Measuring the Capacitance of Individual Semiconductor Nanowires for Carrier Mobility Assessment

TL;DR

This paper directly measures the capacitance of individual germanium nanowire transistors to accurately assess carrier mobility, revealing that surround-gated structures offer superior electrostatic control for nanoelectronics.

Contribution

It introduces a direct measurement method for nanowire capacitance, improving mobility assessment accuracy and comparing gate structures for optimal device performance.

Findings

Surround-gated nanowire transistors have higher capacitance.

Surround-gated devices exhibit better electrostatic control.

This method removes uncertainties in mobility calculations.

Abstract

Capacitance-voltage characteristics of individual germanium nanowire field effect transistors were directly measured and used to assess carrier mobility in nanowires for the first time; thereby removing uncertainties in calculated mobility due to device geometries, surface and interface states and gate dielectric constants and thicknesses. Direct experimental evidence showed that surround-gated nanowire transistors exhibit higher capacitance and better electrostatic gate control than top-gated devices, and are the most promising structure for future high performance nanoelectronics.