Berlin 2024 – scientific programme

Parts | Days | Selection | Search | Updates | Downloads | Help

HL: Fachverband Halbleiterphysik

HL 14: Poster II

HL 14.5: Poster

Monday, March 18, 2024, 15:00–18:00, Poster F

Assessing the alignment accuracy of state-of-the-art deterministic fabrication methods for single quantum dot devices — Abdulmalik Madigawa¹, •Jan Donges², Benedek Gaal¹, Shulun Li^2,3,4, Hanqing Liu^3,4, Deyan Dai^3,4, Xiangbin Su^3,4, Xiangjun Shang^3,4, Haiqiao Ni^3,4, Johannes Schall², Sven Rodt², Zhichuan Niu^3,4, Niels Gregersen¹, Stephan Reitzenstein², and Battulga Munkhbat¹ — ¹TU Denmark — ²TU Berlin — ³Institute of Semiconductors Beijing — ⁴University of Chinese Academy of Sciences Beijing

The realization of efficient quantum light sources relies on the integration of self-assembled quantum dots (QDs) into photonic nanostructures with high spatial positioning accuracy. In this work, we present a comprehensive investigation of the QD position accuracy, obtained using two markerbased QD positioning techniques, photoluminescence (PL) and cathodoluminescence (CL) imaging, as well as using a marker-free in-situ electron beam lithography (in-situ EBL) technique. We employ four PL imaging configurations with three different image processing approaches and compare them with CL imaging. We fabricate circular mesa structures based on the obtained QD coordinates from both PL and CL image processing to evaluate the final positioning accuracy. We discuss the possible causes of the observed offsets, which are significantly larger than the QD localization uncertainty obtained from simply imaging the QD light emission from an unstructured wafer.

Keywords: Quantum dot; deterministic fabrication; single photon devices