  We introduce a silicon metal-oxide-semiconductor quantum dot architecture
based on a single polysilicon gate stack. The elementary structure consists of
two enhancement gates separated spatially by a gap, one gate forming a
reservoir and the other a quantum dot. We demonstrate, in three devices based
on two different versions of this elementary structure, that a wide range of
tunnel rates is attainable while maintaining single-electron occupation. A
characteristic change in slope of the charge transitions as a function of the
reservoir gate voltage, attributed to screening from charges in the reservoir,
is observed in all devices, and is expected to play a role in the sizable
tuning orthogonality of the split enhancement gate structure. The all-silicon
process is expected to minimize strain gradients from electrode thermal
mismatch, while the single gate layer should avoid issues related to overlayers
(e.g., additional dielectric charge noise) and help improve yield. Finally,
reservoir gate control of the tunnel barrier has implications for
initialization, manipulation and readout schemes in multi-quantum dot
architectures.
