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

Abstract

In the past few years, spin qubits in Si quantum dots (QDs) have demonstrated great potential to fulfill the Loss DiVincenzo quantum computing criteria [1]. Although good controllability of single electron spins has been demonstrated for QDs defined on the two-dimensional electron gas (2DEG) formed at the GaAs/AlGaAs heterojunction by using top-down lithography [2], the coherence of electron spins deteriorates rapidly in GaAs due to rich nuclear spins in GaAs. Electron spins confined in silicon based QDs are expected to have longer coherence time thanks to the low nuclear spin density of silicon based materials, with coherence times as long as 6 seconds recently been demonstrated [3]. This has further asserted the advantage of using Si as a platform to realize spin qubits and several Si QD structures have been investigated in silicon on insulator (SOI) [4], [5] and Si (2DEG) [6]. In previous work, we have presented the design and simulation of a novel SOI-based spin qubit platform using Al FinFET gates and Si side gates. The simulations demonstrated the ability of this platform to transfer, confine and detect single electrons [7], [8]. In this letter, we report a novel fabrication process to realize high density silicon based QDs with close proximity Al and Si gates on ultrathin SOI for spin qubit applications