[paper] CMOS floating-gate device for quantum control hardware

Michele Castriotta¹, Enrico Prati², Giorgio Ferrari¹

Cryogenic characterization and modeling of a CMOS floating-gate device 

for quantum control hardware

preprint arXiv:2110.02315, 2021

1 Dipartimento di Elettronica, Informazione e Bioingegneria, Politecnico di Milano (I)
2 Istituto di Fotonica e Nanotecnologie, Consiglio Nazionale delle Ricerche (I)

Abstract - We perform the characterization and modeling of a floating gate device realized with a commercial 350-nm CMOS technology at cryogenic temperature. The programmability of the device offers a solution in the realization of a precise and flexible cryogenic system for qubits control in large-scale quantum computers. The device stores onto a floating-gate node a non-volatile charge, which can be bidirectionally modified by Fowler-Nordheim tunneling and impact-ionized hot electron injection. These two injection mechanisms are characterized and modeled in compact equations both at 300 K and 15 K. At cryogenic temperature, we show a fine-tuning of the stored charge compatible with the operation of a precise analog memory. Moreover, we developed accurate simulation models of the proposed floating-gate device that set the stage for designing a programmable analog circuit with better performances and accuracy at a few Kelvin. This work offers a solution in the design of configurable analog electronics to be employed for accurately read out the qubit state at deep-cryogenic temperature.

Fig: Simplified layout of the p-type floating-gate device under test. The capacitive coupling to the floating-gate node  is realized with the poly 2 control gate.

Acknowledgments: This work was supported by QUASIX Grant from  Italian Space Agency. This work was partially performed at Polifab, the  micro- and nanofabrication facility of Politecnico di Milano