Fast nanoscale imaging of strain in a multi-segment heterostructured nanowire with 2D Bragg ptychography

Susanna Hammarberg; Dmitry Dzhigaev; Lucas A B Marçal; Vilgailė Dagytė; Alexander Björling; Magnus T Borgström; Jesper Wallentin

doi:10.1107/S1600576723010403

Fast nanoscale imaging of strain in a multi-segment heterostructured nanowire with 2D Bragg ptychography

J Appl Crystallogr. 2024 Feb 1;57(Pt 1):60-70. doi: 10.1107/S1600576723010403.

Authors

Susanna Hammarberg¹, Dmitry Dzhigaev¹, Lucas A B Marçal^{1

2}, Vilgailė Dagytė³, Alexander Björling², Magnus T Borgström³, Jesper Wallentin¹

Affiliations

¹ Synchrotron Radiation Research and NanoLund, Lund University, Box 118, Lund 22100, Sweden.
² MAX IV Laboratory, Lund University, Lund 22100, Sweden.
³ Solid State Physics and NanoLund, Lund University, Box 118, Lund 22100, Sweden.

Abstract

Developing semiconductor devices requires a fast and reliable source of strain information with high spatial resolution and strain sensitivity. This work investigates the strain in an axially heterostructured 180 nm-diameter GaInP nanowire with InP segments of varying lengths down to 9 nm, simultaneously probing both materials. Scanning X-ray diffraction (XRD) is compared with Bragg projection ptychography (BPP), a fast single-projection method. BPP offers a sufficient spatial resolution to reveal fine details within the largest segments, unlike scanning XRD. The spatial resolution affects the quantitative accuracy of the strain maps, where BPP shows much-improved agreement with an elastic 3D finite element model compared with scanning XRD. The sensitivity of BPP to small deviations from the Bragg condition is systematically investigated. The experimental confirmation of the model suggests that the large lattice mismatch of 1.52% is accommodated without defects.

Keywords: Bragg projection ptychography; III–V materials; X-ray imaging; nanowires.

Grants and funding

This research was funded by the European Research Council (ERC) under the European Union’s Horizon 2020 research and innovation program (grant agreement No. 801847 awarded to JW). This project also has funding support from the Olle Engkvist foundation (awarded to JW), NanoLund (awarded to JW and MB), Marie Skłodowska Curie Actions Cofund (project No. INCA 600398 awarded to JW) and the Swedish Research Council (grant No. 2015-00331). The authors acknowledge MAX IV Laboratory for beam time on the NanoMAX beamline (proposal No. 20200567). Research conducted at MAX IV, a Swedish national user facility, is supported by Vetenskapsrådet (Swedish Research Council) (contract No. 2018–07152 awarded to Lund University), VINNOVA (Swedish Governmental Agency for Innovation Systems) (contract 2018-04969 awarded to Lund University) and Svenska Forskningsrådet Formas (contract No. 2019–02496 awarded to Lund University).