Determination of stress, strain, and elemental distribution within In(Ga)As quantum dots embedded in GaAs using advanced transmission electron microscopy

Full text: Download

Publisher: AIP Publishing

Preprint: archiving allowed. Upload

Postprint: archiving allowed. Upload

Published version: archiving restricted: Upload

Policy details (opens in a new window). Data provided by SHERPA/RoMEO
Abstract
Non-truncated pyramidal In(Ga)As quantum dots (QDs) embedded in GaAs were obtained by a combination of low temperature/high rate GaAs covering of InAs QDs. We use advanced transmission electron microscopy to study the composition and mechanics of the objects. Results from the core region of a sliced QD, and from an entire object, are consistent and complementary allowing the development of accurate models describing the 3D shape, chemical distribution, elastic strains and stresses in the QD, wetting layer, and matrix. The measured structure develops an extremely compressive apex, reaching a vertical stress of �8 GPa and horizontal stress of �6.2 GPa.