Reduced plasma oxidation in metal single electron transistors for increased bandwidth

Plasma oxidation parameters used to form the tunnel barriers in aluminum based single electron transistors (SETs) are varied to reduce the resistance-area (RA) product, thereby increasing the conductance and bandwidth for use as quantum dot charge sensors. Aluminum based SETs with high bandwidth could be integrated into the MOS gate layer for spin qubit readout and reduce pressure on in-plane densities. Our group’s previous work applied plasma oxidation to yield SETs sufficiently stable over weeks, allowing the metal-based SET to be considered for qubit readout. By varying the plasma oxidation duration, the resistance of the tunnel junction can be tuned, which both increases electrical conductance and bandwidth. Coulomb blockade measurements taken on these plasma oxidized SETs will be presented and analyzed for their potential as charge sensors in this context.