Effect of in situ hydrogen plasma on the ferroelectricity of hafnium zirconium oxide films

Abstract

The emerging field of ferroelectric hafnium zirconium oxide has garnered increased attention recently for its wide array of applications from nonvolatile memory and transistor devices to nanoelectromechanical transducers. Atomic layer deposition is one of the preferred techniques for the fabrication of hafnium zirconium oxide thin films, with a standard choice of oxidizer being either O3 or H2O. In this study, we explore various oxidizing conditions and report on the in situ treatment of hydrogen plasma after every atomic layer during the deposition of hafnium zirconium oxide to increase the virgin state polarization. Three different oxidization methods were utilized during the fabrication of the Hf0.5Zr0.5O2 films: H2O, O2 plasma, and O2 plasma followed by H2 plasma. The 10 and 8 nm thick films oxidized with only O2 plasma result in initially anti-ferroelectric films. Comparatively, the addition of H2 plasma after every O2 plasma step results in films with strong ferroelectric behavior. Peak shifting of the GIXRD pattern suggests that the sequential O2-H2 plasma films tend more to the orthorhombic phase as compared to the O2 plasma and H2O oxidized films.

Extraction of Preisach model parameters for fluorite-structure ferroelectrics and antiferroelectrics

“…The extracted , , , , , , , , , and are 6.40 μC/cm 2 , 6.34 μC/cm 2 , 1.12 MV/cm, 2.39 MV/cm, − 6.61 μC/cm 2 , − 6.51 μC/cm 2 , − 1.22 MV/cm, − 2.35 MV/cm, 0.43 μC/cm 2 , 33.70, respectively.

Figure 6 Ferroelectric parameters extracted from the literature for Al-doped 6 , 7 , Gd-doped 8 , La-doped 9 , Si-doped 1 , 10 – 12 , Sr-doped 13 , Y-doped 14 , 15 , Zr-doped 4 , 10 , 16 – 26 , and undoped 4 , 5 HfO 2 thin films, where is defined as the average of and . ( a ) Saturated polarization vs. coercive field .

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“… Ferroelectric parameters extracted from the literature for Al-doped 6 , 7 , Gd-doped 8 , La-doped 9 , Si-doped 1 , 10 – 12 , Sr-doped 13 , Y-doped 14 , 15 , Zr-doped 4 , 10 , 16 – 26 , and undoped 4 , 5 HfO 2 thin films, where is defined as the average of and . ( a ) Saturated polarization vs. coercive field .…”

“…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 – 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 – 12 , Sr-doped 13 , Y-doped 14 , 15 , Zr-doped 4 , 10 , 16 – 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 ( - ).…”

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 ).…”