Regensburg 2025 – wissenschaftliches Programm

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HL: Fachverband Halbleiterphysik

HL 29: Poster II

HL 29.55: Poster

Dienstag, 18. März 2025, 18:00–20:00, P1

RPCVD growth of nuclear spin-free 70Ge/28Si70Ge heterostructures on industrial SiGe wafers — •Patrick Daoust, Simone Assali, Anis Attiaoui, Gérard Daligou, Patrick Del Vecchio, Sebastian Koelling, Lu Luo, Nicolas Rotaru, Oussama Moutanabbir, and Éloise Rahier — Department of Engineering Physics, École Polytechnique de Montréal, C.P. 6079, Succ. Centre-Ville, Montréal, Québec, Canada H3C 3A7

The coherence and operation of hole spin qubits in planar Ge heterostructures are both very sensitive to the nuclear spin bath. Therefore, developing nuclear spin-depleted materials is critical to control the performance of these quits. To this end, it is important to eliminate the nuclear spin-full 29Si and 73Ge in the epitaxial Ge/SiGe heterostructures. Our group has recently demonstrated highly crystalline, defect free, isotopically purified (>99.9 at.% 70Ge) nuclear spin-depleted 70Ge quantum well (QW) heterostructures grown in a reduced pressure CVD using purified precursors (>99.9 at.% 70GeH4 and >99.99 at.% 28SiH4) on in situ grown reversed graded SiGe buffers [1]. However, this growth protocol is not efficient and consumes significantly these purified precursors. Herein, we show that the growth of 70Ge QW can be achieved on industrial SiGe wafers thus optimizing the usage of precursors, preventing any background contamination from natural precursors, and yielding highly purified 70Ge/28Si70Ge heterostructures.

Keywords: CVD; spin qubit; heterostructure; isotopically purified