scholarly journals Structural and electrical properties of ferroelectric BiFeO3/HfO2 gate stack for nonvolatile memory applications

2018 ◽  
Vol 08 (05) ◽  
pp. 1850037
Author(s):  
Nitish Yadav ◽  
Kamal Prakash Pandey ◽  
Pramod Narayan Tripathi
Keyword(s):  
Nonvolatile Memory ◽  
Annealing Temperature ◽  
Perovskite Phase ◽  
Rf Magnetron Sputtering ◽  
Xrd Analysis ◽  
Gate Stack ◽  
Retention Capacity ◽  
Structural And Electrical Properties ◽  
Memory Applications ◽  
Mfis Structure

Difficulties in the fabrication of direct interface of ferroelectric BiFeO3 on the gate of ferroelectric field effect transistor (FeFET) is well known. This paper reports the optimization and fabrication of ferroelectric/dielectric (BiFeO3/HfO[Formula: see text] gate stack for the FeFET applications. RF magnetron sputtering has been used for the deposition of BiFeO3, HfO2 films and their stack. X-Ray diffraction (XRD) analysis of BiFeO3 shows the dominant perovskite phase of (104), (110) orientation at 2[Formula: see text] at the annealing temperature of 500[Formula: see text]C. XRD analysis also confirms the amorphous nature of the HfO2 film at annealing temperature of 400[Formula: see text]C, 500[Formula: see text]C and 600[Formula: see text]C. Multiple angle analysis shows the variation ion the refractive index between 2.98–3.0214 for BiFeO3 and 2.74–2.9 for the HfO2 film with the annealing temperature. Metal/Ferroelectric/Silicon (MFS), Metal/Ferroelectric/Metal (MFM), Metal/Insulator/Silicon (MIS), and Metal/Ferroelectric/Insulator/Silicon (MFIS) structures have been fabricated to obtain the electric characteristic of the ferroelectric, dielectric and their stacks. Electrical characteristics of the MFIS structure show the memory improvement from 2.7[Formula: see text]V for MFS structure to 4.65[Formula: see text]V for MFIS structure with 8[Formula: see text]nm of buffer dielectric layer. This structure also shows the breakdown voltage of 40[Formula: see text]V with data retention capacity greater than [Formula: see text] iteration cycles.

GROWTH OF SPUTTERED-ALUMINUM OXIDE THIN FILMS ON Si (100) AND Si (111) SUBSTRATES WITH Al2O3 BUFFER LAYER

2016 ◽  
Vol 23 (03) ◽  
pp. 1650016
Author(s):  
WEI QIANG LIM ◽  
SUBRAMANI SHANMUGAN ◽  
MUTHARASU DEVARAJAN
Keyword(s):  
Thin Films ◽  
Aluminum Oxide ◽  
Buffer Layer ◽  
Annealing Temperature ◽  
Rf Magnetron Sputtering ◽  
Xrd Analysis ◽  
X Ray Diffraction ◽  
Si Substrates ◽  
Atomic Force ◽  
Section Analysis

Aluminum oxide (Al2O3) thin films with Al2O3 buffer layer were deposited on Si (100) and Si (111) substrates using RF magnetron sputtering of Al2O3 target in Ar atmosphere. The synthesized films were then annealed at the temperature of 400[Formula: see text]C, 600[Formula: see text]C and 800[Formula: see text]C in nitrogen (N2) environment for 6[Formula: see text]h. Structural properties and surface morphology are examined by using X-Ray Diffraction (XRD), Field Emission Scanning Electron Microscope (FESEM) and Atomic Force Microscope (AFM). XRD analysis indicated that different orientation of Al2O3 were formed with different intensities due to increase in the annealing temperature. From FESEM cross-section analysis results, it is observed that the thickness of films were increased as the annealing temperature increased. EDX analysis shows that the concentration of aluminum and oxygen on both the Si substrates increased with the increase in annealing temperature. The surface roughness of the films were found to be decreased first when the annealing temperature is increased to 400[Formula: see text]C, yet the roughness increased when the annealing temperature is further increased to 800[Formula: see text]C.

