Direct comparison of ferroelectric properties in Hf_0.5Zr_0.5O₂ between thermal and plasma-enhanced atomic layer deposition

Abstract

Since the discovery of ferroelectricity in doped/alloyed HfO2 and ZrO2 thin film, many device engineers have been attracted to its sustainable ferroelectricity at the thickness of a few nanometer. While most of the previous studies have mainly focused on the ferroelectric properties of the thermally atomic layer deposited (THALD) Hf0.5Zr0.5O2 (HZO), the plasma-enhanced ALD (PEALD) HZO has not received much attention. In this work, a direct comparison between the two types of HZO thin films is carried out, where we found that a tradeoff exists between these two fabrication methods. While the THALD HZO was able to maintain a higher cycling endurance, the PEALD HZO showed more stable characteristics over the cycling with reduced wake-up and fatigue effects, in addition to better tolerance against breakdown under high electric field. Furthermore, the PEALD HZO could be crystallized with post deposition annealing at 350 °C, which is of great interest for the back-end-of-line compatibility with silicon fabrication processes.

Investigation of Time Dependent Dielectric Breakdown (TDDB) of Hf0.5Zr0.5O2-Based Ferroelectrics Under Both Forward and Reverse Stress Conditions

“…It is reported that the use of H2O2 or O plasma at the initial stage of film growth to suppress oxygen vacancy accumulation at the bottom electrode [21]. In addition, the film grown with plasmaenhanced ALD (PEALD) has also been reported for the oxygen vacancy reduction, leading to higher breakdown voltage and thus better TDDB performance [22].…”

Extraction of Preisach Model Parameters for Fluorite-Structure Ferroelectrics and Antiferroelectrics

“…The proposed modeling framework was used to extract ferroelectric parameters for Al-doped 6,7 , Gd-doped 8 , La-doped 9 , Si-doped 1,[10][11][12] , Sr-doped 13 , Y-doped 14,15 , Zr-doped 4,10,[16][17][18][19][20][21][22][23][24][25][26] , and undoped 4,5 HfO 2 thin films reported in the literature as shown in Fig. 6.…”

“…Ferroelectric field-effect transistors (FeFETs), as emerging memory, find a niche in such applications due to their ultra-fast program/erase time, low operation voltage, and low power consumption [1][2][3] . Despite the fact that hafnium oxide 4,5 and its doped variants (Al-doped 6,7 , Gd-doped 8 , La-doped 9 , Si-doped 1,[10][11][12] , Sr-doped 13 , Y-doped 14,15 , Zr-doped 4,10,[16][17][18][19][20][21][22][23][24][25][26] ) have been extensively studied and characterized over the past few years, little has been done to aggregate those data into ferroelectric properties to provide the insight necessary to create a predictive model for ferroelectrics. Such a predictive model cannot be realized without the accurate determination of a multitude of ferroelectric parameters from various experimental hysteresis loops (Q FE -E FE ).…”

Variability Study of Ferroelectric Field-Effect Transistors Towards 7nm Technology Node

“…We extracted those ferroelectric parameters from the experiments of our group's previous research [10]. The plasma enhanced ALD was used for depositing the Hf0.5Zr0.5O2 layer in [13]. Fig.…”