Recombination activity of threading dislocations in MOVPE-grown AlN/Si {111} films etched by phosphoric acid

Recombination activity of threading dislocations in MOVPE-grown AlN/Si {111} films etched by phosphoric acid

WoS Article

Epitaxial growth of wurtzite AlN films on Si {111} results in 19% lattice misfit, which gives rise to a large density of threading dislocations with different recombination rates of electron-hole pairs. Here, we investigate types and distributions of threading dislocations of the MOVPE-grown 200 nm AlN/Si {111} film, whereby the dislocations are visualized using the technique of wet chemical etching. Atomic force microscopy suggests the existence of four different types of etch pits without any topological differences. Cross-sectional transmission electron microscope studies on etched samples are employed to associate the types of dislocations with the shapes of their etch pits. The recombination activity of individual dislocations was quantified by measuring the electron beam induced current and by correlative measurement of topography, secondary electron imaging, and the electron beam absorbed current. The strongest recombination activity was obtained for the m + c-type (mixed), c-type (screw), and a + c-type (mixed) threading dislocations, whereas the a-type (edge) threading dislocations were nearly recombination-inactive.

Epitaxial growth of wurtzite AlN films on Si {111} results in 19% lattice misfit, which gives rise to a large density of threading dislocations with different recombination rates of electron-hole pairs. Here, we investigate types and distributions of threading dislocations of the MOVPE-grown 200 nm AlN/Si {111} film, whereby the dislocations are visualized using the technique of wet chemical etching. Atomic force microscopy suggests the existence of four different types of etch pits without any topological differences. Cross-sectional transmission electron microscope studies on etched samples are employed to associate the types of dislocations with the shapes of their etch pits. The recombination activity of individual dislocations was quantified by measuring the electron beam induced current and by correlative measurement of topography, secondary electron imaging, and the electron beam absorbed current. The strongest recombination activity was obtained for the m + c-type (mixed), c-type (screw), and a + c-type (mixed) threading dislocations, whereas the a-type (edge) threading dislocations were nearly recombination-inactive.

Epitaxial-Growth; AIN; Threading Dislocations; Electron Microscopy

Epitaxial-Growth; AIN; Threading Dislocations; Electron Microscopy

PONGRÁCZ, J.; VACEK, P.; GRÖGER, R.

2024

21.11.2023

AIP Publishing

MELVILLE

1089-7550

JOURNAL OF APPLIED PHYSICS

134

19

United States of America

11

https://pubs.aip.org/aip/jap/article/134/19/195704/2921456/Recombination-activity-of-threading-dislocations

http://hdl.handle.net/