THERMALLY-DRIVEN STRUCTURAL CHANGES OF SPUTTERED COPPER ALUMINUM OXIDE FILMS (Cu–Al2O3) GROWN BY LAYER STACKING METHOD

2017 ◽  
Vol 24 (Supp01) ◽  
pp. 1850002
Author(s):  
WEI QIANG LIM ◽  
SHANMUGAN SUBRAMANI ◽  
MUTHARASU DEVARAJAN
Keyword(s):  
Crystallite Size ◽  
Structural Properties ◽  
Structural Changes ◽  
Annealing Temperature ◽  
Compressive Strain ◽  
Rf Magnetron Sputtering ◽  
Xrd Analysis ◽  
X Ray ◽  
Layer Stacking ◽  
Deposited Films

Copper aluminium oxide (Cu–Al2O3) films were synthesized on Si(111) substrates through RF magnetron sputtering by using the layer stacking technique. Cu and Al2O3 targets were used to deposit Cu and Al2O3 thin films under Ar atmosphere, respectively and the deposited films were then annealed under N2 environment at 350[Formula: see text]C, 450[Formula: see text]C and 550[Formula: see text]C for 6[Formula: see text]h. The structural properties of the films were investigated by using X-ray diffraction (XRD) while the surface morphology and topography of the deposited films were examined through Field Emission Scanning Electron Microscopy (FESEM), Energy Dispersive X-ray (EDX) and Atomic Force Microscopy (AFM). XRD analysis revealed the existence of multiple phases of CuO, Al2O3 and CuAl2O4 in the deposited films on Si(111) substrates. As a result of the annealing effect, the peak intensities of CuO, Al2O3 and CuAl2O4 were found to be increased along with the shifting of peak positions. Williamson–Hall (WH) analysis was also implemented to analyze the structural properties such as crystallite size, stress, strain, and energy density. Based on the three models used in WH analysis, the changes in the crystallite size and strain of the films were indicated to be anomalous with the changes in the annealing temperature. Moreover, the strain of films was also showed to be changed from compressive strain into tensile strain. The FESEM results also indicated the formation of various surface morphologies under various annealing temperatures whereas EDX analysis showed an increased atomic percentage of Cu, Al, and O due to the effect of increase in annealing temperature. The AFM analysis showed that the surface roughness of the deposited films increased with the increase in the annealing temperature.

Structural and electrical properties of excess PbO doped Pb(Zr0.52Ti0.48)O3 thin films using rf magnetron sputtering method

1998 ◽  
Vol 13 (12) ◽  
pp. 3436-3441 ◽  
Author(s):  
Tae Song Kim ◽  
Dong Joo Kim ◽  
Jeon Kook Leea ◽  
Hyung Jin Jung
Keyword(s):  
Thin Films ◽  
Dielectric Constant ◽  
Electrical Properties ◽  
Lead Zirconate Titanate ◽  
Perovskite Phase ◽  
Rf Magnetron Sputtering ◽  
Xrd Analysis ◽  
Lead Zirconate ◽  
Hysteresis Curve ◽  
Grown Film

Well-crystallized Pb(Zr0.52Ti0.48)O3 thin films (4000 Å thickness) can be synthesized on Pt/Ti/SiO2/Si(100) substrate at a temperature as low as 520 °C. The polycrystalline lead zirconate titanate (PZT) perovskite phase formation was confirmed with x-ray diffraction (XRD) analysis, and growth morphologies were studied with a scanning electron microscope (SEM). The electrical properties of PZT thin films were characterized through P-E hysteresis curve, dielectric constant, and loss, fatigue, and leakage current measurements. Remanent polarization (Pr) and coercive field (Ec) of as-grown film were 8–30 μC/cm2 and 24–64 kV/cm with the variation of applied voltage (5–15 V). The post-annealing enhances the electrical properties even at 500 °C, which is below the as-grown temperatures (520 °C). The average polarization loss after applying rectangular pulse (Vp-p = 10 V) up to 1011 cycles was 40.9% for a 300 μm small dot and 22% for a 500 μm large dot, which are relatively improved values for platinum electrode. The values of dielectric constant (ε′) and tan δ measured with small signal sign wave (1 V, 10 kHz) were 1207 and 0.066 in the case of as-grown film.

scholarly journals Properties of RF Magnetron-Sputtered Copper Gallium Oxide (CuGa2O4) Thin Films

Coatings ◽  
2021 ◽  
Vol 11 (8) ◽  
pp. 921
Author(s):  
Ashwin Kumar Saikumar ◽  
Sreeram Sundaresh ◽  
Shraddha Dhanraj Nehate ◽  
Kalpathy B. Sundaram
Keyword(s):  
Thin Films ◽  
Annealing Temperature ◽  
Wavelength Region ◽  
Rf Magnetron Sputtering ◽  
Xrd Analysis ◽  
X Ray Diffraction ◽  
Morphological Studies ◽  
Increasing Trend ◽  
First Time ◽  
Post Deposition

Thin films of CuGa2O4 were deposited using an RF magnetron-sputtering technique for the first time. The sputtered CuGa2O4 thin films were post-deposition annealed at temperatures varying from 100 to 900 °C in a constant O2 ambience for 1.5 h. Structural and morphological studies were performed on the films using X-ray diffraction analysis (XRD) and a Field Emission Scanning Electron Microscope (FESEM). The presence of CuGa2O4 phases along with the CuO phases was confirmed from the XRD analysis. The minimum critical temperature required to promote the crystal growth in the films was identified to be 500 °C using XRD analysis. The FESEM images showed an increase in the grain size with an increase in the annealing temperature. The resistivity values of the films were calculated to range between 6.47 × 103 and 2.5 × 108 Ωcm. Optical studies were performed on all of the films using a UV-Vis spectrophotometer. The optical transmission in the 200–800 nm wavelength region was noted to decrease with an increase in the annealing temperature. The optical bandgap value was recorded to range between 3.59 and 4.5 eV and showed an increasing trend with an increase in the annealing temperature.

