We demonstrate a 12 quantum dot device fabricated on an undoped Si/SiGe
heterostructure as a proof-of-concept for a scalable, linear gate architecture
for semiconductor quantum dots. The device consists of 9 quantum dots in a
linear array and 3 single quantum dot charge sensors. We show reproducible
single quantum dot charging and orbital energies, with standard deviations less
than 20% relative to the mean across the 9 dot array. The single quantum dot
charge sensors have a charge sensitivity of 8.2 x 10^{-4} e/root(Hz) and allow
the investigation of real-time charge dynamics. As a demonstration of the
versatility of this device, we use single-shot readout to measure a spin
relaxation time T1 = 170 ms at a magnetic field B = 1 T. By reconfiguring the
device, we form two capacitively coupled double quantum dots and extract a
mutual charging energy of 200 microeV, which indicates that 50 GHz two-qubit
gate operation speeds are feasible
