Low-frequency noise assessment of ferro-electric field-effect transistors with Si-doped HfO2 gate dielectric

E Simoen,N Ronchi,J Van Houdt,G Van Den Bosch,D Linten,B J O’Sullivan

doi:10.1063/5.0029833

Abstract

The low-frequency noise of planar transistors with ferroelectric Si-doped HfO2 as a gate dielectric is investigated and compared with that of undoped HfO2 reference devices. Predominantly 1/f-like spectra have been observed, which are governed by carrier number fluctuations or trapping in the gate stack. The corresponding noise power spectral density is about a factor of three higher for the reference devices, indicating that Si-doping reduces in a way similar to the trap density in the HfO2 layer.

Highlights

One of the powerful methods to investigate charge traps in high-κ dielectrics is low-frequency (LF) noise spectroscopy.16 The type of oxide trap information that can be derived will largely depend on the type of noise present in the material: flicker or 1/f noise enables the study of so-called border traps in the gate dielectric, at tunneling distance (1 nm–2 nm) from the Si/SiO2 interface,17–19 while Generation–Recombination (GR) noise probes either individual defect centers in the gate stack giving rise to Random
LF noise data are presented for planar Field-Effect Transistors (FEFETs) with 9.5 nm Si-doped HfO2/TiN14 and benchmarked to undoped HfO2/TiN stacks subjected to a similar thermal budget, which display ferroelectric and paraelectric behaviors, respectively
The highκ dielectric has been deposited by Atomic Layer Deposition (ALD) atop of a 1.2 nm in situ steam generated (ISSG) SiO2 interfacial oxide layer

Summary

Introduction

One of the powerful methods to investigate charge traps in high-κ dielectrics is low-frequency (LF) noise spectroscopy.16 The type of oxide trap information that can be derived will largely depend on the type of noise present in the material: flicker or 1/f noise enables the study of so-called border traps in the gate dielectric, at tunneling distance (1 nm–2 nm) from the Si/SiO2 interface,17–19 while Generation–Recombination (GR) noise probes either individual defect centers in the gate stack giving rise to Random.

Results

Conclusion