microtechnology and Nanoscience (MC2), Microwave Electronics

Journal of Physics: Conference Series

17426588 (ISSN) 17426596 (eISSN)

Vol. 100 PART 4 042026

17th Int. Vacuum Congress and 13th Int. Conf. on Surface Science
Stockholm, Sweden,

Subject Categories

Condensed Matter Physics



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