Current-Mode Deep Level Transient Spectroscopy of a Semiconductor Nanowire Field-Effect Transistor

TL;DR

This paper introduces a novel current-mode deep level transient spectroscopy (I-DLTS) technique tailored for semiconductor nanowires, enabling the analysis of deep trap states and surface barrier heights despite their small capacitance.

Contribution

The paper presents a new I-DLTS method for nanowires, overcoming limitations of traditional DLTS and allowing detailed trap characterization and surface barrier measurement.

Findings

Successfully determined activation energies of deep defect states in ZnO nanowires.

Measured surface barrier heights in semiconductor nanowires.

Demonstrated applicability of I-DLTS for nanowire defect analysis.

Abstract

One of the main limiting factors in the carrier mobility in semiconductor nanowires is the presence of deep trap levels. While deep-level transient spectroscopy (DLTS) has proved to be a powerful tool in analysing traps in bulk semiconductors, this technique is ineffective for the characterisation of nanowires due to their very small capacitance. Here we introduce a new technique for measuring the spectrum of deep traps in nanowires. In current-mode DLTS (I-DLTS) the temperature-dependence of the transient current through a nanowire field-effect transistor in response to an applied gate voltage pulse is measured. We demonstrate the applicability of I-DLTS to determine the activation energy and capture cross-sections of several deep defect states in zinc oxide nanowires. In addition to characterising deep defect states, we show that I-DLTS can be used to measure the surface barrier height in semiconductor nanowires.