Ge/SiGe Quantum Wells: Material for the Post-Moore Era

This dissertation demonstrates high-quality germanium quantum wells on a 200 mm silicon wafer platform, enabling novel device possibilities.Partnering with a commercial silicongermanium epitaxy supplier, we obtained shallow, undoped germanium quantum wells with high-crystalline quality, confirmed through x-ray diffraction, secondary ion mass spectroscopy, high-resolution scanning transmission electron microscopy, and energy dispersive x-ray spectroscopy.Hall bar devices fabricated on single quantum wells revealed that surface preparation can tune transport properties while maintaining peak mobilities around 10 5 cm 2 V -1 s -1 .Manganese-germanide spintronic contacts were integrated via solidstate reaction, with contact quality assessed through Schottky diodes, transfer length method devices, and Hall bars.These findings highlight the potential for advanced spintronic and quantum devices, emphasizing the importance of surface preparation and integration techniques in optimizing device performance.v