A Study of the Structural and Electrical Characteristics of Thermally Oxidized Al-Doped Zn3N2 Film on Glass

2012 ◽  
Vol 545 ◽  
pp. 294-299
Author(s):  
L.Y. Low ◽  
Mat Johar Abdullah ◽  
N.H. Al-Hardan
Keyword(s):  
Zinc Oxide ◽  
Electrical Properties ◽  
Annealing Temperature ◽  
Rf Sputtering ◽  
Xrd Analysis ◽  
Nitride Film ◽  
Electrical Characteristics ◽  
Glass Substrates ◽  
Zinc Nitride ◽  
Structural And Electrical Properties

We report the deposition of aluminium doped zinc nitride film (Al-Zn3N2) on glass substrates by RF sputtering. Thermal oxidation of the film under different annealing temperature (500°C to 600°C) was carried out. Structural and electrical properties of the annealed films were investigated. XRD analysis showed that Al-Zn3N2film was successfully converted into Al-N zinc oxide (ANZO) at 500°C. I-V characteristics of the films were measured and the lowest estimated resistivity of the films of 4kΩ.cm can be achieved at 600°C.

Annealing Treatment of Ferroelectric Pb (Zr0.52Ti0.48)O3 Thin Films with La0.5Sr0.5CoO3 Buffer Layer

2013 ◽  
Vol 739 ◽  
pp. 42-46 ◽  
Author(s):  
Jie Guo ◽  
Wei Liu ◽  
Shi Qing Man
Keyword(s):  
Thin Film ◽  
Thin Films ◽  
Buffer Layer ◽  
Annealing Temperature ◽  
Perovskite Phase ◽  
Annealing Treatment ◽  
Rf Magnetron Sputtering ◽  
X Rays ◽  
Pzt Thin Film ◽  
Degree Of Crystallization

Lead zirconium titanate Pb (Zr0.52Ti0.48)O3(PZT) thin films have been deposited on Pt/Ti/Si substrate by rf-magnetron sputtering. X rays diffraction revealed that at 600°C the PZT thin film had crystallized into ABO3perovskite phase. Degree of crystallization depended on annealing temperature. The perovskite grains were textured predominantly along the (110) direction. The grain size was about 140 nm and almost unchanged under different annealing temperature. With the annealing temperature increasing, the degree of crystallization was improved. La0.5Sr0.5CoO3(LSCO) thin film was grown on Pt/Ti/Si as buffer layer. PZT with LSCO buffer layer was intensively (110) preferred orientation and the morphology of PZT thin film changed greatly.

Lead deficient PST Thin Films on LSCO/SrTiO3by RF-Sputtering

2003 ◽  
Vol 784 ◽  
Author(s):  
E. Martínez ◽  
O. Blanco ◽  
A. Fundora ◽  
J. M. Siqueiros
Keyword(s):  
Thin Films ◽  
Electrical Properties ◽  
Perovskite Phase ◽  
Rf Sputtering ◽  
Xrd Analysis ◽  
Electrical Performance ◽  
Nominal Composition ◽  
Polarization Voltage ◽  
Chemical Conditions ◽  
Memory Applications

ABSTRACTWe have investigated the structural, chemical and electrical properties of films with Pb0.6Sr0.4TiO3(PST60) nominal composition grown on well texturized LSCO/SrTiO3(STO) substrates by RF-Sputtering. The crystal structure and electrical properties of the PST60 films are remarkably influenced by the texture characteristics of the LSCO films. The structural and ferroelectric characteristics of PST60 thin films are determined to evaluate the potential of this heterostructure for non-volatile memory applications. Epitaxy of LSCO films was confirmed before depositing PST60 films on the above mentioned substrates through 4-Circle X-Ray Diffraction analysis (θ/2θ, ω and φ scans). The XRD analysis performed on the ferroelectric PST60 layer showed that the films are textured and entirely perovskite phase. LSCO and PST60, crystallize in the perovskite structure and their lattice parameters are well matched. This fact renders favorable structural and chemical conditions for the growth of PST60 on LSCO. The electrical performance of the Pt/PST60/LSCO/SrTiO3(001) capacitors was evaluated through Polarization-Voltage (P-V), Current-Voltage (I-V) and Fatigue measurements.

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