Impact of Radiation Effect on Ferroelectric Al-Doped HfO2 Metal-Ferroelectric- Insulator-Semiconductor Structure

Wanli Zhang,Teng Wang,Lian Cui,Guangzhao Wang,Xiaojiang Long,Zhuojun Chen,Minghua Tang,Shaoan Yan,Pengyu Su,Yongguang Xiao

doi:10.1109/access.2020.3000865

Abstract

The $\gamma $ -ray total dose radiation effects on ferroelectric Al-doped HfO2 (HfAlO) thin films with an n-type Si substrate were studied. The $I$ - $V$ , $P$ - $V$ , $C$ - $V$ and fatigue characteristics of the HfAlO-based Metal-Ferroelectric-Insulator-Semiconductor (MFIS) structure were analyzed with the increasing total dose from 0 to 1 Mrad (Si). The remnant polarization ( $P_{\mathrm {r}}$ ) values, the capacitance ( $C$ ) values and the switching voltage ( $V_{\mathrm {c}}$ ) of this MFIS gate structure decreased with the increasing total dose. A TCAD model of Metal/HfAlO/SiO2/Si (MFIS) was proposed to explain the degradation mechanism of ferroelectric properties of the MFIS structure. We find that the new interface defects caused by radiation can reduce the electric field strength with the increasing total dose, which can significantly influence the irradiation properties of the HfAlO/SiO2/n-Si gate structure. These results provide the basis to applications for the HfO2-based devices in radiation working environment.

Highlights

Nowadays the most commercial of nonvolatile memory (NVM) available are semiconductor Flash-based memory
The doped HfO2 thin films with a thickness below 10 nm have the advantages of high scalability, excellent retention, mature production and good CMOS compatibility, which are considered to be the best replacement for the traditional ferroelectric materials of field-effect transistor (FeFET) in information storage fields [4]–[6]
As the total dose of the γ -ray radiation increases, more movable charges or charged domain walls can be compensated by radiation oxide trapped defects or interface defects, while these movable charges or charged domain walls can take part in the polarization switching for ferroelectric thin films as reported by PlaceresJiménez et al [23]

Summary

Introduction

Nowadays the most commercial of nonvolatile memory (NVM) available are semiconductor Flash-based memory. To further study the radiation effects on ferroelectric properties of the HfAlO MFIS structure, the P+r , P−r , Vc+ and Vc− of 4 groups (20 devices for each group) were tested before and after γ -ray radiation.

Results

Conclusion