Characterization of Silicon MOS quantum dots fabricated in a full 300mm CMOS process for spin qubit applications

Silicon spin qubits have been considered as one of the most promising candidates for large scale quantum computers, due to their long coherence time, potential to operate at relatively high temperatures and compatibility with CMOS technology for upscaling [1-2]. However, experimental demonstrations have been limited to a few qubits [3-4], and further upscaling requires better process control and a thorough characterization of material properties.

We address this challenge by fabricating quantum dot arrays in a state-of-the-art 300mm fully CMOS compatible fabrication process, employing both e-beam and optical lithography [5]. We present the fabrication and electrical characterization of well-controlled quantum dots formed in a Si-MOS substrate. Additionally, we discuss the effect of process induced defects and device uniformity, both crucial for large qubit arrays. These results provide important feedback necessary for future upscaling of spin qubits.

[1] Li et al., Science Adv., 4(7) (2018)

[2] Vandersypen et al., npj Quantum Information 3.1 (2017)

[3] Yoneda et al., Nature Nanotech. 13 (2018)

[4] Chan et al., Nano Letters 21.3 (2021)

[5] Li et al., Proc. of IEDM (2020)