Random Telegraph Noise of a 28-nm Cryogenic MOSFET in the Coulomb Blockade Regime

TL;DR

This study investigates two-level random telegraph noise in a 28-nm cryogenic PMOSFET at 14 K, revealing quantum dot effects and defect trap influences, with implications for cryogenic CMOS circuit design.

Contribution

It provides the first detailed observation of RTN linked to quantum confinement in commercial short-channel PMOS devices at cryogenic temperatures.

Findings

RTN amplitude varies with gate voltage in the Coulomb blockade region.

Quantum dot signatures are evident in both current and noise measurements.

RTN characteristics are more prominent in smaller technology nodes.

Abstract

We observe rich phenomena of two-level random telegraph noise (RTN) from a commercial bulk 28-nm p-MOSFET (PMOS) near threshold at 14 K, where a Coulomb blockade (CB) hump arises from a quantum dot (QD) formed in the channel. Minimum RTN is observed at the CB hump where the high-current RTN level dramatically switches to the low-current level. The gate-voltage dependence of the RTN amplitude and power spectral density match well with the transconductance from the DC transfer curve in the CB hump region. Our work unequivocally captures these QD transport signatures in both current and noise, revealing quantum confinement effects in commercial short-channel PMOS even at 14 K, over 100 times higher than the typical dilution refrigerator temperatures of QD experiments (<100 mK). We envision that our reported RTN characteristics rooted from the QD and a defect trap would be more prominent for smaller technology nodes, where the quantum effect should be carefully examined in cryogenic CMOS circuit designs.