Excellent charge offset stability in a Si-based single-electron tunneling transistor

We have measured the long-term drift and the short-term $\text{1/f}$ noise in the charge offset $Q_0\mathrm{(t)}$ in two Si-based single-electron tunneling transistors (SETTs). In contrast to metal-based SETTs, these devices show excellent charge stability, drifting by less than $\text{0.01e}$ over weeks. The short-term $\text{1/f}$ noise magnitude is similar to the metal-based devices, demonstrating that different mechanisms are responsible for the short-term noise versus the long-term drift. Finally, we show that, in addition to the excellent stability over time, it may be possible to make the devices more robust with respect to voltage-induced instability as well.