Realization of Al tri-gate single electron turnstile co-integrated with a close proximity electrometer SET

This paper presents a novel fabrication process to realize high density silicon based quantum dot devices with close proximity Al and Si gates on ultrathin silicon-on-insulator for spin qubit applications. Al gates surrounding a Si nanowire channel can adjust tunnelling barrier height electrically, while Si plunger side gates enable precise control of the quantum dots potential. This device is fabricated using a multi-layer electron beam lithography process that is fully compatible with metal oxide semiconductor technology. Low temperature electrical measurements and Coulomb oscillation characteristics have demonstrated the capability of this structure to electrostatically define two coupled single electron transistors, one to be used as a turnstile device and the other as an electrometer.

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► We realized a novel SOI-based quantum dots platform using Al tri-gate structure.
► Close proximity Si plunger gates provide precise control of the quantum dots.
► This platform offers great potential for electron spin qubit applications.
► The multi-layer e-beam process employed here has alignment accuracy close to 15 nm.
► We demonstrated coulomb oscillations evidence of single quantum dot formation.