Towards Si finFET quantum devices with reproducible behavior

Hole spin qubits in Si finFETs show great promise for a quantum computing platform exhibiting fast and all electrical qubit control, even when operated at temperatures above 1K. While charge noise affects all platforms, disorder is one of the main limitations in current Si-MOS qubit technology.

Here, we present our work towards reducing disorder and trapped charges by investigating material stacks utilizing Hall bar and percolation density measurements. Additionally, fabricating quantum dot devices with ultra-small gate length and pitch will enable a path towards mitigating disorder. We show Si finFET quantum dot devices exhibiting sub 20 nm gate lengths with a small pitch, fabricated with high-resolution e-beam lithography. The reproducibility of quantum dot formation is assessed through transport measurements, RF gate reflectometry, and charge sensing. From these results we draw conclusions on gate stack and fin shape optimization.