Electric field induced charge noise in doped silicon: ionization of phosphorus donors

TL;DR

This study investigates how electric fields induce charge noise in doped silicon, revealing that tunneling from phosphorus donors causes 1/f noise, with implications for quantum device stability.

Contribution

It demonstrates the dependence of charge noise on doping density and electric field, highlighting electric field induced tunneling as a noise source in silicon-based devices.

Findings

Charge noise increases with doping density.

Charge noise exhibits a 1/f spectral dependence.

Electric field induces tunneling from phosphorus donors.

Abstract

We report low frequency charge noise measurement on silicon substrates with different phosphorus doping densities. The measurements are performed with aluminum single electron transistors (SETs) at millikelvin temperatures where the substrates are in the insulating regime. By measuring the SET Coulomb oscillations, we find a gate voltage dependent charge noise on the more heavily doped substrate. This charge noise, which is seen to have a 1/f spectrum, is attributed to the electric field induced tunneling of electrons from their phosphorus donor potentials.