Enhancement of Ferroelectricity in 5 nm Metal-Ferroelectric-Insulator Technologies by Using a Strained TiN Electrode.

Cheng-Hung Wu,Kuan-Chi Wang,Chenming Hu,Yu-Yun Wang,Chun-Jung Su,Tian-Li Wu

doi:10.3390/nano12030468

Abstract

In this work, the ferroelectric characteristic of a 5 nm Hf0.5Zr0.5O2 (HZO) metal-ferroelectric-insulator-semiconductor (MFIS) device is enhanced through strained complementary metal oxide semiconductor (CMOS)-compatible TiN electrode engineering. Strained TiN top-layer electrodes with different nitrogen (N) concentrations are deposited by adjusting the sputtering process conditions. The TiN electrode with 18% N exhibits a compressive characteristic, which induces tensile stress in a 5 nm HZO film. A device with 18% N in TiN shows a higher remanent polarization (2Pr) and larger capacitance value than the compared sample, indicating that the strained TiN is promising for enhancing the ferroelectricity of sub-5 nm HZO devices.

Highlights

Technologies by Using a Strained TiNHfO2 -based dielectrics are promising ferroelectric materials for nonvolatile memory, negative-capacitance FETs, and neuromorphic applications because of their compatibility with complementary metal-oxide-semiconductor (CMOS) technology [1,2]
To further enhance the performance in ferroelectric FETs (FeFETs) and negative-capacitance FETs (NCFETs), it is important to enhance the ferroelectricity in metal-ferroelectric-insulator-semiconductor (MFIS) devices, which is the major foundation for high-performance FeFETs and NCFETs
Is relatively thin compared with the bottom electrode and top electrode, the reporting literature only consider the coefficient of thermal expansion (CTE) between the bottom electrode and top electrode [6]

Summary

Introduction

HfO2 -based dielectrics are promising ferroelectric materials for nonvolatile memory, negative-capacitance FETs, and neuromorphic applications because of their compatibility with complementary metal-oxide-semiconductor (CMOS) technology [1,2]. Studies have reported that the strain exerted through the different electrodes and substrates [4,5,6,7] can be used as an alternative method of inducing the ferroelectric characteristic because the tensile stress along the in-plane direction can enhance transformation from the tetragonal phase to the orthorhombic phase. To further enhance the performance in ferroelectric FETs (FeFETs) and negative-capacitance FETs (NCFETs), it is important to enhance the ferroelectricity in metal-ferroelectric-insulator-semiconductor (MFIS) devices, which is the major foundation for high-performance FeFETs and NCFETs. in this study, we report, to the best of our knowledge for the first time, using strained TiN as a top electrode in 5 nm

Methods

Results

Conclusion