Charge Offset Stability in Si Single Electron Devices with Al Gates

TL;DR

This study investigates charge offset drift in silicon single electron devices with aluminum gates, revealing that defect-related instabilities in AlOx are a key factor influencing device stability.

Contribution

It provides the first detailed comparison of charge offset drift in Si SEDs with Al gates, highlighting defect-induced instability as a primary concern.

Findings

Charge offset drift is 0.15 e in Al-gated Si SEDs.

Drift magnitude is intermediate compared to Al/AlOx/Al junctions and Si-gated SEDs.

Defects in AlOx are identified as main cause of drift instability.

Abstract

We report on the charge offset drift (time stability) in Si single electron devices (SEDs) defined with aluminum (Al) gates. The size of the charge offset drift (0.15 $e$) is intermediate between that of Al/AlO$_x$/Al tunnel junctions (greater than 1 $e$) and Si SEDs defined with Si gates (0.01 $e$). This range of values suggests that defects in the AlO$_x$ are the main cause of the charge offset drift instability.