The growth and characterisation of back-gated high mobility two-dimensional electron gas structures

Abstract

This paper presents a description and analysis of two back-gated high mobility GaAs/AlGaAs two-dimensional electron gas (2DEG) structures. The results show the carrier density in the 2DEG varying over a wide range with a low leakage current from the 2DEG to the n + substrate, which acts as the back-gate. With the carrier density enhanced, a second 2DEG formed in a different part of the structure from the first one. These samples will be used for the study of low-dimensional structures by using a patterned front gate on the surface of the epilayer to define the shape of the structure and the back-gate to vary the carrier density.