Germanium wafers for strained quantum wells with low disorder

We grow strained Ge/SiGe heterostructures by reduced-pressure chemical vapor deposition on 100 mm Ge wafers. The use of Ge wafers as substrates for epitaxy enables high-quality Ge-rich SiGe strain-relaxed buffers with a threading dislocation density of (6 +/- 1) x 10(5) cm(-2), nearly an order of magnitude improvement compared to control strain-relaxed buffers on Si wafers. The associated reduction in short-range scattering allows for a drastic improvement of the disorder properties of the two-dimensional hole gas, measured in several Ge/SiGe heterostructure field-effect transistors. We measure an average low percolation density of (1:22 +/- 0:03) x 10(10) cm(-2) and an average maximum mobility of (3:4 +/- 0:1) x 10(6) cm(2)/Vs and quantum mobility of (8:4 +/- 0:5) x 10(4) cm(2)/Vs when the hole density in the quantum well is saturated to (1:65 +/- 0:02) x 10(11) cm(-2). We anticipate immediate application of these heterostructures for next-generation, higher-performance Ge spin-qubits, and their integration into larger quantum processors.