New tools for the direct characterisation of FinFETs

TL;DR

This paper introduces a method using classical transport theories and simple measurements to characterize FinFETs, enabling extraction of key parameters and interface trap densities directly on advanced devices.

Contribution

It presents a novel approach combining thermionic emission theory with measurements and simulations to analyze transport mechanisms and interface traps in FinFETs.

Findings

Parameters like transport region and barrier height can be extracted from measurements.

Interface trap density can be determined using combined experimental and simulated data.

The method applies to various transport regimes in ultra-scaled FinFETs.

Abstract

This paper discusses how classical transport theories such as the thermionic emission, can be used as a powerful tool for the study and the understanding of the most complex mechanisms of transport in Fin Field Effect Transistors (FinFETs). By means of simple current and differential conductance measurements, taken at different temperatures and different gate voltages ($V_G$'s), it is possible to extrapolate the evolution of important parameters such as the spatial region of transport and the height of thermionic barrier at the centre of the channel. Furthermore, if the measurements are used in conjunction with simulated data, it becomes possible to also extract the interface trap density of these objects. These are important results, also because these parameters are extracted directly on state-of-the-art devices and not in specially-designed test structures. The possible characterisation of the different regimes of transport that can arise in these ultra-scaled devices having a doped or an undoped channel are also discussed. Examples of these regimes are, full body inversion and weak body inversion. Specific cases demonstrating the strength of the thermionic tool are discussed in sections \ref{sec:II}, \ref{sec:III} and \ref{sec:IV}. This text has been designed as a comprehensive overview of 4 related publications (see Ref. [2-5]) and has been submitted as a book chapter in Ref. [6]).