Growth and characterization of Si/SiGe heterostructures towards scalable qubit architecture

Strained Si/SiGe Quantum Well (QW) structures are a promising material system for the realization of spin qubits based on spatially confined electrons. A major advantage for Si-based structures is their compatibility with mature Si-CMOS technology, providing high scalability. In this study we show a first step towards determining the relationship between the material properties (e.g. interface roughness and defect density) and qubit performance of these structures. In order to discuss the influence of the material properties of the QW, tensile strained Si QW embedded in Si_0.7 Ge_0.3 layers with different types of SiGe buffer layers are fabricated on 200 mm Si substrates. The material properties are characterized by various methods (X-Ray Diffraction, Secondary Ion Mass Spectrometry, Scanning Transmission Electron Microscopy).