Silencing noisy 2DEG wafers

TL;DR

This paper demonstrates that inserting a thin insulator layer between gates and GaAs/AlGaAs heterostructures can significantly reduce telegraphic noise in sensitive electrostatic devices, with charge trapping affecting device stability.

Contribution

Introducing a thin insulator layer to suppress telegraph noise in GaAs/AlGaAs devices and exploring charge trapping effects for stabilization.

Findings

Insulator layer reduces telegraph noise in devices.

Charge trapping causes slow drift in device behavior.

Charge manipulation offers stabilization strategies.

Abstract

Telegraphic noise is one of the most significant problems that arises when making sensitive measurements with lateral electrostatic devices. In this paper we demonstrate that a wafer which had only produced devices with significant telegraph noise problems can be made to produce 'quiet' devices if a thin insulator layer is placed between the gates and the GaAs/AlGaAs heterostructure. A slow drift in the resulting devices is attributed to the trapping of charges within the specific insulator used. This charge can be manipulated, leading to strategies for stabilizing the device.