A comparative study of defect formation in GaAs nanocrystals selectively grown on nanopatterned and flat Si(001) substrates

作者：Kozak Roksolana^*; Prieto Ivan; Dasilva Yadira Arroyo Rojas; Erni Rolf; von Kaenel Hans; Bona Gian Luca; Rossell Marta D

来源：Micron, 2018, 113: 83-90.

DOI：10.1016/j.micron.2018.06.018

• Crystalline defects
• Defect density analysis
• HAADF-STEM
• EDX
• Tomography
• GaAs
• Si nanostructures

Crystal defects present in GaAs nanocrystals similar to 15-50 nm in diameter and grown by metal organic vapor phase epitaxy on top of two different nanopatterned Si(001) substrates (nanopillars and nanotips with similar to 40-80 nm openings embedded in a SiO2 matrix) and on a planar substrate, have been investigated by means of atomic resolution aberration-corrected scanning transmission electron microscopy. Conditions of their formation are discussed. The defect analysis of the three GaAs/Si systems reveals a higher defect density in the GaAs crystals grown on nanopillars as compared to those grown on nanotips and the planar substrate, possibly concomitant to the atomic-scale irregularities identified at the patterned Si(001) nanopillars. It is concluded that the misfit strain in the GaAs nanocrystals is fully plastically relaxed while no noticeable substrate compliance effects are observed on any of the studied substrates.

• 出版日期2018-10